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Avoid size mismatches in skeletons #16

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Pull request for series with
subject: Avoid size mismatches in skeletons
version: 3
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=614738

@kernel-patches-bot
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Master branch: 8cbf062
series: https://patchwork.kernel.org/project/netdevbpf/list/?series=614738
version: 3

Pull request is NOT updated. Failed to apply https://patchwork.kernel.org/project/netdevbpf/list/?series=614738
error message:

Cmd('git') failed due to: exit code(128)
  cmdline: git am -3
  stdout: 'Applying: bpftool: bpf skeletons assert type sizes
Using index info to reconstruct a base tree...
M	tools/bpf/bpftool/gen.c
Falling back to patching base and 3-way merge...
Auto-merging tools/bpf/bpftool/gen.c
CONFLICT (content): Merge conflict in tools/bpf/bpftool/gen.c
Patch failed at 0001 bpftool: bpf skeletons assert type sizes
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".'
  stderr: 'error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch'

conflict:

diff --cc tools/bpf/bpftool/gen.c
index 022f30490567,c1440c0d60b5..000000000000
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@@ -1034,20 -1108,16 +1118,31 @@@ static int do_skeleton(int argc, char *
  		\n\
  		\";							    \n\
  		}							    \n\
++<<<<<<< HEAD
 +									    \n\
 +		#ifdef __cplusplus					    \n\
 +		struct %1$s *%1$s::open(const struct bpf_object_open_opts *opts) { return %1$s__open_opts(opts); }\n\
 +		struct %1$s *%1$s::open_and_load() { return %1$s__open_and_load(); }	\n\
 +		int %1$s::load(struct %1$s *skel) { return %1$s__load(skel); }		\n\
 +		int %1$s::attach(struct %1$s *skel) { return %1$s__attach(skel); }	\n\
 +		void %1$s::detach(struct %1$s *skel) { %1$s__detach(skel); }		\n\
 +		void %1$s::destroy(struct %1$s *skel) { %1$s__destroy(skel); }		\n\
 +		const void *%1$s::elf_bytes(size_t *sz) { return %1$s__elf_bytes(sz); } \n\
 +		#endif /* __cplusplus */				    \n\
 +									    \n\
 +		#endif /* %2$s */					    \n\
++=======
+ 		");
+ 
+ 	codegen_asserts(obj, obj_name);
+ 
+ 	codegen("\
+ 		\n\
+ 									\n\
+ 		#endif /* %s */						\n\
++>>>>>>> bpftool: bpf skeletons assert type sizes
  		",
 -		header_guard);
 +		obj_name, header_guard);
  	err = 0;
  out:
  	bpf_object__close(obj);

@kernel-patches-bot
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=614738 expired. Closing PR.

@kernel-patches-bot kernel-patches-bot deleted the series/614304=>bpf-next branch February 18, 2022 09:21
kernel-patches-bot pushed a commit that referenced this pull request Feb 18, 2022
When bringing down the netdevice or system shutdown, a panic can be
triggered while accessing the sysfs path because the device is already
removed.

    [  755.549084] mlx5_core 0000:12:00.1: Shutdown was called
    [  756.404455] mlx5_core 0000:12:00.0: Shutdown was called
    ...
    [  757.937260] BUG: unable to handle kernel NULL pointer dereference at           (null)
    [  758.031397] IP: [<ffffffff8ee11acb>] dma_pool_alloc+0x1ab/0x280

    crash> bt
    ...
    PID: 12649  TASK: ffff8924108f2100  CPU: 1   COMMAND: "amsd"
    ...
     #9 [ffff89240e1a38b0] page_fault at ffffffff8f38c778
        [exception RIP: dma_pool_alloc+0x1ab]
        RIP: ffffffff8ee11acb  RSP: ffff89240e1a3968  RFLAGS: 00010046
        RAX: 0000000000000246  RBX: ffff89243d874100  RCX: 0000000000001000
        RDX: 0000000000000000  RSI: 0000000000000246  RDI: ffff89243d874090
        RBP: ffff89240e1a39c0   R8: 000000000001f080   R9: ffff8905ffc03c00
        R10: ffffffffc04680d4  R11: ffffffff8edde9fd  R12: 00000000000080d0
        R13: ffff89243d874090  R14: ffff89243d874080  R15: 0000000000000000
        ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    #10 [ffff89240e1a39c8] mlx5_alloc_cmd_msg at ffffffffc04680f3 [mlx5_core]
    #11 [ffff89240e1a3a18] cmd_exec at ffffffffc046ad62 [mlx5_core]
    #12 [ffff89240e1a3ab8] mlx5_cmd_exec at ffffffffc046b4fb [mlx5_core]
    #13 [ffff89240e1a3ae8] mlx5_core_access_reg at ffffffffc0475434 [mlx5_core]
    #14 [ffff89240e1a3b40] mlx5e_get_fec_caps at ffffffffc04a7348 [mlx5_core]
    #15 [ffff89240e1a3bb0] get_fec_supported_advertised at ffffffffc04992bf [mlx5_core]
    #16 [ffff89240e1a3c08] mlx5e_get_link_ksettings at ffffffffc049ab36 [mlx5_core]
    #17 [ffff89240e1a3ce8] __ethtool_get_link_ksettings at ffffffff8f25db46
    #18 [ffff89240e1a3d48] speed_show at ffffffff8f277208
    #19 [ffff89240e1a3dd8] dev_attr_show at ffffffff8f0b70e3
    #20 [ffff89240e1a3df8] sysfs_kf_seq_show at ffffffff8eedbedf
    #21 [ffff89240e1a3e18] kernfs_seq_show at ffffffff8eeda596
    #22 [ffff89240e1a3e28] seq_read at ffffffff8ee76d10
    #23 [ffff89240e1a3e98] kernfs_fop_read at ffffffff8eedaef5
    #24 [ffff89240e1a3ed8] vfs_read at ffffffff8ee4e3ff
    #25 [ffff89240e1a3f08] sys_read at ffffffff8ee4f27f
    #26 [ffff89240e1a3f50] system_call_fastpath at ffffffff8f395f92

    crash> net_device.state ffff89443b0c0000
      state = 0x5  (__LINK_STATE_START| __LINK_STATE_NOCARRIER)

To prevent this scenario, we also make sure that the netdevice is present.

Signed-off-by: suresh kumar <suresh2514@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kernel-patches-bot pushed a commit that referenced this pull request Mar 5, 2022
In current async pagefault logic, when a page is ready, KVM relies on
kvm_arch_can_dequeue_async_page_present() to determine whether to deliver
a READY event to the Guest. This function test token value of struct
kvm_vcpu_pv_apf_data, which must be reset to zero by Guest kernel when a
READY event is finished by Guest. If value is zero meaning that a READY
event is done, so the KVM can deliver another.
But the kvm_arch_setup_async_pf() may produce a valid token with zero
value, which is confused with previous mention and may lead the loss of
this READY event.

This bug may cause task blocked forever in Guest:
 INFO: task stress:7532 blocked for more than 1254 seconds.
       Not tainted 5.10.0 #16
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 task:stress          state:D stack:    0 pid: 7532 ppid:  1409
 flags:0x00000080
 Call Trace:
  __schedule+0x1e7/0x650
  schedule+0x46/0xb0
  kvm_async_pf_task_wait_schedule+0xad/0xe0
  ? exit_to_user_mode_prepare+0x60/0x70
  __kvm_handle_async_pf+0x4f/0xb0
  ? asm_exc_page_fault+0x8/0x30
  exc_page_fault+0x6f/0x110
  ? asm_exc_page_fault+0x8/0x30
  asm_exc_page_fault+0x1e/0x30
 RIP: 0033:0x402d00
 RSP: 002b:00007ffd31912500 EFLAGS: 00010206
 RAX: 0000000000071000 RBX: ffffffffffffffff RCX: 00000000021a32b0
 RDX: 000000000007d011 RSI: 000000000007d000 RDI: 00000000021262b0
 RBP: 00000000021262b0 R08: 0000000000000003 R09: 0000000000000086
 R10: 00000000000000eb R11: 00007fefbdf2baa0 R12: 0000000000000000
 R13: 0000000000000002 R14: 000000000007d000 R15: 0000000000001000

Signed-off-by: Liang Zhang <zhangliang5@huawei.com>
Message-Id: <20220222031239.1076682-1-zhangliang5@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 16, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 16, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 16, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 17, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 17, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 17, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 17, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 18, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 19, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-bot pushed a commit that referenced this pull request Mar 21, 2022
The BPF STX/LDX instruction uses offset relative to the FP to address
stack space. Since the BPF_FP locates at the top of the frame, the offset
is usually a negative number. However, arm64 str/ldr immediate instruction
requires that offset be a positive number.  Therefore, this patch tries to
convert the offsets.

The method is to find the negative offset furthest from the FP firstly.
Then add it to the FP, calculate a bottom position, called FPB, and then
adjust the offsets in other STR/LDX instructions relative to FPB.

FPB is saved using the callee-saved register x27 of arm64 which is not
used yet.

Before adjusting the offset, the patch checks every instruction to ensure
that the FP does not change in run-time. If the FP may change, no offset
is adjusted.

For example, for the following bpftrace command:

  bpftrace -e 'kprobe:do_sys_open { printf("opening: %s\n", str(arg1)); }'

Without this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   mov     x25, sp
  1c:   mov     x26, #0x0                       // #0
  20:   bti     j
  24:   sub     sp, sp, #0x90
  28:   add     x19, x0, #0x0
  2c:   mov     x0, #0x0                        // #0
  30:   mov     x10, #0xffffffffffffff78        // #-136
  34:   str     x0, [x25, x10]
  38:   mov     x10, #0xffffffffffffff80        // #-128
  3c:   str     x0, [x25, x10]
  40:   mov     x10, #0xffffffffffffff88        // #-120
  44:   str     x0, [x25, x10]
  48:   mov     x10, #0xffffffffffffff90        // #-112
  4c:   str     x0, [x25, x10]
  50:   mov     x10, #0xffffffffffffff98        // #-104
  54:   str     x0, [x25, x10]
  58:   mov     x10, #0xffffffffffffffa0        // #-96
  5c:   str     x0, [x25, x10]
  60:   mov     x10, #0xffffffffffffffa8        // #-88
  64:   str     x0, [x25, x10]
  68:   mov     x10, #0xffffffffffffffb0        // #-80
  6c:   str     x0, [x25, x10]
  70:   mov     x10, #0xffffffffffffffb8        // #-72
  74:   str     x0, [x25, x10]
  78:   mov     x10, #0xffffffffffffffc0        // #-64
  7c:   str     x0, [x25, x10]
  80:   mov     x10, #0xffffffffffffffc8        // #-56
  84:   str     x0, [x25, x10]
  88:   mov     x10, #0xffffffffffffffd0        // #-48
  8c:   str     x0, [x25, x10]
  90:   mov     x10, #0xffffffffffffffd8        // #-40
  94:   str     x0, [x25, x10]
  98:   mov     x10, #0xffffffffffffffe0        // #-32
  9c:   str     x0, [x25, x10]
  a0:   mov     x10, #0xffffffffffffffe8        // #-24
  a4:   str     x0, [x25, x10]
  a8:   mov     x10, #0xfffffffffffffff0        // #-16
  ac:   str     x0, [x25, x10]
  b0:   mov     x10, #0xfffffffffffffff8        // #-8
  b4:   str     x0, [x25, x10]
  b8:   mov     x10, #0x8                       // #8
  bc:   ldr     x2, [x19, x10]
  [...]

With this patch, jited code(fragment):

   0:   bti     c
   4:   stp     x29, x30, [sp, #-16]!
   8:   mov     x29, sp
   c:   stp     x19, x20, [sp, #-16]!
  10:   stp     x21, x22, [sp, #-16]!
  14:   stp     x25, x26, [sp, #-16]!
  18:   stp     x27, x28, [sp, #-16]!
  1c:   mov     x25, sp
  20:   sub     x27, x25, #0x88
  24:   mov     x26, #0x0                       // #0
  28:   bti     j
  2c:   sub     sp, sp, #0x90
  30:   add     x19, x0, #0x0
  34:   mov     x0, #0x0                        // #0
  38:   str     x0, [x27]
  3c:   str     x0, [x27, #8]
  40:   str     x0, [x27, #16]
  44:   str     x0, [x27, #24]
  48:   str     x0, [x27, #32]
  4c:   str     x0, [x27, #40]
  50:   str     x0, [x27, #48]
  54:   str     x0, [x27, #56]
  58:   str     x0, [x27, #64]
  5c:   str     x0, [x27, #72]
  60:   str     x0, [x27, #80]
  64:   str     x0, [x27, #88]
  68:   str     x0, [x27, #96]
  6c:   str     x0, [x27, #104]
  70:   str     x0, [x27, #112]
  74:   str     x0, [x27, #120]
  78:   str     x0, [x27, #128]
  7c:   ldr     x2, [x19, #8]
  [...]

