3.14-rc3 #72

shanmin · 2014-02-21T01:54:49Z

No description provided.

update

Turn it into (for example): [ 0.073380] x86: Booting SMP configuration: [ 0.074005] .... node #0, CPUs: #1 #2 #3 #4 #5 torvalds#6 torvalds#7 [ 0.603005] .... node #1, CPUs: torvalds#8 torvalds#9 torvalds#10 torvalds#11 torvalds#12 torvalds#13 torvalds#14 torvalds#15 [ 1.200005] .... node #2, CPUs: torvalds#16 torvalds#17 torvalds#18 torvalds#19 torvalds#20 torvalds#21 torvalds#22 torvalds#23 [ 1.796005] .... node #3, CPUs: torvalds#24 torvalds#25 torvalds#26 torvalds#27 torvalds#28 torvalds#29 torvalds#30 torvalds#31 [ 2.393005] .... node #4, CPUs: torvalds#32 torvalds#33 torvalds#34 torvalds#35 torvalds#36 torvalds#37 torvalds#38 torvalds#39 [ 2.996005] .... node #5, CPUs: torvalds#40 torvalds#41 torvalds#42 torvalds#43 torvalds#44 torvalds#45 torvalds#46 torvalds#47 [ 3.600005] .... node torvalds#6, CPUs: torvalds#48 torvalds#49 torvalds#50 torvalds#51 #52 #53 torvalds#54 torvalds#55 [ 4.202005] .... node torvalds#7, CPUs: torvalds#56 torvalds#57 #58 torvalds#59 torvalds#60 torvalds#61 torvalds#62 torvalds#63 [ 4.811005] .... node torvalds#8, CPUs: torvalds#64 torvalds#65 torvalds#66 torvalds#67 torvalds#68 torvalds#69 #70 torvalds#71 [ 5.421006] .... node torvalds#9, CPUs: torvalds#72 torvalds#73 torvalds#74 torvalds#75 torvalds#76 torvalds#77 torvalds#78 torvalds#79 [ 6.032005] .... node torvalds#10, CPUs: torvalds#80 torvalds#81 torvalds#82 torvalds#83 torvalds#84 torvalds#85 torvalds#86 torvalds#87 [ 6.648006] .... node torvalds#11, CPUs: torvalds#88 torvalds#89 torvalds#90 torvalds#91 torvalds#92 torvalds#93 torvalds#94 torvalds#95 [ 7.262005] .... node torvalds#12, CPUs: torvalds#96 torvalds#97 torvalds#98 torvalds#99 torvalds#100 torvalds#101 torvalds#102 torvalds#103 [ 7.865005] .... node torvalds#13, CPUs: torvalds#104 torvalds#105 torvalds#106 torvalds#107 torvalds#108 torvalds#109 torvalds#110 torvalds#111 [ 8.466005] .... node torvalds#14, CPUs: torvalds#112 torvalds#113 torvalds#114 torvalds#115 torvalds#116 torvalds#117 torvalds#118 torvalds#119 [ 9.073006] .... node torvalds#15, CPUs: torvalds#120 torvalds#121 torvalds#122 torvalds#123 torvalds#124 torvalds#125 torvalds#126 torvalds#127 [ 9.679901] x86: Booted up 16 nodes, 128 CPUs and drop useless elements. Change num_digits() to hpa's division-avoiding, cell-phone-typed version which he went at great lengths and pains to submit on a Saturday evening. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: huawei.libin@huawei.com Cc: wangyijing@huawei.com Cc: fenghua.yu@intel.com Cc: guohanjun@huawei.com Cc: paul.gortmaker@windriver.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20130930095624.GB16383@pd.tnic Signed-off-by: Ingo Molnar <mingo@kernel.org>

pci_get_slot() is called with hold of PCI bus semaphore and it's not safe to be called in interrupt context. However, we possibly checks EEH error and calls the function in interrupt context. To avoid using pci_get_slot(), we turn into device tree for fetching location code. Otherwise, we might run into WARN_ON() as following messages indicate: WARNING: at drivers/pci/search.c:223 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc3+ torvalds#72 task: c000000001367af0 ti: c000000001444000 task.ti: c000000001444000 NIP: c000000000497b70 LR: c000000000037530 CTR: 000000003003d114 REGS: c000000001446fa0 TRAP: 0700 Not tainted (3.16.0-rc3+) MSR: 9000000000029032 <SF,HV,EE,ME,IR,DR,RI> CR: 48002422 XER: 20000000 CFAR: c00000000003752c SOFTE: 0 : NIP [c000000000497b70] .pci_get_slot+0x40/0x110 LR [c000000000037530] .eeh_pe_loc_get+0x150/0x190 Call Trace: .of_get_property+0x30/0x60 (unreliable) .eeh_pe_loc_get+0x150/0x190 .eeh_dev_check_failure+0x1b4/0x550 .eeh_check_failure+0x90/0xf0 .lpfc_sli_check_eratt+0x504/0x7c0 [lpfc] .lpfc_poll_eratt+0x64/0x100 [lpfc] .call_timer_fn+0x64/0x190 .run_timer_softirq+0x2cc/0x3e0 Cc: stable@vger.kernel.org Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

commit 9e5c6e5 upstream. pci_get_slot() is called with hold of PCI bus semaphore and it's not safe to be called in interrupt context. However, we possibly checks EEH error and calls the function in interrupt context. To avoid using pci_get_slot(), we turn into device tree for fetching location code. Otherwise, we might run into WARN_ON() as following messages indicate: WARNING: at drivers/pci/search.c:223 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-rc3+ #72 task: c000000001367af0 ti: c000000001444000 task.ti: c000000001444000 NIP: c000000000497b70 LR: c000000000037530 CTR: 000000003003d114 REGS: c000000001446fa0 TRAP: 0700 Not tainted (3.16.0-rc3+) MSR: 9000000000029032 <SF,HV,EE,ME,IR,DR,RI> CR: 48002422 XER: 20000000 CFAR: c00000000003752c SOFTE: 0 : NIP [c000000000497b70] .pci_get_slot+0x40/0x110 LR [c000000000037530] .eeh_pe_loc_get+0x150/0x190 Call Trace: .of_get_property+0x30/0x60 (unreliable) .eeh_pe_loc_get+0x150/0x190 .eeh_dev_check_failure+0x1b4/0x550 .eeh_check_failure+0x90/0xf0 .lpfc_sli_check_eratt+0x504/0x7c0 [lpfc] .lpfc_poll_eratt+0x64/0x100 [lpfc] .call_timer_fn+0x64/0x190 .run_timer_softirq+0x2cc/0x3e0 Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Suspicious RCU usage in qdisc_watchdog call needs to be done inside rcu_read_lock/rcu_read_unlock. And then Qdisc destroy operations need to ensure timer is cancelled before removing qdisc structure. [ 3992.191339] =============================== [ 3992.191340] [ INFO: suspicious RCU usage. ] [ 3992.191343] 3.17.0-rc6net-next+ torvalds#72 Not tainted [ 3992.191345] ------------------------------- [ 3992.191347] include/net/sch_generic.h:272 suspicious rcu_dereference_check() usage! [ 3992.191348] [ 3992.191348] other info that might help us debug this: [ 3992.191348] [ 3992.191351] [ 3992.191351] rcu_scheduler_active = 1, debug_locks = 1 [ 3992.191353] no locks held by swapper/1/0. [ 3992.191355] [ 3992.191355] stack backtrace: [ 3992.191358] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.17.0-rc6net-next+ torvalds#72 [ 3992.191360] Hardware name: /DZ77RE-75K, BIOS GAZ7711H.86A.0060.2012.1115.1750 11/15/2012 [ 3992.191362] 0000000000000001 ffff880235803e48 ffffffff8178f92c 0000000000000000 [ 3992.191366] ffff8802322224a0 ffff880235803e78 ffffffff810c9966 ffff8800a5fe3000 [ 3992.191370] ffff880235803f30 ffff8802359cd768 ffff8802359cd6e0 ffff880235803e98 [ 3992.191374] Call Trace: [ 3992.191376] <IRQ> [<ffffffff8178f92c>] dump_stack+0x4e/0x68 [ 3992.191387] [<ffffffff810c9966>] lockdep_rcu_suspicious+0xe6/0x130 [ 3992.191392] [<ffffffff8167213a>] qdisc_watchdog+0x8a/0xb0 [ 3992.191396] [<ffffffff810f93f2>] __run_hrtimer+0x72/0x420 [ 3992.191399] [<ffffffff810f9bcd>] ? hrtimer_interrupt+0x7d/0x240 [ 3992.191403] [<ffffffff816720b0>] ? tc_classify+0xc0/0xc0 [ 3992.191406] [<ffffffff810f9c4f>] hrtimer_interrupt+0xff/0x240 [ 3992.191410] [<ffffffff8109e4a5>] ? __atomic_notifier_call_chain+0x5/0x140 [ 3992.191415] [<ffffffff8103577b>] local_apic_timer_interrupt+0x3b/0x60 [ 3992.191419] [<ffffffff8179c2b5>] smp_apic_timer_interrupt+0x45/0x60 [ 3992.191422] [<ffffffff8179a6bf>] apic_timer_interrupt+0x6f/0x80 [ 3992.191424] <EOI> [<ffffffff815ed233>] ? cpuidle_enter_state+0x73/0x2e0 [ 3992.191432] [<ffffffff815ed22e>] ? cpuidle_enter_state+0x6e/0x2e0 [ 3992.191437] [<ffffffff815ed567>] cpuidle_enter+0x17/0x20 [ 3992.191441] [<ffffffff810c0741>] cpu_startup_entry+0x3d1/0x4a0 [ 3992.191445] [<ffffffff81106fc6>] ? clockevents_config_and_register+0x26/0x30 [ 3992.191448] [<ffffffff81033c16>] start_secondary+0x1b6/0x260 Fixes: b26b0d1 ("net: qdisc: use rcu prefix and silence sparse warnings") Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Acked-by: Cong Wang <cwang@twopensource.com> Signed-off-by: David S. Miller <davem@davemloft.net>

Add UHID config for BT mouse

Fix compilation error for kernel version codes < 3.0.0

objdump's raw insn output can vary across architectures on number of bytes per chunk (bpc) displayed and their endian. code-reading test relied on reading objdump output as 1 bpc. Kaixu Xia reported test failure on ARM64, where objdump displays 4 bpc: 70c48: f90027bf str xzr, [x29,torvalds#72] 70c4c: 91224000 add x0, x0, #0x890 70c50: f90023a0 str x0, [x29,torvalds#64] This patch adds support to read raw insn output for any bpc length. In case of 2+ bpc it also guesses objdump's display endian. Signed-off-by: Jan Stancek <jstancek@redhat.com> Reported-and-tested-by: Kaixu Xia <xiakaixu@huawei.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>

…chg_inatomic() The futex subsystem relies on futex_atomic_cmpxchg_inatomic() to perform an atomic cmpxchg. Most architectures provide their own implementation. For those who do not, <asm-generic/futex.h> provides a generic software implementations that works on !SMP platforms. To provide an atomicity guarantee on !SMP plaforms, the generic implementation simply disables preemption. However it is not properly re-enabled from conditional branches. The observed consequence of this bug is that the preemption counter is not well balanced. It can be seen at boot time : [ 8.148000] futex hash table entries: 256 (order: -1, 3072 bytes) [ 8.156000] ------------[ cut here ]------------ [ 8.164000] WARNING: CPU: 0 PID: 1 at init/main.c:806 do_one_initcall+0x1ac/0x1d0() [ 8.172000] initcall futex_init+0x0/0xd8 returned with preemption imbalance [ 8.180000] Modules linked in: [ 8.184000] CPU: 0 PID: 1 Comm: swapper Not tainted 4.5.0 torvalds#72 [ 8.192000] Stack from d1c1deb8: [ 8.196000] [ 8.196000] d1c1debc [ 8.204000] d1c1defc 00000009 [ 8.204000] d04d8b90 00000326 [ 8.208000] d0000380 d0136484 [ 8.212000] d00093b4 [ 8.216000] 00000326 d0000380 [ 8.220000] d1c1c000 00000000 [ 8.224000] d026c64c 00000000 [ 8.228000] d0515004 d0009410 [ 8.232000] [ 8.232000] d1c1defc [ 8.236000] d04d8d8c d1c1df08 [ 8.240000] d0000380 d026c64c [ 8.244000] d1c1df10 65657270 [ 8.248000] 6974706d [ 8.252000] 69206e6f 6c61626d [ 8.256000] 65636e61 d0780020 [ 8.260000] d05108a0 00000001 [ 8.264000] d00225c8 00000000 [ 8.268000] [ 8.268000] d05103c8 [ 8.272000] 0000003f 00060006 [ 8.276000] d05108a0 00000006 [ 8.280000] 0000003f 00000007 [ 8.284000] 0000003f [ 8.288000] d052501 d0525024 [ 8.288000] d027d480 d0266c78 [ 8.292000] 00000006 00000006 [ 8.296000] 00000000 d026627c [ 8.300000] [ 8.300000] Call Trace: [ 8.308000] [<d025fc58>] [<d025fc68>] [ 8.312000] [<d025fc58>] [<d000130c>] [ 8.316000] [ 8.316000] ---[ end trace 2d3fe47ac46f91f6 ]--- Before commit 8222dbe ("sched/preempt, mm/fault: Decouple preemption from the page fault logic") , the preemption was disabled/re-enabled by the pagefault_disable()/pagefault_enable() functions. It is no longer the case. Which means that cmpxchg_futex_value_locked(), in kernel/futex.c, no longer disables preemption before calling futex_atomic_cmpxchg_inatomic. Disabling preemption in the generic implementation was added by commit d9b9ff8 ("sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly"). However, this change is bogus: preemption is not re-enabled in the two failure cases. Indeed, At boot time futex_detect_cmpxchg(), in kernel/futex.c, checks if futex_atomic_cmpxchg_inatomic() operation is provided by the current architecture. To do so, it calls futex_atomic_cmpxchg_inatomic() with a NULL pointer as the futex, and expects -EFAULT as a return value. The reasoning if that if -EFAULT is returned, then there is a valid futex_atomic_cmpxchg_inatomic() implementation, while if -ENOSYS is returned, then it means that there is no implementation of this function for the current architecture. By doing this test based on a NULL pointer, we fall into the case where the get_user() in the asm-generic version of futex_atomic_cmpxchg_inatomic() fails, and returns -EFAULT without re-enabling the preemption, causing the preemption unbalance in the futex_init() initcall. This bug was not found, because most of the architectures in the kernel use their own implementation. This is not the case for the nios2 platform. By using a nios2 board without SMP support, this bug can be easily reproduced. Fixes: d9b9ff8 ("sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly") Signed-off-by: Romain Perier <romain.perier@free-electrons.com>

objdump's raw insn output can vary across architectures on the number of bytes per chunk (bpc) displayed and their endianness. The code-reading test relied on reading objdump output as 1 bpc. Kaixu Xia reported test failure on ARM64, where objdump displays 4 bpc: 70c48: f90027bf str xzr, [x29,torvalds#72] 70c4c: 91224000 add x0, x0, #0x890 70c50: f90023a0 str x0, [x29,torvalds#64] This patch adds support to read raw insn output for any bpc length. In case of 2+ bpc it also guesses objdump's display endian. Reported-and-Tested-by: Kaixu Xia <xiakaixu@huawei.com> Signed-off-by: Jan Stancek <jstancek@redhat.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/07f0f7bcbda78deb423298708ef9b6a54d6b92bd.1452592712.git.jstancek@redhat.com [ Fix up pr_fmt() call to use %zd for size_t variables, fixing the build on Ubuntu cross-compiling to armhf and ppc64 ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