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request May 12, 2024
Puranjay Mohan says:

====================
bpf: Inline helpers in arm64 and riscv JITs

Changes in v5 -> v6:
arm64 v5: https://lore.kernel.org/all/20240430234739.79185-1-puranjay@kernel.org/
riscv v2: https://lore.kernel.org/all/20240430175834.33152-1-puranjay@kernel.org/
- Combine riscv and arm64 changes in single series
- Some coding style fixes

Changes in v4 -> v5:
v4: https://lore.kernel.org/all/20240429131647.50165-1-puranjay@kernel.org/
- Implement the inlining of the bpf_get_smp_processor_id() in the JIT.

NOTE: This needs to be based on:
https://lore.kernel.org/all/20240430175834.33152-1-puranjay@kernel.org/
to be built.

Manual run of bpf-ci with this series rebased on above:
kernel-patches/bpf#6929

Changes in v3 -> v4:
v3: https://lore.kernel.org/all/20240426121349.97651-1-puranjay@kernel.org/
- Fix coding style issue related to C89 standards.

Changes in v2 -> v3:
v2: https://lore.kernel.org/all/20240424173550.16359-1-puranjay@kernel.org/
- Fixed the xlated dump of percpu mov to "r0 = &(void __percpu *)(r0)"
- Made ARM64 and x86-64 use the same code for inlining. The only difference
  that remains is the per-cpu address of the cpu_number.

Changes in v1 -> v2:
v1: https://lore.kernel.org/all/20240405091707.66675-1-puranjay12@gmail.com/
- Add a patch to inline bpf_get_smp_processor_id()
- Fix an issue in MRS instruction encoding as pointed out by Will
- Remove CONFIG_SMP check because arm64 kernel always compiles with CONFIG_SMP

This series adds the support of internal only per-CPU instructions and inlines
the bpf_get_smp_processor_id() helper call for ARM64 and RISC-V BPF JITs.

Here is an example of calls to bpf_get_smp_processor_id() and
percpu_array_map_lookup_elem() before and after this series on ARM64.

                                         BPF
                                        =====
              BEFORE                                       AFTER
             --------                                     -------

int cpu = bpf_get_smp_processor_id();           int cpu = bpf_get_smp_processor_id();
(85) call bpf_get_smp_processor_id#229032       (85) call bpf_get_smp_processor_id#8

p = bpf_map_lookup_elem(map, &zero);            p = bpf_map_lookup_elem(map, &zero);
(18) r1 = map[id:78]                            (18) r1 = map[id:153]
(18) r2 = map[id:82][0]+65536                   (18) r2 = map[id:157][0]+65536
(85) call percpu_array_map_lookup_elem#313512   (07) r1 += 496
                                                (61) r0 = *(u32 *)(r2 +0)
                                                (35) if r0 >= 0x1 goto pc+5
                                                (67) r0 <<= 3
                                                (0f) r0 += r1
                                                (79) r0 = *(u64 *)(r0 +0)
                                                (bf) r0 = &(void __percpu *)(r0)
                                                (05) goto pc+1
                                                (b7) r0 = 0

                                      ARM64 JIT
                                     ===========

              BEFORE                                       AFTER
             --------                                     -------

int cpu = bpf_get_smp_processor_id();           int cpu = bpf_get_smp_processor_id();
mov     x10, #0xfffffffffffff4d0                mrs     x10, sp_el0
movk    x10, #0x802b, lsl #16                   ldr     w7, [x10, #24]
movk    x10, #0x8000, lsl #32
blr     x10
add     x7, x0, #0x0

p = bpf_map_lookup_elem(map, &zero);            p = bpf_map_lookup_elem(map, &zero);
mov     x0, #0xffff0003ffffffff                 mov     x0, #0xffff0003ffffffff
movk    x0, #0xce5c, lsl #16                    movk    x0, #0xe0f3, lsl #16
movk    x0, #0xca00                             movk    x0, #0x7c00
mov     x1, #0xffff8000ffffffff                 mov     x1, #0xffff8000ffffffff
movk    x1, #0x8bdb, lsl #16                    movk    x1, #0xb0c7, lsl #16
movk    x1, #0x6000                             movk    x1, #0xe000
mov     x10, #0xffffffffffff3ed0                add     x0, x0, #0x1f0
movk    x10, #0x802d, lsl #16                   ldr     w7, [x1]
movk    x10, #0x8000, lsl #32                   cmp     x7, #0x1
blr     x10                                     b.cs    0x0000000000000090
add     x7, x0, #0x0                            lsl     x7, x7, #3
                                                add     x7, x7, x0
                                                ldr     x7, [x7]
                                                mrs     x10, tpidr_el1
                                                add     x7, x7, x10
                                                b       0x0000000000000094
                                                mov     x7, #0x0

              Performance improvement found using benchmark[1]

./benchs/run_bench_trigger.sh glob-arr-inc arr-inc hash-inc

  +---------------+-------------------+-------------------+--------------+
  |      Name     |      Before       |        After      |   % change   |
  |---------------+-------------------+-------------------+--------------|
  | glob-arr-inc  | 23.380 ± 1.675M/s | 25.893 ± 0.026M/s |   + 10.74%   |
  | arr-inc       | 23.928 ± 0.034M/s | 25.213 ± 0.063M/s |   + 5.37%    |
  | hash-inc      | 12.352 ± 0.005M/s | 12.609 ± 0.013M/s |   + 2.08%    |
  +---------------+-------------------+-------------------+--------------+

[1] anakryiko/linux@8dec900975ef

             RISCV64 JIT output for `call bpf_get_smp_processor_id`
            =======================================================

                  Before                           After
                 --------                         -------

           auipc   t1,0x848c                  ld    a5,32(tp)
           jalr    604(t1)
           mv      a5,a0

  Benchmark using [1] on Qemu.

  ./benchs/run_bench_trigger.sh glob-arr-inc arr-inc hash-inc

  +---------------+------------------+------------------+--------------+
  |      Name     |     Before       |       After      |   % change   |
  |---------------+------------------+------------------+--------------|
  | glob-arr-inc  | 1.077 ± 0.006M/s | 1.336 ± 0.010M/s |   + 24.04%   |
  | arr-inc       | 1.078 ± 0.002M/s | 1.332 ± 0.015M/s |   + 23.56%   |
  | hash-inc      | 0.494 ± 0.004M/s | 0.653 ± 0.001M/s |   + 32.18%   |
  +---------------+------------------+------------------+--------------+
====================

Link: https://lore.kernel.org/r/20240502151854.9810-1-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request May 14, 2024
…rnel/git/netfilter/nf-next

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next:

Patch #1 skips transaction if object type provides no .update interface.

Patch #2 skips NETDEV_CHANGENAME which is unused.

Patch #3 enables conntrack to handle Multicast Router Advertisements and
	 Multicast Router Solicitations from the Multicast Router Discovery
	 protocol (RFC4286) as untracked opposed to invalid packets.
	 From Linus Luessing.

Patch #4 updates DCCP conntracker to mark invalid as invalid, instead of
	 dropping them, from Jason Xing.

Patch #5 uses NF_DROP instead of -NF_DROP since NF_DROP is 0,
	 also from Jason.

Patch #6 removes reference in netfilter's sysctl documentation on pickup
	 entries which were already removed by Florian Westphal.

Patch #7 removes check for IPS_OFFLOAD flag to disable early drop which
	 allows to evict entries from the conntrack table,
	 also from Florian.

Patches #8 to #16 updates nf_tables pipapo set backend to allocate
	 the datastructure copy on-demand from preparation phase,
	 to better deal with OOM situations where .commit step is too late
	 to fail. Series from Florian Westphal.

Patch #17 adds a selftest with packetdrill to cover conntrack TCP state
	 transitions, also from Florian.

Patch #18 use GFP_KERNEL to clone elements from control plane to avoid
	 quick atomic reserves exhaustion with large sets, reporter refers
	 to million entries magnitude.

* tag 'nf-next-24-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nf_tables: allow clone callbacks to sleep
  selftests: netfilter: add packetdrill based conntrack tests
  netfilter: nft_set_pipapo: remove dirty flag
  netfilter: nft_set_pipapo: move cloning of match info to insert/removal path
  netfilter: nft_set_pipapo: prepare pipapo_get helper for on-demand clone
  netfilter: nft_set_pipapo: merge deactivate helper into caller
  netfilter: nft_set_pipapo: prepare walk function for on-demand clone
  netfilter: nft_set_pipapo: prepare destroy function for on-demand clone
  netfilter: nft_set_pipapo: make pipapo_clone helper return NULL
  netfilter: nft_set_pipapo: move prove_locking helper around
  netfilter: conntrack: remove flowtable early-drop test
  netfilter: conntrack: documentation: remove reference to non-existent sysctl
  netfilter: use NF_DROP instead of -NF_DROP
  netfilter: conntrack: dccp: try not to drop skb in conntrack
  netfilter: conntrack: fix ct-state for ICMPv6 Multicast Router Discovery
  netfilter: nf_tables: remove NETDEV_CHANGENAME from netdev chain event handler
  netfilter: nf_tables: skip transaction if update object is not implemented
====================

Link: https://lore.kernel.org/r/20240512161436.168973-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request May 28, 2024
ui_browser__show() is capturing the input title that is stack allocated
memory in hist_browser__run().

Avoid a use after return by strdup-ing the string.

Committer notes:

Further explanation from Ian Rogers:

My command line using tui is:
$ sudo bash -c 'rm /tmp/asan.log*; export
ASAN_OPTIONS="log_path=/tmp/asan.log"; /tmp/perf/perf mem record -a
sleep 1; /tmp/perf/perf mem report'
I then go to the perf annotate view and quit. This triggers the asan
error (from the log file):
```
==1254591==ERROR: AddressSanitizer: stack-use-after-return on address
0x7f2813331920 at pc 0x7f28180
65991 bp 0x7fff0a21c750 sp 0x7fff0a21bf10
READ of size 80 at 0x7f2813331920 thread T0
    #0 0x7f2818065990 in __interceptor_strlen
../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:461
    #1 0x7f2817698251 in SLsmg_write_wrapped_string
(/lib/x86_64-linux-gnu/libslang.so.2+0x98251)
    #2 0x7f28176984b9 in SLsmg_write_nstring
(/lib/x86_64-linux-gnu/libslang.so.2+0x984b9)
    #3 0x55c94045b365 in ui_browser__write_nstring ui/browser.c:60
    #4 0x55c94045c558 in __ui_browser__show_title ui/browser.c:266
    #5 0x55c94045c776 in ui_browser__show ui/browser.c:288
    #6 0x55c94045c06d in ui_browser__handle_resize ui/browser.c:206
    #7 0x55c94047979b in do_annotate ui/browsers/hists.c:2458
    #8 0x55c94047fb17 in evsel__hists_browse ui/browsers/hists.c:3412
    #9 0x55c940480a0c in perf_evsel_menu__run ui/browsers/hists.c:3527
    #10 0x55c940481108 in __evlist__tui_browse_hists ui/browsers/hists.c:3613
    #11 0x55c9404813f7 in evlist__tui_browse_hists ui/browsers/hists.c:3661
    #12 0x55c93ffa253f in report__browse_hists tools/perf/builtin-report.c:671
    #13 0x55c93ffa58ca in __cmd_report tools/perf/builtin-report.c:1141
    #14 0x55c93ffaf159 in cmd_report tools/perf/builtin-report.c:1805
    #15 0x55c94000c05c in report_events tools/perf/builtin-mem.c:374
    #16 0x55c94000d96d in cmd_mem tools/perf/builtin-mem.c:516
    #17 0x55c9400e44ee in run_builtin tools/perf/perf.c:350
    #18 0x55c9400e4a5a in handle_internal_command tools/perf/perf.c:403
    #19 0x55c9400e4e22 in run_argv tools/perf/perf.c:447
    #20 0x55c9400e53ad in main tools/perf/perf.c:561
    #21 0x7f28170456c9 in __libc_start_call_main
../sysdeps/nptl/libc_start_call_main.h:58
    #22 0x7f2817045784 in __libc_start_main_impl ../csu/libc-start.c:360
    #23 0x55c93ff544c0 in _start (/tmp/perf/perf+0x19a4c0) (BuildId:
84899b0e8c7d3a3eaa67b2eb35e3d8b2f8cd4c93)

Address 0x7f2813331920 is located in stack of thread T0 at offset 32 in frame
    #0 0x55c94046e85e in hist_browser__run ui/browsers/hists.c:746

  This frame has 1 object(s):
    [32, 192) 'title' (line 747) <== Memory access at offset 32 is
inside this variable
HINT: this may be a false positive if your program uses some custom
stack unwind mechanism, swapcontext or vfork
```
hist_browser__run isn't on the stack so the asan error looks legit.
There's no clean init/exit on struct ui_browser so I may be trading a
use-after-return for a memory leak, but that seems look a good trade
anyway.