On lubbock board, the probe of the driver crashes by dereferencing very early a platform_data structure which is not set, in pxa2xx_configure_sockets(). The stack fixed is : [ 0.244353] SA1111 Microprocessor Companion Chip: silicon revision 1, metal revision 1 [ 0.256321] sa1111 sa1111: Providing IRQ336-390 [ 0.340899] clocksource: Switched to clocksource oscr0 [ 0.472263] Unable to handle kernel NULL pointer dereference at virtual address 00000004 [ 0.480469] pgd = c0004000 [ 0.483432] [00000004] *pgd=00000000 [ 0.487105] Internal error: Oops: f5 [#1] ARM [ 0.491497] Modules linked in: [ 0.494650] CPU: 0 PID: 1 Comm: swapper Not tainted 4.8.0-rc3-00080-g1aaa68426f0c-dirty #2068 [ 0.503229] Hardware name: Intel DBPXA250 Development Platform (aka Lubbock) [ 0.510344] task: c3e42000 task.stack: c3e44000 [ 0.514984] PC is at pxa2xx_configure_sockets+0x4/0x24 (drivers/pcmcia/pxa2xx_base.c:227) [ 0.520193] LR is at pcmcia_lubbock_init+0x1c/0x38 [ 0.525079] pc : [<c0247c30>] lr : [<c02479b0>] psr: a0000053 [ 0.525079] sp : c3e45e70 ip : 100019ff fp : 00000000 [ 0.536651] r10: c0828900 r9 : c0434838 r8 : 00000000 [ 0.541953] r7 : c0820700 r6 : c0857b30 r5 : c3ec1400 r4 : c0820758 [ 0.548549] r3 : 00000000 r2 : 0000000c r1 : c3c09c40 r0 : c3ec1400 [ 0.555154] Flags: NzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment none [ 0.562450] Control: 0000397f Table: a0004000 DAC: 00000053 [ 0.568257] Process swapper (pid: 1, stack limit = 0xc3e44190) [ 0.574154] Stack: (0xc3e45e70 to 0xc3e46000) [ 0.578610] 5e60: c4849800 00000000 c3ec1400 c024769c [ 0.586928] 5e80: 00000000 c3ec140c c3c0ee0c c3ec1400 c3ec1434 c020c410 c3ec1400 c3ec1434 [ 0.595244] 5ea0: c0820700 c080b408 c0828900 c020c5f8 00000000 c0820700 c020c578 c020ac5c [ 0.603560] 5ec0: c3e687cc c3e71e10 c0820700 00000000 c3c02de0 c020bae4 c03c62f7 c03c62f7 [ 0.611872] 5ee0: c3e68780 c0820700 c042e034 00000000 c043c440 c020cdec c080b408 00000005 [ 0.620188] 5f00: c042e034 c00096c0 c0034440 c01c730c 20000053 ffffffff 00000000 00000000 [ 0.628502] 5f20: 00000000 c3ffcb87 c3ffcb90 c00346ac c3e66ba0 c03f7914 00000092 00000005 [ 0.636811] 5f40: 00000005 c03f847c 00000091 c03f847c 00000000 00000005 c0434828 00000005 [ 0.645125] 5f60: c043482c 00000092 c043c440 c0828900 c0434838 c0418d2c 00000005 00000005 [ 0.653430] 5f80: 00000000 c041858c 00000000 c032e9f0 00000000 00000000 00000000 00000000 [ 0.661729] 5fa0: 00000000 c032e9f8 00000000 c000f0f0 00000000 00000000 00000000 00000000 [ 0.670020] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 0.678311] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [ 0.686673] (pxa2xx_configure_sockets) from pcmcia_lubbock_init (/drivers/pcmcia/sa1111_lubbock.c:161) [ 0.696026] (pcmcia_lubbock_init) from pcmcia_probe (/drivers/pcmcia/sa1111_generic.c:213) [ 0.704358] (pcmcia_probe) from driver_probe_device (/drivers/base/dd.c:378 /drivers/base/dd.c:499) [ 0.712848] (driver_probe_device) from __driver_attach (/./include/linux/device.h:983 /drivers/base/dd.c:733) [ 0.721414] (__driver_attach) from bus_for_each_dev (/drivers/base/bus.c:313) [ 0.729723] (bus_for_each_dev) from bus_add_driver (/drivers/base/bus.c:708) [ 0.738036] (bus_add_driver) from driver_register (/drivers/base/driver.c:169) [ 0.746185] (driver_register) from do_one_initcall (/init/main.c:778) [ 0.754561] (do_one_initcall) from kernel_init_freeable (/init/main.c:843 /init/main.c:851 /init/main.c:869 /init/main.c:1016) [ 0.763409] (kernel_init_freeable) from kernel_init (/init/main.c:944) [ 0.771660] (kernel_init) from ret_from_fork (/arch/arm/kernel/entry-common.S:119) [ 0.779347] Code: c03c6305 c03c631e c03c632e e5903048 (e993000c) All code ======== 0: c03c6305 eorsgt r6, ip, r5, lsl torvalds#6 4: c03c631e eorsgt r6, ip, lr, lsl r3 8: c03c632e eorsgt r6, ip, lr, lsr torvalds#6 c: e5903048 ldr r3, [r0, torvalds#72] ; 0x48 10:* e993000c ldmib r3, {r2, r3} <-- trapping instruction Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

When dev replace is cancelled by running scrub, we will free target device without waiting flighting bios, causing the following NULL pointer deference or general protection. BUG: unable to handle kernel NULL pointer dereference at 00000000000005e0 IP: generic_make_request_checks+0x4d/0x610 CPU: 1 PID: 11676 Comm: kworker/u4:14 Tainted: G O 4.11.0-rc2 torvalds#72 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-20170228_101828-anatol 04/01/2014 Workqueue: btrfs-endio-raid56 btrfs_endio_raid56_helper [btrfs] task: ffff88002875b4c0 task.stack: ffffc90001334000 RIP: 0010:generic_make_request_checks+0x4d/0x610 Call Trace: ? generic_make_request+0xc7/0x360 generic_make_request+0x24/0x360 ? generic_make_request+0xc7/0x360 submit_bio+0x64/0x120 ? page_in_rbio+0x4d/0x80 [btrfs] ? rbio_orig_end_io+0x80/0x80 [btrfs] finish_rmw+0x3f4/0x540 [btrfs] validate_rbio_for_rmw+0x36/0x40 [btrfs] raid_rmw_end_io+0x7a/0x90 [btrfs] bio_endio+0x56/0x60 end_workqueue_fn+0x3c/0x40 [btrfs] btrfs_scrubparity_helper+0xef/0x620 [btrfs] btrfs_endio_raid56_helper+0xe/0x10 [btrfs] process_one_work+0x2af/0x720 ? process_one_work+0x22b/0x720 worker_thread+0x4b/0x4f0 kthread+0x10f/0x150 ? process_one_work+0x720/0x720 ? kthread_create_on_node+0x40/0x40 ret_from_fork+0x2e/0x40 Code: 67 28 48 c7 c7 27 7f c9 81 e8 90 6c d4 ff e8 0b bb 54 00 41 c1 ec 09 48 8b 7b 08 45 85 e4 0f 85 be 00 00 00 48 8b 87 00 01 00 00 <4c> 8b b0 e0 05 00 00 4d 85 f6 0f 84 86 01 00 00 4c 8b af f0 00 RIP: generic_make_request_checks+0x4d/0x610 RSP: ffffc90001337bb8 In btrfs_dev_replace_finishing(), we will call btrfs_rm_dev_replace_blocked() to wait bios before destroying the target device when scrub is finished normally. However when scrub is aborted, either due to error or canceled by scrub, we didn't wait bios, this can leads to use-after-free if there are bios holding the target device. Fix it by also calling btrfs_rm_dev_replace_blocked() before calling btrfs_destroy_dev_replace_tgtdev(). Cc: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>

[ Upstream commit 3004081 ] In case runtime PM is enabled, do runtime PM clean up to remove cpu latency qos request, otherwise driver removal may have below kernel dump: [ 19.463299] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000048 [ 19.472161] Mem abort info: [ 19.474985] ESR = 0x0000000096000004 [ 19.478754] EC = 0x25: DABT (current EL), IL = 32 bits [ 19.484081] SET = 0, FnV = 0 [ 19.487149] EA = 0, S1PTW = 0 [ 19.490361] FSC = 0x04: level 0 translation fault [ 19.495256] Data abort info: [ 19.498149] ISV = 0, ISS = 0x00000004 [ 19.501997] CM = 0, WnR = 0 [ 19.504977] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000049f81000 [ 19.511432] [0000000000000048] pgd=0000000000000000, p4d=0000000000000000 [ 19.518245] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 19.524520] Modules linked in: gpio_ir_recv(+) rc_core [last unloaded: rc_core] [ 19.531845] CPU: 0 PID: 445 Comm: insmod Not tainted 6.2.0-rc1-00028-g2c397a46d47c torvalds#72 [ 19.531854] Hardware name: FSL i.MX8MM EVK board (DT) [ 19.531859] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 19.551777] pc : cpu_latency_qos_remove_request+0x20/0x110 [ 19.557277] lr : gpio_ir_recv_runtime_suspend+0x18/0x30 [gpio_ir_recv] [ 19.557294] sp : ffff800008ce3740 [ 19.557297] x29: ffff800008ce3740 x28: 0000000000000000 x27: ffff800008ce3d50 [ 19.574270] x26: ffffc7e3e9cea100 x25: 00000000000f4240 x24: ffffc7e3f9ef0e30 [ 19.574284] x23: 0000000000000000 x22: ffff0061803820f4 x21: 0000000000000008 [ 19.574296] x20: ffffc7e3fa75df30 x19: 0000000000000020 x18: ffffffffffffffff [ 19.588570] x17: 0000000000000000 x16: ffffc7e3f9efab70 x15: ffffffffffffffff [ 19.595712] x14: ffff800008ce37b8 x13: ffff800008ce37aa x12: 0000000000000001 [ 19.602853] x11: 0000000000000001 x10: ffffcbe3ec0dff87 x9 : 0000000000000008 [ 19.609991] x8 : 0101010101010101 x7 : 0000000000000000 x6 : 000000000f0bfe9f [ 19.624261] x5 : 00ffffffffffffff x4 : 0025ab8e00000000 x3 : ffff006180382010 [ 19.631405] x2 : ffffc7e3e9ce8030 x1 : ffffc7e3fc3eb810 x0 : 0000000000000020 [ 19.638548] Call trace: [ 19.640995] cpu_latency_qos_remove_request+0x20/0x110 [ 19.646142] gpio_ir_recv_runtime_suspend+0x18/0x30 [gpio_ir_recv] [ 19.652339] pm_generic_runtime_suspend+0x2c/0x44 [ 19.657055] __rpm_callback+0x48/0x1dc [ 19.660807] rpm_callback+0x6c/0x80 [ 19.664301] rpm_suspend+0x10c/0x640 [ 19.667880] rpm_idle+0x250/0x2d0 [ 19.671198] update_autosuspend+0x38/0xe0 [ 19.675213] pm_runtime_set_autosuspend_delay+0x40/0x60 [ 19.680442] gpio_ir_recv_probe+0x1b4/0x21c [gpio_ir_recv] [ 19.685941] platform_probe+0x68/0xc0 [ 19.689610] really_probe+0xc0/0x3dc [ 19.693189] __driver_probe_device+0x7c/0x190 [ 19.697550] driver_probe_device+0x3c/0x110 [ 19.701739] __driver_attach+0xf4/0x200 [ 19.705578] bus_for_each_dev+0x70/0xd0 [ 19.709417] driver_attach+0x24/0x30 [ 19.712998] bus_add_driver+0x17c/0x240 [ 19.716834] driver_register+0x78/0x130 [ 19.720676] __platform_driver_register+0x28/0x34 [ 19.725386] gpio_ir_recv_driver_init+0x20/0x1000 [gpio_ir_recv] [ 19.731404] do_one_initcall+0x44/0x2ac [ 19.735243] do_init_module+0x48/0x1d0 [ 19.739003] load_module+0x19fc/0x2034 [ 19.742759] __do_sys_finit_module+0xac/0x12c [ 19.747124] __arm64_sys_finit_module+0x20/0x30 [ 19.751664] invoke_syscall+0x48/0x114 [ 19.755420] el0_svc_common.constprop.0+0xcc/0xec [ 19.760132] do_el0_svc+0x38/0xb0 [ 19.763456] el0_svc+0x2c/0x84 [ 19.766516] el0t_64_sync_handler+0xf4/0x120 [ 19.770789] el0t_64_sync+0x190/0x194 [ 19.774460] Code: 910003fd a90153f3 aa0003f3 91204021 (f9401400) [ 19.780556] ---[ end trace 0000000000000000 ]--- Signed-off-by: Li Jun <jun.li@nxp.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>

Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000830 Mem abort info: ESR = 0x96000005 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000005 CM = 0, WnR = 0 user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000aaff8145 [0000000000000830] pgd=000000007a5c9003, pud=000000007a5c9003, pmd=0000000000000000 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: Process init (pid: 1, stack limit = 0x00000000722656e6) CPU: 3 PID: 1 Comm: init Not tainted 4.19.232 torvalds#72 Hardware name: Rockchip RK3528 EVB1 DDR4 V10 Board (DT) pstate: 60400005 (nZCv daif +PAN -UAO) pc : __ll_sc___cmpxchg_case_acq_8+0x4/0x20 lr : mutex_lock+0x18/0x40 sp : ffffff800802bc60 x29: ffffff800802bc60 x28: ffffffc07c8e0000 x27: 0000000000000000 x26: 0000000000000000 x25: ffffff8009510d78 x24: ffffff8009cde040 x23: ffffffc07c9e3890 x22: ffffff8009d89000 x21: ffffff8009b73b30 x20: 0000000000000000 x19: 0000000000000830 x18: ffffffffffffffff x17: 0000000000000000 x16: 0000000000000002 x15: ffffff80095ed278 x14: ffffff8089ce4196 x13: ffffff8009ce41b0 x12: ffffff8009ce45d0 x11: ffffff8009adf3b8 x10: 0000000005f5e0ff x9 : 00000000ffffffd0 x8 : 6873203a73756c70 x7 : 0000000000000058 x6 : 0000000000000001 x5 : 0000000000000005 x4 : 0000000000000004 x3 : 0000000000000830 x2 : ffffffc07c8e0000 x1 : 0000000000000000 x0 : 0000000000000830 Call trace: __ll_sc___cmpxchg_case_acq_8+0x4/0x20 rockchip_tve_shutdown+0x1c/0x38 platform_drv_shutdown+0x20/0x30 device_shutdown+0x118/0x200 kernel_restart_prepare+0x34/0x40 kernel_restart+0x14/0x78 __se_sys_reboot+0x1cc/0x208 __arm64_sys_reboot+0x18/0x20 el0_svc_common.constprop.0+0x64/0x178 el0_svc_handler+0x28/0x78 el0_svc+0x8/0xc Signed-off-by: Tao Huang <huangtao@rock-chips.com> Change-Id: Ic1e85b963548e5e66ef78fae5af8dcc12e928fa2

[ Upstream commit 3004081 ] In case runtime PM is enabled, do runtime PM clean up to remove cpu latency qos request, otherwise driver removal may have below kernel dump: [ 19.463299] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000048 [ 19.472161] Mem abort info: [ 19.474985] ESR = 0x0000000096000004 [ 19.478754] EC = 0x25: DABT (current EL), IL = 32 bits [ 19.484081] SET = 0, FnV = 0 [ 19.487149] EA = 0, S1PTW = 0 [ 19.490361] FSC = 0x04: level 0 translation fault [ 19.495256] Data abort info: [ 19.498149] ISV = 0, ISS = 0x00000004 [ 19.501997] CM = 0, WnR = 0 [ 19.504977] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000049f81000 [ 19.511432] [0000000000000048] pgd=0000000000000000, p4d=0000000000000000 [ 19.518245] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 19.524520] Modules linked in: gpio_ir_recv(+) rc_core [last unloaded: rc_core] [ 19.531845] CPU: 0 PID: 445 Comm: insmod Not tainted 6.2.0-rc1-00028-g2c397a46d47c torvalds#72 [ 19.531854] Hardware name: FSL i.MX8MM EVK board (DT) [ 19.531859] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 19.551777] pc : cpu_latency_qos_remove_request+0x20/0x110 [ 19.557277] lr : gpio_ir_recv_runtime_suspend+0x18/0x30 [gpio_ir_recv] [ 19.557294] sp : ffff800008ce3740 [ 19.557297] x29: ffff800008ce3740 x28: 0000000000000000 x27: ffff800008ce3d50 [ 19.574270] x26: ffffc7e3e9cea100 x25: 00000000000f4240 x24: ffffc7e3f9ef0e30 [ 19.574284] x23: 0000000000000000 x22: ffff0061803820f4 x21: 0000000000000008 [ 19.574296] x20: ffffc7e3fa75df30 x19: 0000000000000020 x18: ffffffffffffffff [ 19.588570] x17: 0000000000000000 x16: ffffc7e3f9efab70 x15: ffffffffffffffff [ 19.595712] x14: ffff800008ce37b8 x13: ffff800008ce37aa x12: 0000000000000001 [ 19.602853] x11: 0000000000000001 x10: ffffcbe3ec0dff87 x9 : 0000000000000008 [ 19.609991] x8 : 0101010101010101 x7 : 0000000000000000 x6 : 000000000f0bfe9f [ 19.624261] x5 : 00ffffffffffffff x4 : 0025ab8e00000000 x3 : ffff006180382010 [ 19.631405] x2 : ffffc7e3e9ce8030 x1 : ffffc7e3fc3eb810 x0 : 0000000000000020 [ 19.638548] Call trace: [ 19.640995] cpu_latency_qos_remove_request+0x20/0x110 [ 19.646142] gpio_ir_recv_runtime_suspend+0x18/0x30 [gpio_ir_recv] [ 19.652339] pm_generic_runtime_suspend+0x2c/0x44 [ 19.657055] __rpm_callback+0x48/0x1dc [ 19.660807] rpm_callback+0x6c/0x80 [ 19.664301] rpm_suspend+0x10c/0x640 [ 19.667880] rpm_idle+0x250/0x2d0 [ 19.671198] update_autosuspend+0x38/0xe0 [ 19.675213] pm_runtime_set_autosuspend_delay+0x40/0x60 [ 19.680442] gpio_ir_recv_probe+0x1b4/0x21c [gpio_ir_recv] [ 19.685941] platform_probe+0x68/0xc0 [ 19.689610] really_probe+0xc0/0x3dc [ 19.693189] __driver_probe_device+0x7c/0x190 [ 19.697550] driver_probe_device+0x3c/0x110 [ 19.701739] __driver_attach+0xf4/0x200 [ 19.705578] bus_for_each_dev+0x70/0xd0 [ 19.709417] driver_attach+0x24/0x30 [ 19.712998] bus_add_driver+0x17c/0x240 [ 19.716834] driver_register+0x78/0x130 [ 19.720676] __platform_driver_register+0x28/0x34 [ 19.725386] gpio_ir_recv_driver_init+0x20/0x1000 [gpio_ir_recv] [ 19.731404] do_one_initcall+0x44/0x2ac [ 19.735243] do_init_module+0x48/0x1d0 [ 19.739003] load_module+0x19fc/0x2034 [ 19.742759] __do_sys_finit_module+0xac/0x12c [ 19.747124] __arm64_sys_finit_module+0x20/0x30 [ 19.751664] invoke_syscall+0x48/0x114 [ 19.755420] el0_svc_common.constprop.0+0xcc/0xec [ 19.760132] do_el0_svc+0x38/0xb0 [ 19.763456] el0_svc+0x2c/0x84 [ 19.766516] el0t_64_sync_handler+0xf4/0x120 [ 19.770789] el0t_64_sync+0x190/0x194 [ 19.774460] Code: 910003fd a90153f3 aa0003f3 91204021 (f9401400) [ 19.780556] ---[ end trace 0000000000000000 ]--- Signed-off-by: Li Jun <jun.li@nxp.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>