Fixes: 05e8b08 ("perf ui browser: Stop using 'self'")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Li Dong <lidong@vivo.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Paran Lee <p4ranlee@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sun Haiyong <sunhaiyong@loongson.cn>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240507183545.1236093-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 15, 2024
We have been seeing crashes on duplicate keys in
btrfs_set_item_key_safe():

  BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192)
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.c:2620!
  invalid opcode: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014
  RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs]

With the following stack trace:

  #0  btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4)
  #1  btrfs_drop_extents (fs/btrfs/file.c:411:4)
  #2  log_one_extent (fs/btrfs/tree-log.c:4732:9)
  #3  btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9)
  #4  btrfs_log_inode (fs/btrfs/tree-log.c:6626:9)
  #5  btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8)
  #6  btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8)
  #7  btrfs_sync_file (fs/btrfs/file.c:1933:8)
  #8  vfs_fsync_range (fs/sync.c:188:9)
  #9  vfs_fsync (fs/sync.c:202:9)
  #10 do_fsync (fs/sync.c:212:9)
  #11 __do_sys_fdatasync (fs/sync.c:225:9)
  #12 __se_sys_fdatasync (fs/sync.c:223:1)
  #13 __x64_sys_fdatasync (fs/sync.c:223:1)
  #14 do_syscall_x64 (arch/x86/entry/common.c:52:14)
  #15 do_syscall_64 (arch/x86/entry/common.c:83:7)
  #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121)

So we're logging a changed extent from fsync, which is splitting an
extent in the log tree. But this split part already exists in the tree,
triggering the BUG().

This is the state of the log tree at the time of the crash, dumped with
drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py)
to get more details than btrfs_print_leaf() gives us:

  >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"])
  leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610
  leaf 33439744 flags 0x100000000000000
  fs uuid e5bd3946-400c-4223-8923-190ef1f18677
  chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
          item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160
                  generation 7 transid 9 size 8192 nbytes 8473563889606862198
                  block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
                  sequence 204 flags 0x10(PREALLOC)
                  atime 1716417703.220000000 (2024-05-22 15:41:43)
                  ctime 1716417704.983333333 (2024-05-22 15:41:44)
                  mtime 1716417704.983333333 (2024-05-22 15:41:44)
                  otime 17592186044416.000000000 (559444-03-08 01:40:16)
          item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13
                  index 195 namelen 3 name: 193
          item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37
                  location key (0 UNKNOWN.0 0) type XATTR
                  transid 7 data_len 1 name_len 6
                  name: user.a
                  data a
          item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53
                  generation 9 type 1 (regular)
                  extent data disk byte 303144960 nr 12288
                  extent data offset 0 nr 4096 ram 12288
                  extent compression 0 (none)
          item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 4096 nr 8192
          item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 8192 nr 4096
  ...

So the real problem happened earlier: notice that items 4 (4k-12k) and 5
(8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and
item 5 starts at i_size.

Here is the state of the filesystem tree at the time of the crash:

  >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root
  >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0))
  >>> print_extent_buffer(nodes[0])
  leaf 30425088 level 0 items 184 generation 9 owner 5
  leaf 30425088 flags 0x100000000000000
  fs uuid e5bd3946-400c-4223-8923-190ef1f18677
  chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da
  	...
          item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160
                  generation 7 transid 7 size 4096 nbytes 12288
                  block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0
                  sequence 6 flags 0x10(PREALLOC)
                  atime 1716417703.220000000 (2024-05-22 15:41:43)
                  ctime 1716417703.220000000 (2024-05-22 15:41:43)
                  mtime 1716417703.220000000 (2024-05-22 15:41:43)
                  otime 1716417703.220000000 (2024-05-22 15:41:43)
          item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13
                  index 195 namelen 3 name: 193
          item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37
                  location key (0 UNKNOWN.0 0) type XATTR
                  transid 7 data_len 1 name_len 6
                  name: user.a
                  data a
          item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53
                  generation 9 type 1 (regular)
                  extent data disk byte 303144960 nr 12288
                  extent data offset 0 nr 8192 ram 12288
                  extent compression 0 (none)
          item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53
                  generation 9 type 2 (prealloc)
                  prealloc data disk byte 303144960 nr 12288
                  prealloc data offset 8192 nr 4096

Item 5 in the log tree corresponds to item 183 in the filesystem tree,
but nothing matches item 4. Furthermore, item 183 is the last item in
the leaf.

btrfs_log_prealloc_extents() is responsible for logging prealloc extents
beyond i_size. It first truncates any previously logged prealloc extents
that start beyond i_size. Then, it walks the filesystem tree and copies
the prealloc extent items to the log tree.

If it hits the end of a leaf, then it calls btrfs_next_leaf(), which
unlocks the tree and does another search. However, while the filesystem
tree is unlocked, an ordered extent completion may modify the tree. In
particular, it may insert an extent item that overlaps with an extent
item that was already copied to the log tree.

This may manifest in several ways depending on the exact scenario,
including an EEXIST error that is silently translated to a full sync,
overlapping items in the log tree, or this crash. This particular crash
is triggered by the following sequence of events:

- Initially, the file has i_size=4k, a regular extent from 0-4k, and a
  prealloc extent beyond i_size from 4k-12k. The prealloc extent item is
  the last item in its B-tree leaf.
- The file is fsync'd, which copies its inode item and both extent items
  to the log tree.
- An xattr is set on the file, which sets the
  BTRFS_INODE_COPY_EVERYTHING flag.
- The range 4k-8k in the file is written using direct I/O. i_size is
  extended to 8k, but the ordered extent is still in flight.
- The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this
  calls copy_inode_items_to_log(), which calls
  btrfs_log_prealloc_extents().
- btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the
  filesystem tree. Since it starts before i_size, it skips it. Since it
  is the last item in its B-tree leaf, it calls btrfs_next_leaf().
- btrfs_next_leaf() unlocks the path.
- The ordered extent completion runs, which converts the 4k-8k part of
  the prealloc extent to written and inserts the remaining prealloc part
  from 8k-12k.
- btrfs_next_leaf() does a search and finds the new prealloc extent
  8k-12k.
- btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into
  the log tree. Note that it overlaps with the 4k-12k prealloc extent
  that was copied to the log tree by the first fsync.
- fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k
  extent that was written.
- This tries to drop the range 4k-8k in the log tree, which requires
  adjusting the start of the 4k-12k prealloc extent in the log tree to
  8k.
- btrfs_set_item_key_safe() sees that there is already an extent
  starting at 8k in the log tree and calls BUG().

Fix this by detecting when we're about to insert an overlapping file
extent item in the log tree and truncating the part that would overlap.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 15, 2024
When queues are started, netif_napi_add() and napi_enable() are called.
If there are 4 queues and only 3 queues are used for the current
configuration, only 3 queues' napi should be registered and enabled.
The ionic_qcq_enable() checks whether the .poll pointer is not NULL for
enabling only the using queue' napi. Unused queues' napi will not be
registered by netif_napi_add(), so the .poll pointer indicates NULL.
But it couldn't distinguish whether the napi was unregistered or not
because netif_napi_del() doesn't reset the .poll pointer to NULL.
So, ionic_qcq_enable() calls napi_enable() for the queue, which was
unregistered by netif_napi_del().

Reproducer:
   ethtool -L <interface name> rx 1 tx 1 combined 0
   ethtool -L <interface name> rx 0 tx 0 combined 1
   ethtool -L <interface name> rx 0 tx 0 combined 4

Splat looks like:
kernel BUG at net/core/dev.c:6666!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 3 PID: 1057 Comm: kworker/3:3 Not tainted 6.10.0-rc2+ #16
Workqueue: events ionic_lif_deferred_work [ionic]
RIP: 0010:napi_enable+0x3b/0x40
Code: 48 89 c2 48 83 e2 f6 80 b9 61 09 00 00 00 74 0d 48 83 bf 60 01 00 00 00 74 03 80 ce 01 f0 4f
RSP: 0018:ffffb6ed83227d48 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff97560cda0828 RCX: 0000000000000029
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff97560cda0a28
RBP: ffffb6ed83227d50 R08: 0000000000000400 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: ffff97560ce3c1a0 R14: 0000000000000000 R15: ffff975613ba0a20
FS:  0000000000000000(0000) GS:ffff975d5f780000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f734ee200 CR3: 0000000103e50000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
 <TASK>
 ? die+0x33/0x90
 ? do_trap+0xd9/0x100
 ? napi_enable+0x3b/0x40
 ? do_error_trap+0x83/0xb0
 ? napi_enable+0x3b/0x40
 ? napi_enable+0x3b/0x40
 ? exc_invalid_op+0x4e/0x70
 ? napi_enable+0x3b/0x40
 ? asm_exc_invalid_op+0x16/0x20
 ? napi_enable+0x3b/0x40
 ionic_qcq_enable+0xb7/0x180 [ionic 59bdfc8a035436e1c4224ff7d10789e3f14643f8]
 ionic_start_queues+0xc4/0x290 [ionic 59bdfc8a035436e1c4224ff7d10789e3f14643f8]
 ionic_link_status_check+0x11c/0x170 [ionic 59bdfc8a035436e1c4224ff7d10789e3f14643f8]
 ionic_lif_deferred_work+0x129/0x280 [ionic 59bdfc8a035436e1c4224ff7d10789e3f14643f8]
 process_one_work+0x145/0x360
 worker_thread+0x2bb/0x3d0
 ? __pfx_worker_thread+0x10/0x10
 kthread+0xcc/0x100
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x2d/0x50
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30

Fixes: 0f3154e ("ionic: Add Tx and Rx handling")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20240612060446.1754392-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 19, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 21, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 21, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 21, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 21, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 21, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 21, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 21, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 21, 2024
On ARM64, the pointer to task_struct is always available in the sp_el0
register and therefore the calls to bpf_get_current_task() and
bpf_get_current_task_btf() can be inlined into a single MRS instruction.

Here is the difference before and after this change:

Before:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mov     x10, #0xffffffffffff7978        // #-34440
  58:   movk    x10, #0x802b, lsl #16
  5c:   movk    x10, #0x8000, lsl #32
  60:   blr     x10          -------------->    0xffff8000802b7978 <+0>:     mrs     x0, sp_el0
  64:   add     x7, x0, #0x0 <--------------    0xffff8000802b797c <+4>:     ret

After:

; struct task_struct *task = bpf_get_current_task_btf();
  54:   mrs     x7, sp_el0

This shows around 1% performance improvement in artificial microbenchmark.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240619131334.4297-1-puranjay@kernel.org
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jun 28, 2024
The code in ocfs2_dio_end_io_write() estimates number of necessary
transaction credits using ocfs2_calc_extend_credits().  This however does
not take into account that the IO could be arbitrarily large and can
contain arbitrary number of extents.

Extent tree manipulations do often extend the current transaction but not
in all of the cases.  For example if we have only single block extents in
the tree, ocfs2_mark_extent_written() will end up calling
ocfs2_replace_extent_rec() all the time and we will never extend the
current transaction and eventually exhaust all the transaction credits if
the IO contains many single block extents.  Once that happens a
WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in
jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to
this error.  This was actually triggered by one of our customers on a
heavily fragmented OCFS2 filesystem.

To fix the issue make sure the transaction always has enough credits for
one extent insert before each call of ocfs2_mark_extent_written().

Heming Zhao said:

------
PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error"

PID: xxx  TASK: xxxx  CPU: 5  COMMAND: "SubmitThread-CA"
  #0 machine_kexec at ffffffff8c069932
  #1 __crash_kexec at ffffffff8c1338fa
  #2 panic at ffffffff8c1d69b9
  #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2]
  #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2]
  #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2]
  #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2]
  #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2]
  #8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2]
  #9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2]
#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2]
#11 dio_complete at ffffffff8c2b9fa7
#12 do_blockdev_direct_IO at ffffffff8c2bc09f
#13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2]
#14 generic_file_direct_write at ffffffff8c1dcf14
#15 __generic_file_write_iter at ffffffff8c1dd07b
#16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2]
#17 aio_write at ffffffff8c2cc72e
#18 kmem_cache_alloc at ffffffff8c248dde
#19 do_io_submit at ffffffff8c2ccada
#20 do_syscall_64 at ffffffff8c004984
#21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba

Link: https://lkml.kernel.org/r/20240617095543.6971-1-jack@suse.cz
Link: https://lkml.kernel.org/r/20240614145243.8837-1-jack@suse.cz
Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jul 9, 2024
…rnel/git/netfilter/nf-next into main

Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter/IPVS updates for net-next:

Patch #1 to #11 to shrink memory consumption for transaction objects:

  struct nft_trans_chain { /* size: 120 (-32), cachelines: 2, members: 10 */
  struct nft_trans_elem { /* size: 72 (-40), cachelines: 2, members: 4 */
  struct nft_trans_flowtable { /* size: 80 (-48), cachelines: 2, members: 5 */
  struct nft_trans_obj { /* size: 72 (-40), cachelines: 2, members: 4 */
  struct nft_trans_rule { /* size: 80 (-32), cachelines: 2, members: 6 */
  struct nft_trans_set { /* size: 96 (-24), cachelines: 2, members: 8 */
  struct nft_trans_table { /* size: 56 (-40), cachelines: 1, members: 2 */

  struct nft_trans_elem can now be allocated from kmalloc-96 instead of
  kmalloc-128 slab.