More than 8 whitespaces of the code indent are replaced with "tab + whitespaces" to fix up such errors reported by scripts/checkpatch.pl: ERROR: code indent should use tabs where possible torvalds#64: FILE: tools/include/nolibc/arch-mips.h:64: +^I \$ ERROR: code indent should use tabs where possible torvalds#72: FILE: tools/include/nolibc/arch-mips.h:72: +^I "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "t8", "t9" \$ This command is used: $ sed -i -e '/^\t* /{s/ /\t/g}' tools/include/nolibc/arch-*.h Signed-off-by: Zhangjin Wu <falcon@tinylab.org> Signed-off-by: Willy Tarreau <w@1wt.eu>

KSAN calls into rcu code which then triggers a write that reenters into KSAN getting the system stuck doing infinite recursion. #0 kmsan_get_context () at mm/kmsan/kmsan.h:106 #1 __msan_get_context_state () at mm/kmsan/instrumentation.c:331 #2 0xffffffff81495671 in get_current () at ./arch/x86/include/asm/current.h:42 #3 rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 #4 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 #5 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#6 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#7 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#8 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#9 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#10 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#11 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#12 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#13 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#14 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#15 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#16 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#17 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#18 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#19 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#20 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#21 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#22 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#23 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#24 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#25 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#26 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#27 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#28 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#29 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#30 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#31 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#32 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#33 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#34 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#35 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#36 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#37 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#38 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#39 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#40 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#41 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#42 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#43 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#44 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#45 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#46 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#47 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#48 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#49 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#50 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#51 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 #52 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 #53 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#54 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#55 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#56 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#57 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 #58 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#59 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#60 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#61 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#62 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#63 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#64 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#65 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#66 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#67 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#68 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#69 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 #70 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#71 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#72 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#73 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#74 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#75 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#76 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#77 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff86203c90) at ./arch/x86/include/asm/kmsan.h:82 torvalds#78 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff86203c90) at mm/kmsan/shadow.c:75 torvalds#79 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff86203c90, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#80 kmsan_get_shadow_origin_ptr (address=0xffffffff86203c90, size=8, store=false) at mm/kmsan/shadow.c:97 torvalds#81 0xffffffff81b1dc72 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=8, store=false) at mm/kmsan/instrumentation.c:36 torvalds#82 __msan_metadata_ptr_for_load_8 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:92 torvalds#83 0xffffffff814fdb9e in filter_irq_stacks (entries=<optimized out>, nr_entries=4) at kernel/stacktrace.c:397 torvalds#84 0xffffffff829520e8 in stack_depot_save_flags (entries=0xffffffff8620d974 <init_task+1012>, nr_entries=4, alloc_flags=0, depot_flags=0) at lib/stackdepot.c:500 torvalds#85 0xffffffff81b1e560 in __msan_poison_alloca (address=0xffffffff86203da0, size=24, descr=<optimized out>) at mm/kmsan/instrumentation.c:285 torvalds#86 0xffffffff8562821c in _printk (fmt=0xffffffff85f191a5 "\0016Attempting lock1") at kernel/printk/printk.c:2324 torvalds#87 0xffffffff81942aa2 in kmem_cache_create_usercopy (name=0xffffffff85f18903 "mm_struct", size=1296, align=0, flags=270336, useroffset=<optimized out>, usersize=<optimized out>, ctor=0x0 <fixed_percpu_data>) at mm/slab_common.c:296 torvalds#88 0xffffffff86f337a0 in mm_cache_init () at kernel/fork.c:3262 torvalds#89 0xffffffff86eacb8e in start_kernel () at init/main.c:932 torvalds#90 0xffffffff86ecdf94 in x86_64_start_reservations (real_mode_data=0x140e0 <exception_stacks+28896> <error: Cannot access memory at address 0x140e0>) at arch/x86/kernel/head64.c:555 torvalds#91 0xffffffff86ecde9b in x86_64_start_kernel (real_mode_data=0x140e0 <exception_stacks+28896> <error: Cannot access memory at address 0x140e0>) at arch/x86/kernel/head64.c:536 torvalds#92 0xffffffff810001d3 in secondary_startup_64 () at /pool/workspace/linux/arch/x86/kernel/head_64.S:461 torvalds#93 0x0000000000000000 in ??

As of 5ec8e8e(mm/sparsemem: fix race in accessing memory_section->usage) KMSAN now calls into RCU tree code during kmsan_get_metadata. This will trigger a write that will reenter into KMSAN getting the system stuck doing infinite recursion. #0 kmsan_get_context () at mm/kmsan/kmsan.h:106 #1 __msan_get_context_state () at mm/kmsan/instrumentation.c:331 #2 0xffffffff81495671 in get_current () at ./arch/x86/include/asm/current.h:42 #3 rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 #4 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 #5 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#6 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#7 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#8 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#9 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#10 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#11 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#12 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#13 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#14 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#15 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#16 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#17 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#18 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#19 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#20 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#21 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#22 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#23 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#24 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#25 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#26 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#27 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#28 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#29 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#30 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#31 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#32 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#33 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#34 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#35 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#36 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#37 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#38 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#39 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#40 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#41 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#42 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#43 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#44 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#45 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#46 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#47 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#48 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#49 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#50 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#51 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 #52 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 #53 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#54 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#55 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#56 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#57 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 #58 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#59 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#60 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#61 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#62 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#63 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#64 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#65 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#66 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#67 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff8620d974 <init_task+1012>) at ./arch/x86/include/asm/kmsan.h:82 torvalds#68 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/shadow.c:75 torvalds#69 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff8620d974 <init_task+1012>, is_origin=false) at mm/kmsan/shadow.c:143 #70 kmsan_get_shadow_origin_ptr (address=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/shadow.c:97 torvalds#71 0xffffffff81b1dbd2 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=4, store=false) at mm/kmsan/instrumentation.c:36 torvalds#72 __msan_metadata_ptr_for_load_4 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:91 torvalds#73 0xffffffff8149568f in rcu_preempt_read_enter () at kernel/rcu/tree_plugin.h:379 torvalds#74 __rcu_read_lock () at kernel/rcu/tree_plugin.h:402 torvalds#75 0xffffffff81b2054b in rcu_read_lock () at ./include/linux/rcupdate.h:748 torvalds#76 pfn_valid (pfn=<optimized out>) at ./include/linux/mmzone.h:2016 torvalds#77 kmsan_virt_addr_valid (addr=addr@entry=0xffffffff86203c90) at ./arch/x86/include/asm/kmsan.h:82 torvalds#78 virt_to_page_or_null (vaddr=vaddr@entry=0xffffffff86203c90) at mm/kmsan/shadow.c:75 torvalds#79 0xffffffff81b2023c in kmsan_get_metadata (address=0xffffffff86203c90, is_origin=false) at mm/kmsan/shadow.c:143 torvalds#80 kmsan_get_shadow_origin_ptr (address=0xffffffff86203c90, size=8, store=false) at mm/kmsan/shadow.c:97 torvalds#81 0xffffffff81b1dc72 in get_shadow_origin_ptr (addr=0xffffffff8620d974 <init_task+1012>, size=8, store=false) at mm/kmsan/instrumentation.c:36 torvalds#82 __msan_metadata_ptr_for_load_8 (addr=0xffffffff8620d974 <init_task+1012>) at mm/kmsan/instrumentation.c:92 torvalds#83 0xffffffff814fdb9e in filter_irq_stacks (entries=<optimized out>, nr_entries=4) at kernel/stacktrace.c:397 torvalds#84 0xffffffff829520e8 in stack_depot_save_flags (entries=0xffffffff8620d974 <init_task+1012>, nr_entries=4, alloc_flags=0, depot_flags=0) at lib/stackdepot.c:500 torvalds#85 0xffffffff81b1e560 in __msan_poison_alloca (address=0xffffffff86203da0, size=24, descr=<optimized out>) at mm/kmsan/instrumentation.c:285 torvalds#86 0xffffffff8562821c in _printk (fmt=0xffffffff85f191a5 "\0016Attempting lock1") at kernel/printk/printk.c:2324 torvalds#87 0xffffffff81942aa2 in kmem_cache_create_usercopy (name=0xffffffff85f18903 "mm_struct", size=1296, align=0, flags=270336, useroffset=<optimized out>, usersize=<optimized out>, ctor=0x0 <fixed_percpu_data>) at mm/slab_common.c:296 torvalds#88 0xffffffff86f337a0 in mm_cache_init () at kernel/fork.c:3262 torvalds#89 0xffffffff86eacb8e in start_kernel () at init/main.c:932 torvalds#90 0xffffffff86ecdf94 in x86_64_start_reservations (real_mode_data=0x140e0 <exception_stacks+28896> <error: Cannot access memory at address 0x140e0>) at arch/x86/kernel/head64.c:555 torvalds#91 0xffffffff86ecde9b in x86_64_start_kernel (real_mode_data=0x140e0 <exception_stacks+28896> <error: Cannot access memory at address 0x140e0>) at arch/x86/kernel/head64.c:536 torvalds#92 0xffffffff810001d3 in secondary_startup_64 () at /pool/workspace/linux/arch/x86/kernel/head_64.S:461 torvalds#93 0x0000000000000000 in ??

This patch fixes a tailcall infinite loop issue caused by freplace. Since commit 1c123c5 ("bpf: Resolve fext program type when checking map compatibility"), freplace prog is allowed to tail call its target prog. Then, when a freplace prog attaches to its target prog's subprog and tail calls its target prog, kernel will panic. For example: tc_bpf2bpf.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> __noinline int subprog_tc(struct __sk_buff *skb) { return skb->len * 2; } SEC("tc") int entry_tc(struct __sk_buff *skb) { return subprog_tc(skb); } char __license[] SEC("license") = "GPL"; tailcall_bpf2bpf_hierarchy_freplace.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> struct { __uint(type, BPF_MAP_TYPE_PROG_ARRAY); __uint(max_entries, 1); __uint(key_size, sizeof(__u32)); __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); int count = 0; static __noinline int subprog_tail(struct __sk_buff *skb) { bpf_tail_call_static(skb, &jmp_table, 0); return 0; } SEC("freplace") int entry_freplace(struct __sk_buff *skb) { count++; subprog_tail(skb); subprog_tail(skb); return count; } char __license[] SEC("license") = "GPL"; The attach target of entry_freplace is subprog_tc, and the tail callee in subprog_tail is entry_tc. Then, the infinite loop will be entry_tc -> subprog_tc -> entry_freplace -> subprog_tail --tailcall-> entry_tc, because tail_call_cnt in entry_freplace will count from zero for every time of entry_freplace execution. Kernel will panic: [ 15.310490] BUG: TASK stack guard page was hit at (____ptrval____) (stack is (____ptrval____)..(____ptrval____)) [ 15.310490] Oops: stack guard page: 0000 [#1] PREEMPT SMP NOPTI [ 15.310490] CPU: 1 PID: 89 Comm: test_progs Tainted: G OE 6.10.0-rc6-g026dcdae8d3e-dirty torvalds#72 [ 15.310490] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Call Trace: [ 15.310490] <#DF> [ 15.310490] ? die+0x36/0x90 [ 15.310490] ? handle_stack_overflow+0x4d/0x60 [ 15.310490] ? exc_double_fault+0x117/0x1a0 [ 15.310490] ? asm_exc_double_fault+0x23/0x30 [ 15.310490] ? bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] </#DF> [ 15.310490] <TASK> [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] ... [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] bpf_test_run+0x210/0x370 [ 15.310490] ? bpf_test_run+0x128/0x370 [ 15.310490] bpf_prog_test_run_skb+0x388/0x7a0 [ 15.310490] __sys_bpf+0xdbf/0x2c40 [ 15.310490] ? clockevents_program_event+0x52/0xf0 [ 15.310490] ? lock_release+0xbf/0x290 [ 15.310490] __x64_sys_bpf+0x1e/0x30 [ 15.310490] do_syscall_64+0x68/0x140 [ 15.310490] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 15.310490] RIP: 0033:0x7f133b52725d [ 15.310490] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48 [ 15.310490] RSP: 002b:00007ffddbc10258 EFLAGS: 00000206 ORIG_RAX: 0000000000000141 [ 15.310490] RAX: ffffffffffffffda RBX: 00007ffddbc10828 RCX: 00007f133b52725d [ 15.310490] RDX: 0000000000000050 RSI: 00007ffddbc102a0 RDI: 000000000000000a [ 15.310490] RBP: 00007ffddbc10270 R08: 0000000000000000 R09: 00007ffddbc102a0 [ 15.310490] R10: 0000000000000064 R11: 0000000000000206 R12: 0000000000000004 [ 15.310490] R13: 0000000000000000 R14: 0000558ec4c24890 R15: 00007f133b6ed000 [ 15.310490] </TASK> [ 15.310490] Modules linked in: bpf_testmod(OE) [ 15.310490] ---[ end trace 0000000000000000 ]--- [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Kernel panic - not syncing: Fatal exception in interrupt [ 15.310490] Kernel Offset: 0x30000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) This patch fixes the issue by initializing tail_call_cnt at the prologue of entry_tc. Next, when call subprog_tc, the tail_call_cnt_ptr is propagated to subprog_tc by rax. Next, when jump to entry_freplace, the tail_call_cnt_ptr will be reused to count tailcall in freplace prog. Next, when call subprog_tail, the tail_call_cnt_ptr is propagated to subprog_tail by rax. Next, while tail calling to entry_tc, the tail_call_cnt on the stack of entry_tc increments via the tail_call_cnt_ptr. The whole procedure shows as the following JITed prog dumping. bpftool p d j n entry_tc: int entry_tc(struct __sk_buff * skb): bpf_prog_1c515f389a9059b4_entry_tc: ; return subprog_tc(skb); 0: endbr64 4: xorq %rax, %rax ;; rax = 0 (tail_call_cnt) 7: nopl (%rax,%rax) c: pushq %rbp d: movq %rsp, %rbp 10: endbr64 14: cmpq $33, %rax ;; if rax > 33, rax = tcc_ptr 18: ja 0x20 ;; if rax > 33 goto 0x20 ---+ 1a: pushq %rax ;; [rbp - 8] = rax = 0 | 1b: movq %rsp, %rax ;; rax = rbp - 8 | 1e: jmp 0x21 ;; ---------+ | 20: pushq %rax ;; <--------|---------------+ 21: pushq %rax ;; <--------+ [rbp - 16] = rax 22: movq -16(%rbp), %rax ;; rax = tcc_ptr 29: callq 0x70 ;; call subprog_tc() ; return subprog_tc(skb); 2e: leave 2f: retq int subprog_tc(struct __sk_buff * skb): bpf_prog_1e8f76e2374a0607_subprog_tc: ; return skb->len * 2; 0: endbr64 4: nopl (%rax) ;; do not touch tail_call_cnt 7: jmp 0x108 ;; jump to entry_freplace() c: pushq %rbp d: movq %rsp, %rbp 10: endbr64 14: pushq %rax 15: pushq %rax 16: movl 112(%rdi), %eax ; return skb->len * 2; 19: shll %eax ; return skb->len * 2; 1b: leave 1c: retq bpftool p d j n entry_freplace: int entry_freplace(struct __sk_buff * skb): bpf_prog_85781a698094722f_entry_freplace: ; int entry_freplace(struct __sk_buff *skb) 0: endbr64 4: nopl (%rax) ;; do not touch tail_call_cnt 7: nopl (%rax,%rax) c: pushq %rbp d: movq %rsp, %rbp 10: endbr64 14: cmpq $33, %rax ;; if rax > 33, rax = tcc_ptr 18: ja 0x20 ;; if rax > 33 goto 0x20 ---+ 1a: pushq %rax ;; [rbp - 8] = rax = 0 | 1b: movq %rsp, %rax ;; rax = rbp - 8 | 1e: jmp 0x21 ;; ---------+ | 20: pushq %rax ;; <--------|---------------+ 21: pushq %rax ;; <--------+ [rbp - 16] = rax 22: pushq %rbx ;; callee saved 23: pushq %r13 ;; callee saved 25: movq %rdi, %rbx ;; rbx = skb (callee saved) ; count++; 28: movabsq $-123406219759616, %r13 32: movl (%r13), %edi 36: addl $1, %edi 39: movl %edi, (%r13) ; subprog_tail(skb); 3d: movq %rbx, %rdi ;; rdi = skb 40: movq -16(%rbp), %rax ;; rax = tcc_ptr 47: callq 0x80 ;; call subprog_tail() ; subprog_tail(skb); 4c: movq %rbx, %rdi ;; rdi = skb 4f: movq -16(%rbp), %rax ;; rax = tcc_ptr 56: callq 0x80 ;; call subprog_tail() ; return count; 5b: movl (%r13), %eax ; return count; 5f: popq %r13 61: popq %rbx 62: leave 63: retq int subprog_tail(struct __sk_buff * skb): bpf_prog_3a140cef239a4b4f_subprog_tail: ; int subprog_tail(struct __sk_buff *skb) 0: endbr64 4: nopl (%rax) ;; do not touch tail_call_cnt 7: nopl (%rax,%rax) c: pushq %rbp d: movq %rsp, %rbp 10: endbr64 14: pushq %rax ;; [rbp - 8] = rax (tcc_ptr) 15: pushq %rax ;; [rbp - 16] = rax (tcc_ptr) 16: pushq %rbx ;; callee saved 17: pushq %r13 ;; callee saved 19: movq %rdi, %rbx ;; rbx = skb ; asm volatile("r1 = %[ctx]\n\t" 1c: movabsq $-128494642337280, %r13 ;; r13 = jmp_table 26: movq %rbx, %rdi ;; 1st arg, skb 29: movq %r13, %rsi ;; 2nd arg, jmp_table 2c: xorl %edx, %edx ;; 3rd arg, index = 0 2e: movq -16(%rbp), %rax ;; rax = [rbp - 16] (tcc_ptr) 35: cmpq $33, (%rax) 39: jae 0x4e ;; if *tcc_ptr >= 33 goto 0x4e --------+ 3b: nopl (%rax,%rax) ;; jmp bypass, toggled by poking | 40: addq $1, (%rax) ;; (*tcc_ptr)++ | 44: popq %r13 ;; callee saved | 46: popq %rbx ;; callee saved | 47: popq %rax ;; undo rbp-16 push | 48: popq %rax ;; undo rbp-8 push | 49: jmp 0xfffffffffffffe18 ;; tail call target, toggled by poking | ; return 0; ;; | 4e: popq %r13 ;; restore callee saved <--------------+ 50: popq %rbx ;; restore callee saved 51: leave 52: retq As a result, the tail_call_cnt is stored on the stack of entry_tc. And the tail_call_cnt_ptr is propagated between subprog_tc, entry_freplace, subprog_tail and entry_tc. Furthermore, trampoline is required to propagate tail_call_cnt/tail_call_cnt_ptr always, no matter whether there is tailcall at run time. So, it reuses trampoline flag "BIT(7)" to tell trampoline to propagate the tail_call_cnt/tail_call_cnt_ptr, as BPF_TRAMP_F_TAIL_CALL_CTX is not used by any other arch BPF JIT. However, the bad effect is that it requires initializing tail_call_cnt at prologue always no matter whether the prog is tail_call_reachable, because it is unable to confirm itself or its subprog[s] whether to be attached by freplace prog. And, when call subprog, tail_call_cnt_ptr is required to be propagated to subprog always. Fixes: 1c123c5 ("bpf: Resolve fext program type when checking map compatibility") Signed-off-by: Leon Hwang <leon.hwang@linux.dev>