  Series from Florian Westphal. For the record, I have mangled patch #1
  to add nft_trans_container_*() and use if for every transaction object.
   I have also added BUILD_BUG_ON to ensure struct nft_trans always comes
  at the beginning of the container transaction object. And few minor
  cleanups, any new bugs are of my own.

Patch #12 simplify check for SCTP GSO in IPVS, from Ismael Luceno.

Patch #13 nf_conncount key length remains in the u32 bound, from Yunjian Wang.

Patch #14 removes unnecessary check for CTA_TIMEOUT_L3PROTO when setting
          default conntrack timeouts via nfnetlink_cttimeout API, from
          Lin Ma.

Patch #15 updates NFT_SECMARK_CTX_MAXLEN to 4096, SELinux could use
          larger secctx names than the existing 256 bytes length.

Patch #16 adds a selftest to exercise nfnetlink_queue listeners leaving
          nfnetlink_queue, from Florian Westphal.

Patch #17 increases hitcount from 255 to 65535 in xt_recent, from Phil Sutter.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jul 12, 2024
Run bloom_filter_map selftests (./test_progs -t bloom_filter_map) on a
Loongarch platform, an error message "JIT doesn't support bpf-to-bpf calls"
is got in user space, together with an unexpected errno EINVAL (22), not
ENOTSUPP (524):

 libbpf: prog 'inner_map': BPF program load failed: Invalid argument
 libbpf: prog 'inner_map': -- BEGIN PROG LOAD LOG --
 JIT doesn't support bpf-to-bpf calls
 callbacks are not allowed in non-JITed programs
 processed 37 insns (limit 1000000) max_states_per_insn 1 total_states
 -- END PROG LOAD LOG --
 libbpf: prog 'inner_map': failed to load: -22
 libbpf: failed to load object 'bloom_filter_map'
 libbpf: failed to load BPF skeleton 'bloom_filter_map': -22
 setup_progs:FAIL:bloom_filter_map__open_and_load unexpected error: -22
 #16      bloom_filter_map:FAIL

Although in jit_subprogs(), the error number does be set as "ENOTSUPP":

	verbose(env, "JIT doesn't support bpf-to-bpf calls\n");
	err = -ENOTSUPP;
	goto out_free;

But afterwards in fixup_call_args(), such error number is ignored, and
overwritten as "-EINVAL":

	verbose(env, "callbacks are not allowed in non-JITed programs\n");
	return -EINVAL;

This patch fixes this by changing return values of fixup_call_args() from
"-EINVAL" to "err ?: -EINVAL". With this change, errno 524 is got in user
space now:

 libbpf: prog 'inner_map': BPF program load failed: unknown error (-524)
 libbpf: prog 'inner_map': -- BEGIN PROG LOAD LOG --
 JIT doesn't support bpf-to-bpf calls
 processed 37 insns (limit 1000000) max_states_per_insn 1 total_states
 -- END PROG LOAD LOG --
 libbpf: prog 'inner_map': failed to load: -524
 libbpf: failed to load object 'bloom_filter_map'
 libbpf: failed to load BPF skeleton 'bloom_filter_map': -524
 setup_progs:FAIL:bloom_filter_map__open_and_load unexpected error: -524

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jul 12, 2024
Run bloom_filter_map selftests (./test_progs -t bloom_filter_map) on a
Loongarch platform, an error message "JIT doesn't support bpf-to-bpf calls"
is got in user space, together with an unexpected errno EINVAL (22), not
ENOTSUPP (524):

 libbpf: prog 'inner_map': BPF program load failed: Invalid argument
 libbpf: prog 'inner_map': -- BEGIN PROG LOAD LOG --
 JIT doesn't support bpf-to-bpf calls
 callbacks are not allowed in non-JITed programs
 processed 37 insns (limit 1000000) max_states_per_insn 1 total_states
 -- END PROG LOAD LOG --
 libbpf: prog 'inner_map': failed to load: -22
 libbpf: failed to load object 'bloom_filter_map'
 libbpf: failed to load BPF skeleton 'bloom_filter_map': -22
 setup_progs:FAIL:bloom_filter_map__open_and_load unexpected error: -22
 #16      bloom_filter_map:FAIL

Although the return value of jit_subprogs() does be set as "ENOTSUPP":

	verbose(env, "JIT doesn't support bpf-to-bpf calls\n");
	err = -ENOTSUPP;
	goto out_free;

But afterwards in fixup_call_args(), the return value of jit_subprogs()
is ignored, and overwritten as "-EINVAL":

	verbose(env, "callbacks are not allowed in non-JITed programs\n");
	return -EINVAL;

This patch fixes this by changing return values of fixup_call_args() from
"-EINVAL" to "err ?: -EINVAL". With this change, errno 524 is got in user
space now:

 libbpf: prog 'inner_map': BPF program load failed: unknown error (-524)
 libbpf: prog 'inner_map': -- BEGIN PROG LOAD LOG --
 JIT doesn't support bpf-to-bpf calls
 processed 37 insns (limit 1000000) max_states_per_insn 1 total_states
 -- END PROG LOAD LOG --
 libbpf: prog 'inner_map': failed to load: -524
 libbpf: failed to load object 'bloom_filter_map'
 libbpf: failed to load BPF skeleton 'bloom_filter_map': -524
 setup_progs:FAIL:bloom_filter_map__open_and_load unexpected error: -524

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Jul 12, 2024
Run bloom_filter_map selftests (./test_progs -t bloom_filter_map) on a
Loongarch platform, an error message "JIT doesn't support bpf-to-bpf calls"
is got in user space, together with an unexpected errno EINVAL (22), not
ENOTSUPP (524):

 libbpf: prog 'inner_map': BPF program load failed: Invalid argument
 libbpf: prog 'inner_map': -- BEGIN PROG LOAD LOG --
 JIT doesn't support bpf-to-bpf calls
 callbacks are not allowed in non-JITed programs
 processed 37 insns (limit 1000000) max_states_per_insn 1 total_states
 -- END PROG LOAD LOG --
 libbpf: prog 'inner_map': failed to load: -22
 libbpf: failed to load object 'bloom_filter_map'
 libbpf: failed to load BPF skeleton 'bloom_filter_map': -22
 setup_progs:FAIL:bloom_filter_map__open_and_load unexpected error: -22
 #16      bloom_filter_map:FAIL

Although the return value of jit_subprogs() does be set as "ENOTSUPP":

	verbose(env, "JIT doesn't support bpf-to-bpf calls\n");
	err = -ENOTSUPP;
	goto out_free;

But afterwards in fixup_call_args(), the return value of jit_subprogs()
is ignored, and overwritten as "-EINVAL":

	verbose(env, "callbacks are not allowed in non-JITed programs\n");
	return -EINVAL;

This patch fixes this by changing return values of fixup_call_args() from
"-EINVAL" to "err ?: -EINVAL". With this change, errno 524 is got in user
space now:

 libbpf: prog 'inner_map': BPF program load failed: unknown error (-524)
 libbpf: prog 'inner_map': -- BEGIN PROG LOAD LOG --
 JIT doesn't support bpf-to-bpf calls
 processed 37 insns (limit 1000000) max_states_per_insn 1 total_states
 -- END PROG LOAD LOG --
 libbpf: prog 'inner_map': failed to load: -524
 libbpf: failed to load object 'bloom_filter_map'
 libbpf: failed to load BPF skeleton 'bloom_filter_map': -524
 setup_progs:FAIL:bloom_filter_map__open_and_load unexpected error: -524

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 26, 2024
The arm64 jit blindly saves/restores all callee-saved registers, making
the jited result looks a bit too compliated. For example, for an empty
prog, the jited result is:

   0:   bti jc
   4:   mov     x9, lr
   8:   nop
   c:   paciasp
  10:   stp     fp, lr, [sp, #-16]!
  14:   mov     fp, sp
  18:   stp     x19, x20, [sp, #-16]!
  1c:   stp     x21, x22, [sp, #-16]!
  20:   stp     x26, x25, [sp, #-16]!
  24:   mov     x26, #0
  28:   stp     x26, x25, [sp, #-16]!
  2c:   mov     x26, sp
  30:   stp     x27, x28, [sp, #-16]!
  34:   mov     x25, sp
  38:   bti j 		// tailcall target
  3c:   sub     sp, sp, #0
  40:   mov     x7, #0
  44:   add     sp, sp, #0
  48:   ldp     x27, x28, [sp], #16
  4c:   ldp     x26, x25, [sp], #16
  50:   ldp     x26, x25, [sp], #16
  54:   ldp     x21, x22, [sp], #16
  58:   ldp     x19, x20, [sp], #16
  5c:   ldp     fp, lr, [sp], #16
  60:   mov     x0, x7
  64:   autiasp
  68:   ret

Clearly, there is no need to save/restore unused callee-saved registers.
This patch does this change, making the jited image to only save/restore
the callee-saved registers it uses.

Now the jited result of empty prog is:

   0:   bti jc
   4:   mov     x9, lr
   8:   nop
   c:   paciasp
  10:   stp     fp, lr, [sp, #-16]!
  14:   mov     fp, sp
  18:   stp     xzr, x26, [sp, #-16]!
  1c:   mov     x26, sp
  20:   bti j		// tailcall target
  24:   mov     x7, #0
  28:   ldp     xzr, x26, [sp], #16
  2c:   ldp     fp, lr, [sp], #16
  30:   mov     x0, x7
  34:   autiasp
  38:   ret

Since bpf prog saves/restores its own callee-saved registers as needed,
to make tailcall work correctly, the caller needs to restore its saved
registers before tailcall, and the callee needs to save its callee-saved
registers after tailcall. This extra restoring/saving instructions
increases preformance overhead.

[1] provides 2 benchmarks for tailcall scenarios. Below is the perf
number measured in an arm64 KVM guest. The result indicates that the
performance difference before and after the patch in typical tailcall
scenarios is negligible.

- Before:

 Performance counter stats for './test_progs -t tailcalls' (5 runs):

           4313.43 msec task-clock                       #    0.874 CPUs utilized               ( +-  0.16% )
               574      context-switches                 #  133.073 /sec                        ( +-  1.14% )
                 0      cpu-migrations                   #    0.000 /sec
               538      page-faults                      #  124.727 /sec                        ( +-  0.57% )
       10697772784      cycles                           #    2.480 GHz                         ( +-  0.22% )  (61.19%)
       25511241955      instructions                     #    2.38  insn per cycle              ( +-  0.08% )  (66.70%)
        5108910557      branches                         #    1.184 G/sec                       ( +-  0.08% )  (72.38%)
           2800459      branch-misses                    #    0.05% of all branches             ( +-  0.51% )  (72.36%)
                        TopDownL1                 #     0.60 retiring                    ( +-  0.09% )  (66.84%)
                                                  #     0.21 frontend_bound              ( +-  0.15% )  (61.31%)
                                                  #     0.12 bad_speculation             ( +-  0.08% )  (50.11%)
                                                  #     0.07 backend_bound               ( +-  0.16% )  (33.30%)
        8274201819      L1-dcache-loads                  #    1.918 G/sec                       ( +-  0.18% )  (33.15%)
            468268      L1-dcache-load-misses            #    0.01% of all L1-dcache accesses   ( +-  4.69% )  (33.16%)
            385383      LLC-loads                        #   89.345 K/sec                       ( +-  5.22% )  (33.16%)
             38296      LLC-load-misses                  #    9.94% of all LL-cache accesses    ( +- 42.52% )  (38.69%)
        6886576501      L1-icache-loads                  #    1.597 G/sec                       ( +-  0.35% )  (38.69%)
           1848585      L1-icache-load-misses            #    0.03% of all L1-icache accesses   ( +-  4.52% )  (44.23%)
        9043645883      dTLB-loads                       #    2.097 G/sec                       ( +-  0.10% )  (44.33%)
            416672      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  5.15% )  (49.89%)
        6925626111      iTLB-loads                       #    1.606 G/sec                       ( +-  0.35% )  (55.46%)
             66220      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  1.88% )  (55.50%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

            4.9372 +- 0.0526 seconds time elapsed  ( +-  1.07% )

 Performance counter stats for './test_progs -t flow_dissector' (5 runs):

          10924.50 msec task-clock                       #    0.945 CPUs utilized               ( +-  0.08% )
               603      context-switches                 #   55.197 /sec                        ( +-  1.13% )
                 0      cpu-migrations                   #    0.000 /sec
               566      page-faults                      #   51.810 /sec                        ( +-  0.42% )
       27381270695      cycles                           #    2.506 GHz                         ( +-  0.18% )  (60.46%)
       56996583922      instructions                     #    2.08  insn per cycle              ( +-  0.21% )  (66.11%)
       10321647567      branches                         #  944.816 M/sec                       ( +-  0.17% )  (71.79%)
           3347735      branch-misses                    #    0.03% of all branches             ( +-  3.72% )  (72.15%)
                        TopDownL1                 #     0.52 retiring                    ( +-  0.13% )  (66.74%)
                                                  #     0.27 frontend_bound              ( +-  0.14% )  (61.27%)
                                                  #     0.14 bad_speculation             ( +-  0.19% )  (50.36%)
                                                  #     0.07 backend_bound               ( +-  0.42% )  (33.89%)
       18740797617      L1-dcache-loads                  #    1.715 G/sec                       ( +-  0.43% )  (33.71%)
          13715669      L1-dcache-load-misses            #    0.07% of all L1-dcache accesses   ( +- 32.85% )  (33.34%)
           4087551      LLC-loads                        #  374.164 K/sec                       ( +- 29.53% )  (33.26%)
            267906      LLC-load-misses                  #    6.55% of all LL-cache accesses    ( +- 23.90% )  (38.76%)
       15811864229      L1-icache-loads                  #    1.447 G/sec                       ( +-  0.12% )  (38.73%)
           2976833      L1-icache-load-misses            #    0.02% of all L1-icache accesses   ( +-  9.73% )  (44.22%)
       20138907471      dTLB-loads                       #    1.843 G/sec                       ( +-  0.18% )  (44.15%)
            732850      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +- 11.18% )  (49.64%)
       15895726702      iTLB-loads                       #    1.455 G/sec                       ( +-  0.15% )  (55.13%)
            152075      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  4.71% )  (54.98%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

           11.5613 +- 0.0317 seconds time elapsed  ( +-  0.27% )

- After:

 Performance counter stats for './test_progs -t tailcalls' (5 runs):

           4278.78 msec task-clock                       #    0.871 CPUs utilized               ( +-  0.15% )
               569      context-switches                 #  132.982 /sec                        ( +-  0.58% )
                 0      cpu-migrations                   #    0.000 /sec
               539      page-faults                      #  125.970 /sec                        ( +-  0.43% )
       10588986432      cycles                           #    2.475 GHz                         ( +-  0.20% )  (60.91%)
       25303825043      instructions                     #    2.39  insn per cycle              ( +-  0.08% )  (66.48%)
        5110756256      branches                         #    1.194 G/sec                       ( +-  0.07% )  (72.03%)
           2719569      branch-misses                    #    0.05% of all branches             ( +-  2.42% )  (72.03%)
                        TopDownL1                 #     0.60 retiring                    ( +-  0.22% )  (66.31%)
                                                  #     0.22 frontend_bound              ( +-  0.21% )  (60.83%)
                                                  #     0.12 bad_speculation             ( +-  0.26% )  (50.25%)
                                                  #     0.06 backend_bound               ( +-  0.17% )  (33.52%)
        8163648527      L1-dcache-loads                  #    1.908 G/sec                       ( +-  0.33% )  (33.52%)
            694979      L1-dcache-load-misses            #    0.01% of all L1-dcache accesses   ( +- 30.53% )  (33.52%)
           1902347      LLC-loads                        #  444.600 K/sec                       ( +- 48.84% )  (33.69%)
             96677      LLC-load-misses                  #    5.08% of all LL-cache accesses    ( +- 43.48% )  (39.30%)
        6863517589      L1-icache-loads                  #    1.604 G/sec                       ( +-  0.37% )  (39.17%)
           1871519      L1-icache-load-misses            #    0.03% of all L1-icache accesses   ( +-  6.78% )  (44.56%)
        8927782813      dTLB-loads                       #    2.087 G/sec                       ( +-  0.14% )  (44.37%)
            438237      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  6.00% )  (49.75%)
        6886906831      iTLB-loads                       #    1.610 G/sec                       ( +-  0.36% )  (55.08%)
             67568      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  3.27% )  (54.86%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

            4.9114 +- 0.0309 seconds time elapsed  ( +-  0.63% )

 Performance counter stats for './test_progs -t flow_dissector' (5 runs):

          10948.40 msec task-clock                       #    0.942 CPUs utilized               ( +-  0.05% )
               615      context-switches                 #   56.173 /sec                        ( +-  1.65% )
                 1      cpu-migrations                   #    0.091 /sec                        ( +- 31.62% )
               567      page-faults                      #   51.788 /sec                        ( +-  0.44% )
       27334194328      cycles                           #    2.497 GHz                         ( +-  0.08% )  (61.05%)
       56656528828      instructions                     #    2.07  insn per cycle              ( +-  0.08% )  (66.67%)
       10270389422      branches                         #  938.072 M/sec                       ( +-  0.10% )  (72.21%)
           3453837      branch-misses                    #    0.03% of all branches             ( +-  3.75% )  (72.27%)
                        TopDownL1                 #     0.52 retiring                    ( +-  0.16% )  (66.55%)
                                                  #     0.27 frontend_bound              ( +-  0.09% )  (60.91%)
                                                  #     0.14 bad_speculation             ( +-  0.08% )  (49.85%)
                                                  #     0.07 backend_bound               ( +-  0.16% )  (33.33%)
       18982866028      L1-dcache-loads                  #    1.734 G/sec                       ( +-  0.24% )  (33.34%)
           8802454      L1-dcache-load-misses            #    0.05% of all L1-dcache accesses   ( +- 52.30% )  (33.31%)
           2612962      LLC-loads                        #  238.661 K/sec                       ( +- 29.78% )  (33.45%)
            264107      LLC-load-misses                  #   10.11% of all LL-cache accesses    ( +- 18.34% )  (39.07%)
       15793205997      L1-icache-loads                  #    1.443 G/sec                       ( +-  0.15% )  (39.09%)
           3930802      L1-icache-load-misses            #    0.02% of all L1-icache accesses   ( +-  3.72% )  (44.66%)
       20097828496      dTLB-loads                       #    1.836 G/sec                       ( +-  0.09% )  (44.68%)
            961757      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  3.32% )  (50.15%)
       15838728506      iTLB-loads                       #    1.447 G/sec                       ( +-  0.09% )  (55.62%)
            167652      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  1.28% )  (55.52%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

           11.6173 +- 0.0268 seconds time elapsed  ( +-  0.23% )

[1] https://lore.kernel.org/bpf/20200724123644.5096-1-maciej.fijalkowski@intel.com/

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 27, 2024
The arm64 jit blindly saves/restores all callee-saved registers, making
the jited result looks a bit too compliated. For example, for an empty
prog, the jited result is:

   0:   bti jc
   4:   mov     x9, lr
   8:   nop
   c:   paciasp
  10:   stp     fp, lr, [sp, #-16]!
  14:   mov     fp, sp
  18:   stp     x19, x20, [sp, #-16]!
  1c:   stp     x21, x22, [sp, #-16]!
  20:   stp     x26, x25, [sp, #-16]!
  24:   mov     x26, #0
  28:   stp     x26, x25, [sp, #-16]!
  2c:   mov     x26, sp
  30:   stp     x27, x28, [sp, #-16]!
  34:   mov     x25, sp
  38:   bti j 		// tailcall target
  3c:   sub     sp, sp, #0
  40:   mov     x7, #0
  44:   add     sp, sp, #0
  48:   ldp     x27, x28, [sp], #16
  4c:   ldp     x26, x25, [sp], #16
  50:   ldp     x26, x25, [sp], #16
  54:   ldp     x21, x22, [sp], #16
  58:   ldp     x19, x20, [sp], #16
  5c:   ldp     fp, lr, [sp], #16
  60:   mov     x0, x7
  64:   autiasp
  68:   ret

Clearly, there is no need to save/restore unused callee-saved registers.
This patch does this change, making the jited image to only save/restore
the callee-saved registers it uses.

Now the jited result of empty prog is:

   0:   bti jc
   4:   mov     x9, lr
   8:   nop
   c:   paciasp
  10:   stp     fp, lr, [sp, #-16]!
  14:   mov     fp, sp
  18:   stp     xzr, x26, [sp, #-16]!
  1c:   mov     x26, sp
  20:   bti j		// tailcall target
  24:   mov     x7, #0
  28:   ldp     xzr, x26, [sp], #16
  2c:   ldp     fp, lr, [sp], #16
  30:   mov     x0, x7
  34:   autiasp
  38:   ret

Since bpf prog saves/restores its own callee-saved registers as needed,
to make tailcall work correctly, the caller needs to restore its saved
registers before tailcall, and the callee needs to save its callee-saved
registers after tailcall. This extra restoring/saving instructions
increases preformance overhead.

[1] provides 2 benchmarks for tailcall scenarios. Below is the perf
number measured in an arm64 KVM guest. The result indicates that the
performance difference before and after the patch in typical tailcall
scenarios is negligible.

- Before:

 Performance counter stats for './test_progs -t tailcalls' (5 runs):

           4313.43 msec task-clock                       #    0.874 CPUs utilized               ( +-  0.16% )
               574      context-switches                 #  133.073 /sec                        ( +-  1.14% )
                 0      cpu-migrations                   #    0.000 /sec
               538      page-faults                      #  124.727 /sec                        ( +-  0.57% )
       10697772784      cycles                           #    2.480 GHz                         ( +-  0.22% )  (61.19%)
       25511241955      instructions                     #    2.38  insn per cycle              ( +-  0.08% )  (66.70%)
        5108910557      branches                         #    1.184 G/sec                       ( +-  0.08% )  (72.38%)
           2800459      branch-misses                    #    0.05% of all branches             ( +-  0.51% )  (72.36%)
                        TopDownL1                 #     0.60 retiring                    ( +-  0.09% )  (66.84%)
                                                  #     0.21 frontend_bound              ( +-  0.15% )  (61.31%)
                                                  #     0.12 bad_speculation             ( +-  0.08% )  (50.11%)
                                                  #     0.07 backend_bound               ( +-  0.16% )  (33.30%)
        8274201819      L1-dcache-loads                  #    1.918 G/sec                       ( +-  0.18% )  (33.15%)
            468268      L1-dcache-load-misses            #    0.01% of all L1-dcache accesses   ( +-  4.69% )  (33.16%)
            385383      LLC-loads                        #   89.345 K/sec                       ( +-  5.22% )  (33.16%)
             38296      LLC-load-misses                  #    9.94% of all LL-cache accesses    ( +- 42.52% )  (38.69%)
        6886576501      L1-icache-loads                  #    1.597 G/sec                       ( +-  0.35% )  (38.69%)
           1848585      L1-icache-load-misses            #    0.03% of all L1-icache accesses   ( +-  4.52% )  (44.23%)
        9043645883      dTLB-loads                       #    2.097 G/sec                       ( +-  0.10% )  (44.33%)
            416672      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  5.15% )  (49.89%)
        6925626111      iTLB-loads                       #    1.606 G/sec                       ( +-  0.35% )  (55.46%)
             66220      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  1.88% )  (55.50%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

            4.9372 +- 0.0526 seconds time elapsed  ( +-  1.07% )

 Performance counter stats for './test_progs -t flow_dissector' (5 runs):

          10924.50 msec task-clock                       #    0.945 CPUs utilized               ( +-  0.08% )
               603      context-switches                 #   55.197 /sec                        ( +-  1.13% )
                 0      cpu-migrations                   #    0.000 /sec
               566      page-faults                      #   51.810 /sec                        ( +-  0.42% )
       27381270695      cycles                           #    2.506 GHz                         ( +-  0.18% )  (60.46%)
       56996583922      instructions                     #    2.08  insn per cycle              ( +-  0.21% )  (66.11%)
       10321647567      branches                         #  944.816 M/sec                       ( +-  0.17% )  (71.79%)
           3347735      branch-misses                    #    0.03% of all branches             ( +-  3.72% )  (72.15%)
                        TopDownL1                 #     0.52 retiring                    ( +-  0.13% )  (66.74%)
                                                  #     0.27 frontend_bound              ( +-  0.14% )  (61.27%)
                                                  #     0.14 bad_speculation             ( +-  0.19% )  (50.36%)
                                                  #     0.07 backend_bound               ( +-  0.42% )  (33.89%)
       18740797617      L1-dcache-loads                  #    1.715 G/sec                       ( +-  0.43% )  (33.71%)
          13715669      L1-dcache-load-misses            #    0.07% of all L1-dcache accesses   ( +- 32.85% )  (33.34%)
           4087551      LLC-loads                        #  374.164 K/sec                       ( +- 29.53% )  (33.26%)
            267906      LLC-load-misses                  #    6.55% of all LL-cache accesses    ( +- 23.90% )  (38.76%)
       15811864229      L1-icache-loads                  #    1.447 G/sec                       ( +-  0.12% )  (38.73%)
           2976833      L1-icache-load-misses            #    0.02% of all L1-icache accesses   ( +-  9.73% )  (44.22%)
       20138907471      dTLB-loads                       #    1.843 G/sec                       ( +-  0.18% )  (44.15%)
            732850      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +- 11.18% )  (49.64%)
       15895726702      iTLB-loads                       #    1.455 G/sec                       ( +-  0.15% )  (55.13%)
            152075      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  4.71% )  (54.98%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