This patch fixes a tailcall infinite loop issue caused by freplace. Since commit 1c123c5 ("bpf: Resolve fext program type when checking map compatibility"), freplace prog is allowed to tail call its target prog. Then, when a freplace prog attaches to its target prog's subprog and tail calls its target prog, kernel will panic. For example: tc_bpf2bpf.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> __noinline int subprog_tc(struct __sk_buff *skb) { return skb->len * 2; } SEC("tc") int entry_tc(struct __sk_buff *skb) { return subprog_tc(skb); } char __license[] SEC("license") = "GPL"; tailcall_bpf2bpf_hierarchy_freplace.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> struct { __uint(type, BPF_MAP_TYPE_PROG_ARRAY); __uint(max_entries, 1); __uint(key_size, sizeof(__u32)); __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); int count = 0; static __noinline int subprog_tail(struct __sk_buff *skb) { bpf_tail_call_static(skb, &jmp_table, 0); return 0; } SEC("freplace") int entry_freplace(struct __sk_buff *skb) { count++; subprog_tail(skb); subprog_tail(skb); return count; } char __license[] SEC("license") = "GPL"; The attach target of entry_freplace is subprog_tc, and the tail callee in subprog_tail is entry_tc. Then, the infinite loop will be entry_tc -> subprog_tc -> entry_freplace -> subprog_tail --tailcall-> entry_tc, because tail_call_cnt in entry_freplace will count from zero for every time of entry_freplace execution. Kernel will panic: [ 15.310490] BUG: TASK stack guard page was hit at (____ptrval____) (stack is (____ptrval____)..(____ptrval____)) [ 15.310490] Oops: stack guard page: 0000 [#1] PREEMPT SMP NOPTI [ 15.310490] CPU: 1 PID: 89 Comm: test_progs Tainted: G OE 6.10.0-rc6-g026dcdae8d3e-dirty torvalds#72 [ 15.310490] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Call Trace: [ 15.310490] <#DF> [ 15.310490] ? die+0x36/0x90 [ 15.310490] ? handle_stack_overflow+0x4d/0x60 [ 15.310490] ? exc_double_fault+0x117/0x1a0 [ 15.310490] ? asm_exc_double_fault+0x23/0x30 [ 15.310490] ? bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] </#DF> [ 15.310490] <TASK> [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] ... [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] bpf_test_run+0x210/0x370 [ 15.310490] ? bpf_test_run+0x128/0x370 [ 15.310490] bpf_prog_test_run_skb+0x388/0x7a0 [ 15.310490] __sys_bpf+0xdbf/0x2c40 [ 15.310490] ? clockevents_program_event+0x52/0xf0 [ 15.310490] ? lock_release+0xbf/0x290 [ 15.310490] __x64_sys_bpf+0x1e/0x30 [ 15.310490] do_syscall_64+0x68/0x140 [ 15.310490] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 15.310490] RIP: 0033:0x7f133b52725d [ 15.310490] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48 [ 15.310490] RSP: 002b:00007ffddbc10258 EFLAGS: 00000206 ORIG_RAX: 0000000000000141 [ 15.310490] RAX: ffffffffffffffda RBX: 00007ffddbc10828 RCX: 00007f133b52725d [ 15.310490] RDX: 0000000000000050 RSI: 00007ffddbc102a0 RDI: 000000000000000a [ 15.310490] RBP: 00007ffddbc10270 R08: 0000000000000000 R09: 00007ffddbc102a0 [ 15.310490] R10: 0000000000000064 R11: 0000000000000206 R12: 0000000000000004 [ 15.310490] R13: 0000000000000000 R14: 0000558ec4c24890 R15: 00007f133b6ed000 [ 15.310490] </TASK> [ 15.310490] Modules linked in: bpf_testmod(OE) [ 15.310490] ---[ end trace 0000000000000000 ]--- [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Kernel panic - not syncing: Fatal exception in interrupt [ 15.310490] Kernel Offset: 0x30000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) This patch fixes the issue by initializing tail_call_cnt at the prologue of entry_tc. Next, when call subprog_tc, the tail_call_cnt_ptr is propagated to subprog_tc by rax. Next, when jump to entry_freplace, the tail_call_cnt_ptr will be reused to count tailcall in freplace prog. Next, when call subprog_tail, the tail_call_cnt_ptr is propagated to subprog_tail by rax. Next, while tail calling to entry_tc, the tail_call_cnt on the stack of entry_tc increments via the tail_call_cnt_ptr. The whole procedure shows as the following JITed prog dumping. bpftool p d j n entry_tc: int entry_tc(struct __sk_buff * skb): bpf_prog_1c515f389a9059b4_entry_tc: ; return subprog_tc(skb); 0: endbr64 4: xorq %rax, %rax ;; rax = 0 (tail_call_cnt) 7: nopl (%rax,%rax) c: pushq %rbp d: movq %rsp, %rbp 10: endbr64 14: cmpq $33, %rax ;; if rax > 33, rax = tcc_ptr 18: ja 0x20 ;; if rax > 33 goto 0x20 ---+ 1a: pushq %rax ;; [rbp - 8] = rax = 0 | 1b: movq %rsp, %rax ;; rax = rbp - 8 | 1e: jmp 0x21 ;; ---------+ | 20: pushq %rax ;; <--------|---------------+ 21: pushq %rax ;; <--------+ [rbp - 16] = rax 22: movq -16(%rbp), %rax ;; rax = tcc_ptr 29: callq 0x70 ;; call subprog_tc() ; return subprog_tc(skb); 2e: leave 2f: retq int subprog_tc(struct __sk_buff * skb): bpf_prog_1e8f76e2374a0607_subprog_tc: ; return skb->len * 2; 0: endbr64 4: nopl (%rax) ;; do not touch tail_call_cnt 7: jmp 0x108 ;; jump to entry_freplace() c: pushq %rbp d: movq %rsp, %rbp 10: endbr64 14: pushq %rax 15: pushq %rax 16: movl 112(%rdi), %eax ; return skb->len * 2; 19: shll %eax ; return skb->len * 2; 1b: leave 1c: retq bpftool p d j n entry_freplace: int entry_freplace(struct __sk_buff * skb): bpf_prog_85781a698094722f_entry_freplace: ; int entry_freplace(struct __sk_buff *skb) 0: endbr64 4: nopl (%rax) ;; do not touch tail_call_cnt 7: nopl (%rax,%rax) c: pushq %rbp d: movq %rsp, %rbp 10: endbr64 14: cmpq $33, %rax ;; if rax > 33, rax = tcc_ptr 18: ja 0x20 ;; if rax > 33 goto 0x20 ---+ 1a: pushq %rax ;; [rbp - 8] = rax = 0 | 1b: movq %rsp, %rax ;; rax = rbp - 8 | 1e: jmp 0x21 ;; ---------+ | 20: pushq %rax ;; <--------|---------------+ 21: pushq %rax ;; <--------+ [rbp - 16] = rax 22: pushq %rbx ;; callee saved 23: pushq %r13 ;; callee saved 25: movq %rdi, %rbx ;; rbx = skb (callee saved) ; count++; 28: movabsq $-123406219759616, %r13 32: movl (%r13), %edi 36: addl $1, %edi 39: movl %edi, (%r13) ; subprog_tail(skb); 3d: movq %rbx, %rdi ;; rdi = skb 40: movq -16(%rbp), %rax ;; rax = tcc_ptr 47: callq 0x80 ;; call subprog_tail() ; subprog_tail(skb); 4c: movq %rbx, %rdi ;; rdi = skb 4f: movq -16(%rbp), %rax ;; rax = tcc_ptr 56: callq 0x80 ;; call subprog_tail() ; return count; 5b: movl (%r13), %eax ; return count; 5f: popq %r13 61: popq %rbx 62: leave 63: retq int subprog_tail(struct __sk_buff * skb): bpf_prog_3a140cef239a4b4f_subprog_tail: ; int subprog_tail(struct __sk_buff *skb) 0: endbr64 4: nopl (%rax) ;; do not touch tail_call_cnt 7: nopl (%rax,%rax) c: pushq %rbp d: movq %rsp, %rbp 10: endbr64 14: pushq %rax ;; [rbp - 8] = rax (tcc_ptr) 15: pushq %rax ;; [rbp - 16] = rax (tcc_ptr) 16: pushq %rbx ;; callee saved 17: pushq %r13 ;; callee saved 19: movq %rdi, %rbx ;; rbx = skb ; asm volatile("r1 = %[ctx]\n\t" 1c: movabsq $-128494642337280, %r13 ;; r13 = jmp_table 26: movq %rbx, %rdi ;; 1st arg, skb 29: movq %r13, %rsi ;; 2nd arg, jmp_table 2c: xorl %edx, %edx ;; 3rd arg, index = 0 2e: movq -16(%rbp), %rax ;; rax = [rbp - 16] (tcc_ptr) 35: cmpq $33, (%rax) 39: jae 0x4e ;; if *tcc_ptr >= 33 goto 0x4e --------+ 3b: nopl (%rax,%rax) ;; jmp bypass, toggled by poking | 40: addq $1, (%rax) ;; (*tcc_ptr)++ | 44: popq %r13 ;; callee saved | 46: popq %rbx ;; callee saved | 47: popq %rax ;; undo rbp-16 push | 48: popq %rax ;; undo rbp-8 push | 49: jmp 0xfffffffffffffe18 ;; tail call target, toggled by poking | ; return 0; ;; | 4e: popq %r13 ;; restore callee saved <--------------+ 50: popq %rbx ;; restore callee saved 51: leave 52: retq As a result, the tail_call_cnt is stored on the stack of entry_tc. And the tail_call_cnt_ptr is propagated between subprog_tc, entry_freplace, subprog_tail and entry_tc. But wait, what if entry_freplace has tailcall and entry_tc has no tailcall? It's to disallow attaching this entry_freplace to this entry_tc in verifier. And, what if entry_freplace has tailcall and entry_tc has tailcall and entry_freplace attaches to entry_tc? In this patch, the tailcall info of entry_freplace inherits from its target. Therefore, it swaps the positions of nop5 and xor/nop3 in order to initialize tail_call_cnt at the prologue of entry_tc and then propagate the tail_call_cnt to entry_freplace. Fixes: 1c123c5 ("bpf: Resolve fext program type when checking map compatibility") Signed-off-by: Leon Hwang <leon.hwang@linux.dev>