           11.5613 +- 0.0317 seconds time elapsed  ( +-  0.27% )

- After:

 Performance counter stats for './test_progs -t tailcalls' (5 runs):

           4278.78 msec task-clock                       #    0.871 CPUs utilized               ( +-  0.15% )
               569      context-switches                 #  132.982 /sec                        ( +-  0.58% )
                 0      cpu-migrations                   #    0.000 /sec
               539      page-faults                      #  125.970 /sec                        ( +-  0.43% )
       10588986432      cycles                           #    2.475 GHz                         ( +-  0.20% )  (60.91%)
       25303825043      instructions                     #    2.39  insn per cycle              ( +-  0.08% )  (66.48%)
        5110756256      branches                         #    1.194 G/sec                       ( +-  0.07% )  (72.03%)
           2719569      branch-misses                    #    0.05% of all branches             ( +-  2.42% )  (72.03%)
                        TopDownL1                 #     0.60 retiring                    ( +-  0.22% )  (66.31%)
                                                  #     0.22 frontend_bound              ( +-  0.21% )  (60.83%)
                                                  #     0.12 bad_speculation             ( +-  0.26% )  (50.25%)
                                                  #     0.06 backend_bound               ( +-  0.17% )  (33.52%)
        8163648527      L1-dcache-loads                  #    1.908 G/sec                       ( +-  0.33% )  (33.52%)
            694979      L1-dcache-load-misses            #    0.01% of all L1-dcache accesses   ( +- 30.53% )  (33.52%)
           1902347      LLC-loads                        #  444.600 K/sec                       ( +- 48.84% )  (33.69%)
             96677      LLC-load-misses                  #    5.08% of all LL-cache accesses    ( +- 43.48% )  (39.30%)
        6863517589      L1-icache-loads                  #    1.604 G/sec                       ( +-  0.37% )  (39.17%)
           1871519      L1-icache-load-misses            #    0.03% of all L1-icache accesses   ( +-  6.78% )  (44.56%)
        8927782813      dTLB-loads                       #    2.087 G/sec                       ( +-  0.14% )  (44.37%)
            438237      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  6.00% )  (49.75%)
        6886906831      iTLB-loads                       #    1.610 G/sec                       ( +-  0.36% )  (55.08%)
             67568      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  3.27% )  (54.86%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

            4.9114 +- 0.0309 seconds time elapsed  ( +-  0.63% )

 Performance counter stats for './test_progs -t flow_dissector' (5 runs):

          10948.40 msec task-clock                       #    0.942 CPUs utilized               ( +-  0.05% )
               615      context-switches                 #   56.173 /sec                        ( +-  1.65% )
                 1      cpu-migrations                   #    0.091 /sec                        ( +- 31.62% )
               567      page-faults                      #   51.788 /sec                        ( +-  0.44% )
       27334194328      cycles                           #    2.497 GHz                         ( +-  0.08% )  (61.05%)
       56656528828      instructions                     #    2.07  insn per cycle              ( +-  0.08% )  (66.67%)
       10270389422      branches                         #  938.072 M/sec                       ( +-  0.10% )  (72.21%)
           3453837      branch-misses                    #    0.03% of all branches             ( +-  3.75% )  (72.27%)
                        TopDownL1                 #     0.52 retiring                    ( +-  0.16% )  (66.55%)
                                                  #     0.27 frontend_bound              ( +-  0.09% )  (60.91%)
                                                  #     0.14 bad_speculation             ( +-  0.08% )  (49.85%)
                                                  #     0.07 backend_bound               ( +-  0.16% )  (33.33%)
       18982866028      L1-dcache-loads                  #    1.734 G/sec                       ( +-  0.24% )  (33.34%)
           8802454      L1-dcache-load-misses            #    0.05% of all L1-dcache accesses   ( +- 52.30% )  (33.31%)
           2612962      LLC-loads                        #  238.661 K/sec                       ( +- 29.78% )  (33.45%)
            264107      LLC-load-misses                  #   10.11% of all LL-cache accesses    ( +- 18.34% )  (39.07%)
       15793205997      L1-icache-loads                  #    1.443 G/sec                       ( +-  0.15% )  (39.09%)
           3930802      L1-icache-load-misses            #    0.02% of all L1-icache accesses   ( +-  3.72% )  (44.66%)
       20097828496      dTLB-loads                       #    1.836 G/sec                       ( +-  0.09% )  (44.68%)
            961757      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  3.32% )  (50.15%)
       15838728506      iTLB-loads                       #    1.447 G/sec                       ( +-  0.09% )  (55.62%)
            167652      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  1.28% )  (55.52%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

           11.6173 +- 0.0268 seconds time elapsed  ( +-  0.23% )

[1] https://lore.kernel.org/bpf/20200724123644.5096-1-maciej.fijalkowski@intel.com/

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 28, 2024
The arm64 jit blindly saves/restores all callee-saved registers, making
the jited result looks a bit too compliated. For example, for an empty
prog, the jited result is:

   0:   bti jc
   4:   mov     x9, lr
   8:   nop
   c:   paciasp
  10:   stp     fp, lr, [sp, #-16]!
  14:   mov     fp, sp
  18:   stp     x19, x20, [sp, #-16]!
  1c:   stp     x21, x22, [sp, #-16]!
  20:   stp     x26, x25, [sp, #-16]!
  24:   mov     x26, #0
  28:   stp     x26, x25, [sp, #-16]!
  2c:   mov     x26, sp
  30:   stp     x27, x28, [sp, #-16]!
  34:   mov     x25, sp
  38:   bti j 		// tailcall target
  3c:   sub     sp, sp, #0
  40:   mov     x7, #0
  44:   add     sp, sp, #0
  48:   ldp     x27, x28, [sp], #16
  4c:   ldp     x26, x25, [sp], #16
  50:   ldp     x26, x25, [sp], #16
  54:   ldp     x21, x22, [sp], #16
  58:   ldp     x19, x20, [sp], #16
  5c:   ldp     fp, lr, [sp], #16
  60:   mov     x0, x7
  64:   autiasp
  68:   ret

Clearly, there is no need to save/restore unused callee-saved registers.
This patch does this change, making the jited image to only save/restore
the callee-saved registers it uses.

Now the jited result of empty prog is:

   0:   bti jc
   4:   mov     x9, lr
   8:   nop
   c:   paciasp
  10:   stp     fp, lr, [sp, #-16]!
  14:   mov     fp, sp
  18:   stp     xzr, x26, [sp, #-16]!
  1c:   mov     x26, sp
  20:   bti j		// tailcall target
  24:   mov     x7, #0
  28:   ldp     xzr, x26, [sp], #16
  2c:   ldp     fp, lr, [sp], #16
  30:   mov     x0, x7
  34:   autiasp
  38:   ret

Since bpf prog saves/restores its own callee-saved registers as needed,
to make tailcall work correctly, the caller needs to restore its saved
registers before tailcall, and the callee needs to save its callee-saved
registers after tailcall. This extra restoring/saving instructions
increases preformance overhead.

[1] provides 2 benchmarks for tailcall scenarios. Below is the perf
number measured in an arm64 KVM guest. The result indicates that the
performance difference before and after the patch in typical tailcall
scenarios is negligible.

- Before:

 Performance counter stats for './test_progs -t tailcalls' (5 runs):

           4313.43 msec task-clock                       #    0.874 CPUs utilized               ( +-  0.16% )
               574      context-switches                 #  133.073 /sec                        ( +-  1.14% )
                 0      cpu-migrations                   #    0.000 /sec
               538      page-faults                      #  124.727 /sec                        ( +-  0.57% )
       10697772784      cycles                           #    2.480 GHz                         ( +-  0.22% )  (61.19%)
       25511241955      instructions                     #    2.38  insn per cycle              ( +-  0.08% )  (66.70%)
        5108910557      branches                         #    1.184 G/sec                       ( +-  0.08% )  (72.38%)
           2800459      branch-misses                    #    0.05% of all branches             ( +-  0.51% )  (72.36%)
                        TopDownL1                 #     0.60 retiring                    ( +-  0.09% )  (66.84%)
                                                  #     0.21 frontend_bound              ( +-  0.15% )  (61.31%)
                                                  #     0.12 bad_speculation             ( +-  0.08% )  (50.11%)
                                                  #     0.07 backend_bound               ( +-  0.16% )  (33.30%)
        8274201819      L1-dcache-loads                  #    1.918 G/sec                       ( +-  0.18% )  (33.15%)
            468268      L1-dcache-load-misses            #    0.01% of all L1-dcache accesses   ( +-  4.69% )  (33.16%)
            385383      LLC-loads                        #   89.345 K/sec                       ( +-  5.22% )  (33.16%)
             38296      LLC-load-misses                  #    9.94% of all LL-cache accesses    ( +- 42.52% )  (38.69%)
        6886576501      L1-icache-loads                  #    1.597 G/sec                       ( +-  0.35% )  (38.69%)
           1848585      L1-icache-load-misses            #    0.03% of all L1-icache accesses   ( +-  4.52% )  (44.23%)
        9043645883      dTLB-loads                       #    2.097 G/sec                       ( +-  0.10% )  (44.33%)
            416672      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  5.15% )  (49.89%)
        6925626111      iTLB-loads                       #    1.606 G/sec                       ( +-  0.35% )  (55.46%)
             66220      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  1.88% )  (55.50%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

            4.9372 +- 0.0526 seconds time elapsed  ( +-  1.07% )

 Performance counter stats for './test_progs -t flow_dissector' (5 runs):

          10924.50 msec task-clock                       #    0.945 CPUs utilized               ( +-  0.08% )
               603      context-switches                 #   55.197 /sec                        ( +-  1.13% )
                 0      cpu-migrations                   #    0.000 /sec
               566      page-faults                      #   51.810 /sec                        ( +-  0.42% )
       27381270695      cycles                           #    2.506 GHz                         ( +-  0.18% )  (60.46%)
       56996583922      instructions                     #    2.08  insn per cycle              ( +-  0.21% )  (66.11%)
       10321647567      branches                         #  944.816 M/sec                       ( +-  0.17% )  (71.79%)
           3347735      branch-misses                    #    0.03% of all branches             ( +-  3.72% )  (72.15%)
                        TopDownL1                 #     0.52 retiring                    ( +-  0.13% )  (66.74%)
                                                  #     0.27 frontend_bound              ( +-  0.14% )  (61.27%)
                                                  #     0.14 bad_speculation             ( +-  0.19% )  (50.36%)
                                                  #     0.07 backend_bound               ( +-  0.42% )  (33.89%)
       18740797617      L1-dcache-loads                  #    1.715 G/sec                       ( +-  0.43% )  (33.71%)
          13715669      L1-dcache-load-misses            #    0.07% of all L1-dcache accesses   ( +- 32.85% )  (33.34%)
           4087551      LLC-loads                        #  374.164 K/sec                       ( +- 29.53% )  (33.26%)
            267906      LLC-load-misses                  #    6.55% of all LL-cache accesses    ( +- 23.90% )  (38.76%)
       15811864229      L1-icache-loads                  #    1.447 G/sec                       ( +-  0.12% )  (38.73%)
           2976833      L1-icache-load-misses            #    0.02% of all L1-icache accesses   ( +-  9.73% )  (44.22%)
       20138907471      dTLB-loads                       #    1.843 G/sec                       ( +-  0.18% )  (44.15%)
            732850      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +- 11.18% )  (49.64%)
       15895726702      iTLB-loads                       #    1.455 G/sec                       ( +-  0.15% )  (55.13%)
            152075      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  4.71% )  (54.98%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

           11.5613 +- 0.0317 seconds time elapsed  ( +-  0.27% )

- After:

 Performance counter stats for './test_progs -t tailcalls' (5 runs):

           4278.78 msec task-clock                       #    0.871 CPUs utilized               ( +-  0.15% )
               569      context-switches                 #  132.982 /sec                        ( +-  0.58% )
                 0      cpu-migrations                   #    0.000 /sec
               539      page-faults                      #  125.970 /sec                        ( +-  0.43% )
       10588986432      cycles                           #    2.475 GHz                         ( +-  0.20% )  (60.91%)
       25303825043      instructions                     #    2.39  insn per cycle              ( +-  0.08% )  (66.48%)
        5110756256      branches                         #    1.194 G/sec                       ( +-  0.07% )  (72.03%)
           2719569      branch-misses                    #    0.05% of all branches             ( +-  2.42% )  (72.03%)
                        TopDownL1                 #     0.60 retiring                    ( +-  0.22% )  (66.31%)
                                                  #     0.22 frontend_bound              ( +-  0.21% )  (60.83%)
                                                  #     0.12 bad_speculation             ( +-  0.26% )  (50.25%)
                                                  #     0.06 backend_bound               ( +-  0.17% )  (33.52%)
        8163648527      L1-dcache-loads                  #    1.908 G/sec                       ( +-  0.33% )  (33.52%)
            694979      L1-dcache-load-misses            #    0.01% of all L1-dcache accesses   ( +- 30.53% )  (33.52%)
           1902347      LLC-loads                        #  444.600 K/sec                       ( +- 48.84% )  (33.69%)
             96677      LLC-load-misses                  #    5.08% of all LL-cache accesses    ( +- 43.48% )  (39.30%)
        6863517589      L1-icache-loads                  #    1.604 G/sec                       ( +-  0.37% )  (39.17%)
           1871519      L1-icache-load-misses            #    0.03% of all L1-icache accesses   ( +-  6.78% )  (44.56%)
        8927782813      dTLB-loads                       #    2.087 G/sec                       ( +-  0.14% )  (44.37%)
            438237      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  6.00% )  (49.75%)
        6886906831      iTLB-loads                       #    1.610 G/sec                       ( +-  0.36% )  (55.08%)
             67568      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  3.27% )  (54.86%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

            4.9114 +- 0.0309 seconds time elapsed  ( +-  0.63% )

 Performance counter stats for './test_progs -t flow_dissector' (5 runs):

          10948.40 msec task-clock                       #    0.942 CPUs utilized               ( +-  0.05% )
               615      context-switches                 #   56.173 /sec                        ( +-  1.65% )
                 1      cpu-migrations                   #    0.091 /sec                        ( +- 31.62% )
               567      page-faults                      #   51.788 /sec                        ( +-  0.44% )
       27334194328      cycles                           #    2.497 GHz                         ( +-  0.08% )  (61.05%)
       56656528828      instructions                     #    2.07  insn per cycle              ( +-  0.08% )  (66.67%)
       10270389422      branches                         #  938.072 M/sec                       ( +-  0.10% )  (72.21%)
           3453837      branch-misses                    #    0.03% of all branches             ( +-  3.75% )  (72.27%)
                        TopDownL1                 #     0.52 retiring                    ( +-  0.16% )  (66.55%)
                                                  #     0.27 frontend_bound              ( +-  0.09% )  (60.91%)
                                                  #     0.14 bad_speculation             ( +-  0.08% )  (49.85%)
                                                  #     0.07 backend_bound               ( +-  0.16% )  (33.33%)
       18982866028      L1-dcache-loads                  #    1.734 G/sec                       ( +-  0.24% )  (33.34%)
           8802454      L1-dcache-load-misses            #    0.05% of all L1-dcache accesses   ( +- 52.30% )  (33.31%)
           2612962      LLC-loads                        #  238.661 K/sec                       ( +- 29.78% )  (33.45%)
            264107      LLC-load-misses                  #   10.11% of all LL-cache accesses    ( +- 18.34% )  (39.07%)
       15793205997      L1-icache-loads                  #    1.443 G/sec                       ( +-  0.15% )  (39.09%)
           3930802      L1-icache-load-misses            #    0.02% of all L1-icache accesses   ( +-  3.72% )  (44.66%)
       20097828496      dTLB-loads                       #    1.836 G/sec                       ( +-  0.09% )  (44.68%)
            961757      dTLB-load-misses                 #    0.00% of all dTLB cache accesses  ( +-  3.32% )  (50.15%)
       15838728506      iTLB-loads                       #    1.447 G/sec                       ( +-  0.09% )  (55.62%)
            167652      iTLB-load-misses                 #    0.00% of all iTLB cache accesses  ( +-  1.28% )  (55.52%)
   <not supported>      L1-dcache-prefetches
   <not supported>      L1-dcache-prefetch-misses

           11.6173 +- 0.0268 seconds time elapsed  ( +-  0.23% )

[1] https://lore.kernel.org/bpf/20200724123644.5096-1-maciej.fijalkowski@intel.com/

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20240826071624.350108-3-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Aug 28, 2024
Xu Kuohai says:

====================
bpf, arm64: Simplify jited prologue/epilogue

From: Xu Kuohai <xukuohai@huawei.com>

The arm64 jit blindly saves/restores all callee-saved registers, making
the jited result looks a bit too compliated. For example, for an empty
prog, the jited result is:

   0:   bti jc
   4:   mov     x9, lr
   8:   nop
   c:   paciasp
  10:   stp     fp, lr, [sp, #-16]!
  14:   mov     fp, sp
  18:   stp     x19, x20, [sp, #-16]!
  1c:   stp     x21, x22, [sp, #-16]!
  20:   stp     x26, x25, [sp, #-16]!
  24:   mov     x26, #0
  28:   stp     x26, x25, [sp, #-16]!
  2c:   mov     x26, sp
  30:   stp     x27, x28, [sp, #-16]!
  34:   mov     x25, sp
  38:   bti j 		// tailcall target
  3c:   sub     sp, sp, #0
  40:   mov     x7, #0
  44:   add     sp, sp, #0
  48:   ldp     x27, x28, [sp], #16
  4c:   ldp     x26, x25, [sp], #16
  50:   ldp     x26, x25, [sp], #16
  54:   ldp     x21, x22, [sp], #16
  58:   ldp     x19, x20, [sp], #16
  5c:   ldp     fp, lr, [sp], #16
  60:   mov     x0, x7
  64:   autiasp
  68:   ret

Clearly, there is no need to save/restore unused callee-saved registers.
This patch does this change, making the jited image to only save/restore
the callee-saved registers it uses.

Now the jited result of empty prog is:

   0:   bti jc
   4:   mov     x9, lr
   8:   nop
   c:   paciasp
  10:   stp     fp, lr, [sp, #-16]!
  14:   mov     fp, sp
  18:   stp     xzr, x26, [sp, #-16]!
  1c:   mov     x26, sp
  20:   bti j		// tailcall target
  24:   mov     x7, #0
  28:   ldp     xzr, x26, [sp], #16
  2c:   ldp     fp, lr, [sp], #16
  30:   mov     x0, x7
  34:   autiasp
  38:   ret
====================

Acked-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20240826071624.350108-1-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Sep 3, 2024
Currently, BPF_CALL is always jited to indirect call. When target is
within the range of direct call, BPF_CALL can be jited to direct call.

For example, the following BPF_CALL

    call __htab_map_lookup_elem

is always jited to indirect call:

    mov     x10, #0xffffffffffff18f4
    movk    x10, #0x821, lsl #16
    movk    x10, #0x8000, lsl #32
    blr     x10

When the address of target __htab_map_lookup_elem is within the range of
direct call, the BPF_CALL can be jited to:

    bl      0xfffffffffd33bc98

This patch does such jit optimization by emitting arm64 direct calls for
BPF_CALL when possible, indirect calls otherwise.

Without this patch, the jit works as follows.

1. First pass
   A. Determine jited position and size for each bpf instruction.
   B. Computed the jited image size.

2. Allocate jited image with size computed in step 1.

3. Second pass
   A. Adjust jump offset for jump instructions
   B. Write the final image.

This works because, for a given bpf prog, regardless of where the jited
image is allocated, the jited result for each instruction is fixed. The
second pass differs from the first only in adjusting the jump offsets,
like changing "jmp imm1" to "jmp imm2", while the position and size of
the "jmp" instruction remain unchanged.

Now considering whether to jit BPF_CALL to arm64 direct or indirect call
instruction. The choice depends solely on the jump offset: direct call
if the jump offset is within 128MB, indirect call otherwise.

For a given BPF_CALL, the target address is known, so the jump offset is
decided by the jited address of the BPF_CALL instruction. In other words,
for a given bpf prog, the jited result for each BPF_CALL is determined
by its jited address.

The jited address for a BPF_CALL is the jited image address plus the
total jited size of all preceding instructions. For a given bpf prog,
there are clearly no BPF_CALL instructions before the first BPF_CALL
instruction. Since the jited result for all other instructions other
than BPF_CALL are fixed, the total jited size preceding the first
BPF_CALL is also fixed. Therefore, once the jited image is allocated,
the jited address for the first BPF_CALL is fixed.

Now that the jited result for the first BPF_CALL is fixed, the jited
results for all instructions preceding the second BPF_CALL are fixed.
So the jited address and result for the second BPF_CALL are also fixed.

Similarly, we can conclude that the jited addresses and results for all
subsequent BPF_CALL instructions are fixed.

This means that, for a given bpf prog, once the jited image is allocated,
the jited address and result for all instructions, including all BPF_CALL
instructions, are fixed.

Based on the observation, with this patch, the jit works as follows.

1. First pass
   Estimate the maximum jited image size. In this pass, all BPF_CALLs
   are jited to arm64 indirect calls since the jump offsets are unknown
   because the jited image is not allocated.

2. Allocate jited image with size estimated in step 1.

3. Second pass
   A. Determine the jited result for each BPF_CALL.
   B. Determine jited address and size for each bpf instruction.

4. Third pass
   A. Adjust jump offset for jump instructions.
   B. Write the final image.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Sep 4, 2024
Currently, BPF_CALL is always jited to indirect call. When target is
within the range of direct call, BPF_CALL can be jited to direct call.

For example, the following BPF_CALL

    call __htab_map_lookup_elem

is always jited to indirect call:

    mov     x10, #0xffffffffffff18f4
    movk    x10, #0x821, lsl #16
    movk    x10, #0x8000, lsl #32
    blr     x10

When the address of target __htab_map_lookup_elem is within the range of
direct call, the BPF_CALL can be jited to:

    bl      0xfffffffffd33bc98

This patch does such jit optimization by emitting arm64 direct calls for
BPF_CALL when possible, indirect calls otherwise.

Without this patch, the jit works as follows.

1. First pass
   A. Determine jited position and size for each bpf instruction.
   B. Computed the jited image size.

2. Allocate jited image with size computed in step 1.

3. Second pass
   A. Adjust jump offset for jump instructions
   B. Write the final image.

This works because, for a given bpf prog, regardless of where the jited
image is allocated, the jited result for each instruction is fixed. The
second pass differs from the first only in adjusting the jump offsets,
like changing "jmp imm1" to "jmp imm2", while the position and size of
the "jmp" instruction remain unchanged.

Now considering whether to jit BPF_CALL to arm64 direct or indirect call
instruction. The choice depends solely on the jump offset: direct call
if the jump offset is within 128MB, indirect call otherwise.

For a given BPF_CALL, the target address is known, so the jump offset is
decided by the jited address of the BPF_CALL instruction. In other words,
for a given bpf prog, the jited result for each BPF_CALL is determined
by its jited address.

The jited address for a BPF_CALL is the jited image address plus the
total jited size of all preceding instructions. For a given bpf prog,
there are clearly no BPF_CALL instructions before the first BPF_CALL
instruction. Since the jited result for all other instructions other
than BPF_CALL are fixed, the total jited size preceding the first
BPF_CALL is also fixed. Therefore, once the jited image is allocated,
the jited address for the first BPF_CALL is fixed.

Now that the jited result for the first BPF_CALL is fixed, the jited
results for all instructions preceding the second BPF_CALL are fixed.
So the jited address and result for the second BPF_CALL are also fixed.

Similarly, we can conclude that the jited addresses and results for all
subsequent BPF_CALL instructions are fixed.

This means that, for a given bpf prog, once the jited image is allocated,
the jited address and result for all instructions, including all BPF_CALL
instructions, are fixed.

Based on the observation, with this patch, the jit works as follows.

1. First pass
   Estimate the maximum jited image size. In this pass, all BPF_CALLs
   are jited to arm64 indirect calls since the jump offsets are unknown
   because the jited image is not allocated.

2. Allocate jited image with size estimated in step 1.

3. Second pass
   A. Determine the jited result for each BPF_CALL.
   B. Determine jited address and size for each bpf instruction.

4. Third pass
   A. Adjust jump offset for jump instructions.
   B. Write the final image.

Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Reviewed-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20240903094407.601107-1-xukuohai@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Sep 6, 2024
A sysfs reader can race with a device reset or removal, attempting to
read device state when the device is not actually present. eg:

     [exception RIP: qed_get_current_link+17]
  #8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede]
  #9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3
 #10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4
 #11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300
 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c
 #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b
 #14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3
 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1
 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f
 #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb

 crash> struct net_device.state ffff9a9d21336000
    state = 5,

state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100).
The device is not present, note lack of __LINK_STATE_PRESENT (0b10).

This is the same sort of panic as observed in commit 4224cfd
("net-sysfs: add check for netdevice being present to speed_show").

There are many other callers of __ethtool_get_link_ksettings() which
don't have a device presence check.

Move this check into ethtool to protect all callers.

Fixes: d519e17 ("net: export device speed and duplex via sysfs")
Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show")
Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Sep 13, 2024
…rnel/git/netfilter/nf-next

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next:

Patch #1 adds ctnetlink support for kernel side filtering for
	 deletions, from Changliang Wu.

Patch #2 updates nft_counter support to Use u64_stats_t,
	 from Sebastian Andrzej Siewior.

Patch #3 uses kmemdup_array() in all xtables frontends,
	 from Yan Zhen.

Patch #4 is a oneliner to use ERR_CAST() in nf_conntrack instead
	 opencoded casting, from Shen Lichuan.

Patch #5 removes unused argument in nftables .validate interface,
	 from Florian Westphal.

Patch #6 is a oneliner to correct a typo in nftables kdoc,
	 from Simon Horman.

Patch #7 fixes missing kdoc in nftables, also from Simon.

Patch #8 updates nftables to handle timeout less than CONFIG_HZ.

Patch #9 rejects element expiration if timeout is zero,
	 otherwise it is silently ignored.

Patch #10 disallows element expiration larger than timeout.

Patch #11 removes unnecessary READ_ONCE annotation while mutex is held.

Patch #12 adds missing READ_ONCE/WRITE_ONCE annotation in dynset.

Patch #13 annotates data-races around element expiration.

Patch #14 allocates timeout and expiration in one single set element
	  extension, they are tighly couple, no reason to keep them
	  separated anymore.

Patch #15 updates nftables to interpret zero timeout element as never
	  times out. Note that it is already possible to declare sets
	  with elements that never time out but this generalizes to all
	  kind of set with timeouts.

Patch #16 supports for element timeout and expiration updates.

* tag 'nf-next-24-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nf_tables: set element timeout update support
  netfilter: nf_tables: zero timeout means element never times out
  netfilter: nf_tables: consolidate timeout extension for elements
  netfilter: nf_tables: annotate data-races around element expiration
  netfilter: nft_dynset: annotate data-races around set timeout
  netfilter: nf_tables: remove annotation to access set timeout while holding lock
  netfilter: nf_tables: reject expiration higher than timeout
  netfilter: nf_tables: reject element expiration with no timeout
  netfilter: nf_tables: elements with timeout below CONFIG_HZ never expire
  netfilter: nf_tables: Add missing Kernel doc
  netfilter: nf_tables: Correct spelling in nf_tables.h
  netfilter: nf_tables: drop unused 3rd argument from validate callback ops
  netfilter: conntrack: Convert to use ERR_CAST()
  netfilter: Use kmemdup_array instead of kmemdup for multiple allocation
  netfilter: nft_counter: Use u64_stats_t for statistic.
  netfilter: ctnetlink: support CTA_FILTER for flush
====================

Link: https://patch.msgid.link/20240905232920.5481-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Sep 23, 2024
iter_finish_branch_entry() doesn't put the branch_info from/to map
elements creating memory leaks. This can be seen with:

```
$ perf record -e cycles -b perf test -w noploop
$ perf report -D
...
Direct leak of 984344 byte(s) in 123043 object(s) allocated from:
    #0 0x7fb2654f3bd7 in malloc libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x564d3400d10b in map__get util/map.h:186
    #2 0x564d3400d10b in ip__resolve_ams util/machine.c:1981
    #3 0x564d34014d81 in sample__resolve_bstack util/machine.c:2151
    #4 0x564d34094790 in iter_prepare_branch_entry util/hist.c:898
    #5 0x564d34098fa4 in hist_entry_iter__add util/hist.c:1238
    #6 0x564d33d1f0c7 in process_sample_event tools/perf/builtin-report.c:334
    #7 0x564d34031eb7 in perf_session__deliver_event util/session.c:1655
    #8 0x564d3403ba52 in do_flush util/ordered-events.c:245
    #9 0x564d3403ba52 in __ordered_events__flush util/ordered-events.c:324
    #10 0x564d3402d32e in perf_session__process_user_event util/session.c:1708
    #11 0x564d34032480 in perf_session__process_event util/session.c:1877
    #12 0x564d340336ad in reader__read_event util/session.c:2399
    #13 0x564d34033fdc in reader__process_events util/session.c:2448
    #14 0x564d34033fdc in __perf_session__process_events util/session.c:2495
    #15 0x564d34033fdc in perf_session__process_events util/session.c:2661
    #16 0x564d33d27113 in __cmd_report tools/perf/builtin-report.c:1065
    #17 0x564d33d27113 in cmd_report tools/perf/builtin-report.c:1805
    #18 0x564d33e0ccb7 in run_builtin tools/perf/perf.c:350
    #19 0x564d33e0d45e in handle_internal_command tools/perf/perf.c:403
    #20 0x564d33cdd827 in run_argv tools/perf/perf.c:447
    #21 0x564d33cdd827 in main tools/perf/perf.c:561
...
```

Clearing up the map_symbols properly creates maps reference count
issues so resolve those. Resolving this issue doesn't improve peak
heap consumption for the test above.

Committer testing:

  $ sudo dnf install libasan
  $ make -k CORESIGHT=1 EXTRA_CFLAGS="-fsanitize=address" CC=clang O=/tmp/build/$(basename $PWD)/ -C tools/perf install-bin

Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sun Haiyong <sunhaiyong@loongson.cn>
Cc: Yanteng Si <siyanteng@loongson.cn>
Link: https://lore.kernel.org/r/20240807065136.1039977-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Sep 23, 2024
The fields in the hist_entry are filled on-demand which means they only
have meaningful values when relevant sort keys are used.

So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in
the hist entry can be garbage.  So it shouldn't access it
unconditionally.

I got a segfault, when I wanted to see cgroup profiles.

  $ sudo perf record -a --all-cgroups --synth=cgroup true

  $ sudo perf report -s cgroup

  Program received signal SIGSEGV, Segmentation fault.
  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  48		return RC_CHK_ACCESS(map)->dso;
  (gdb) bt
  #0  0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48
  #1  0x00005555557aa39b in map__load (map=0x0) at util/map.c:344
  #2  0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385
  #3  0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true)
      at util/hist.c:644
  #4  0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761
  #5  0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0,
      sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779
  #6  0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015
  #7  0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0)
      at util/hist.c:1260
  #8  0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0,
      machine=0x5555560388e8) at builtin-report.c:334
  #9  0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232
  #10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128,
      sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271
  #11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0,
      file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354
  #12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132
  #13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245
  #14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324
  #15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342
  #16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60)
      at util/session.c:780
  #17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688,
      file_path=0x555556038ff0 "perf.data") at util/session.c:1406

As you can see the entry->ms.map was NULL even if he->ms.map has a
value.  This is because 'sym' sort key is not given, so it cannot assume
whether he->ms.sym and entry->ms.sym is the same.  I only checked the
'sym' sort key here as it implies 'dso' behavior (so maps are the same).

Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Matt Fleming <matt@readmodwrite.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240826221045.1202305-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
kernel-patches-daemon-bpf-rc bot pushed a commit that referenced this pull request Nov 1, 2024
During the migration of Soundwire runtime stream allocation from
the Qualcomm Soundwire controller to SoC's soundcard drivers the sdm845
soundcard was forgotten.

At this point any playback attempt or audio daemon startup, for instance
on sdm845-db845c (Qualcomm RB3 board), will result in stream pointer
NULL dereference:

 Unable to handle kernel NULL pointer dereference at virtual
 address 0000000000000020
 Mem abort info:
   ESR = 0x0000000096000004
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x04: level 0 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=0000000101ecf000
 [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
 Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
 Modules linked in: ...
 CPU: 5 UID: 0 PID: 1198 Comm: aplay
 Not tainted 6.12.0-rc2-qcomlt-arm64-00059-g9d78f315a362-dirty #18
 Hardware name: Thundercomm Dragonboard 845c (DT)
 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : sdw_stream_add_slave+0x44/0x380 [soundwire_bus]
 lr : sdw_stream_add_slave+0x44/0x380 [soundwire_bus]
 sp : ffff80008a2035c0
 x29: ffff80008a2035c0 x28: ffff80008a203978 x27: 0000000000000000
 x26: 00000000000000c0 x25: 0000000000000000 x24: ffff1676025f4800
 x23: ffff167600ff1cb8 x22: ffff167600ff1c98 x21: 0000000000000003
 x20: ffff167607316000 x19: ffff167604e64e80 x18: 0000000000000000
 x17: 0000000000000000 x16: ffffcec265074160 x15: 0000000000000000
 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffff167600ff1cec
 x5 : ffffcec22cfa2010 x4 : 0000000000000000 x3 : 0000000000000003
 x2 : ffff167613f836c0 x1 : 0000000000000000 x0 : ffff16761feb60b8
 Call trace:
  sdw_stream_add_slave+0x44/0x380 [soundwire_bus]
  wsa881x_hw_params+0x68/0x80 [snd_soc_wsa881x]
  snd_soc_dai_hw_params+0x3c/0xa4
  __soc_pcm_hw_params+0x230/0x660
  dpcm_be_dai_hw_params+0x1d0/0x3f8
  dpcm_fe_dai_hw_params+0x98/0x268
  snd_pcm_hw_params+0x124/0x460
  snd_pcm_common_ioctl+0x998/0x16e8
  snd_pcm_ioctl+0x34/0x58
  __arm64_sys_ioctl+0xac/0xf8
  invoke_syscall+0x48/0x104
  el0_svc_common.constprop.0+0x40/0xe0
  do_el0_svc+0x1c/0x28
  el0_svc+0x34/0xe0
  el0t_64_sync_handler+0x120/0x12c
  el0t_64_sync+0x190/0x194
 Code: aa0403fb f9418400 9100e000 9400102f (f8420f22)
 ---[ end trace 0000000000000000 ]---

0000000000006108 <sdw_stream_add_slave>:
    6108:       d503233f        paciasp
    610c:       a9b97bfd        stp     x29, x30, [sp, #-112]!
    6110:       910003fd        mov     x29, sp
    6114:       a90153f3        stp     x19, x20, [sp, #16]
    6118:       a9025bf5        stp     x21, x22, [sp, #32]
    611c:       aa0103f6        mov     x22, x1
    6120:       2a0303f5        mov     w21, w3
    6124:       a90363f7        stp     x23, x24, [sp, #48]
    6128:       aa0003f8        mov     x24, x0
    612c:       aa0203f7        mov     x23, x2
    6130:       a9046bf9        stp     x25, x26, [sp, #64]
    6134:       aa0403f9        mov     x25, x4        <-- x4 copied to x25
    6138:       a90573fb        stp     x27, x28, [sp, #80]
    613c:       aa0403fb        mov     x27, x4
    6140:       f9418400        ldr     x0, [x0, #776]
    6144:       9100e000        add     x0, x0, #0x38
    6148:       94000000        bl      0 <mutex_lock>
    614c:       f8420f22        ldr     x2, [x25, #32]!  <-- offset 0x44
    ^^^
This is 0x6108 + offset 0x44 from the beginning of sdw_stream_add_slave()
where data abort happens.
wsa881x_hw_params() is called with stream = NULL and passes it further
in register x4 (5th argument) to sdw_stream_add_slave() without any checks.
Value from x4 is copied to x25 and finally it aborts on trying to load
a value from address in x25 plus offset 32 (in dec) which corresponds
to master_list member in struct sdw_stream_runtime:

struct sdw_stream_runtime {
        const char  *              name;	/*     0     8 */
        struct sdw_stream_params   params;	/*     8    12 */
        enum sdw_stream_state      state;	/*    20     4 */
        enum sdw_stream_type       type;	/*    24     4 */
        /* XXX 4 bytes hole, try to pack */
 here-> struct list_head           master_list;	/*    32    16 */
        int                        m_rt_count;	/*    48     4 */
        /* size: 56, cachelines: 1, members: 6 */
        /* sum members: 48, holes: 1, sum holes: 4 */
        /* padding: 4 */
        /* last cacheline: 56 bytes */

Fix this by adding required calls to qcom_snd_sdw_startup() and
sdw_release_stream() to startup and shutdown routines which restores
the previous correct behaviour when ->set_stream() method is called to
set a valid stream runtime pointer on playback startup.

Reproduced and then fix was tested on db845c RB3 board.

Reported-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: stable@vger.kernel.org
Fixes: 15c7fab ("ASoC: qcom: Move Soundwire runtime stream alloc to soundcards")
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
Tested-by: Steev Klimaszewski <steev@kali.org> # Lenovo Yoga C630
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://patch.msgid.link/20241009213922.999355-1-alexey.klimov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
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