This patch prevents a potential infinite loop issue caused by combination of tailcal and freplace partially. For example: tc_bpf2bpf.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> __noinline int subprog_tc(struct __sk_buff *skb) { return skb->len * 2; } SEC("tc") int entry_tc(struct __sk_buff *skb) { return subprog_tc(skb); } char __license[] SEC("license") = "GPL"; tailcall_bpf2bpf_hierarchy_freplace.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> struct { __uint(type, BPF_MAP_TYPE_PROG_ARRAY); __uint(max_entries, 1); __uint(key_size, sizeof(__u32)); __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); int count = 0; static __noinline int subprog_tail(struct __sk_buff *skb) { bpf_tail_call_static(skb, &jmp_table, 0); return 0; } SEC("freplace") int entry_freplace(struct __sk_buff *skb) { count++; subprog_tail(skb); subprog_tail(skb); return count; } char __license[] SEC("license") = "GPL"; The attach target of entry_freplace is subprog_tc, and the tail callee in subprog_tail is entry_tc. Then, the infinite loop will be entry_tc -> subprog_tc -> entry_freplace -> subprog_tail --tailcall-> entry_tc, because tail_call_cnt in entry_freplace will count from zero for every time of entry_freplace execution. Kernel will panic: [ 15.310490] BUG: TASK stack guard page was hit at (____ptrval____) (stack is (____ptrval____)..(____ptrval____)) [ 15.310490] Oops: stack guard page: 0000 [#1] PREEMPT SMP NOPTI [ 15.310490] CPU: 1 PID: 89 Comm: test_progs Tainted: G OE 6.10.0-rc6-g026dcdae8d3e-dirty torvalds#72 [ 15.310490] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Call Trace: [ 15.310490] <#DF> [ 15.310490] ? die+0x36/0x90 [ 15.310490] ? handle_stack_overflow+0x4d/0x60 [ 15.310490] ? exc_double_fault+0x117/0x1a0 [ 15.310490] ? asm_exc_double_fault+0x23/0x30 [ 15.310490] ? bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] </#DF> [ 15.310490] <TASK> [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] ... [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] bpf_test_run+0x210/0x370 [ 15.310490] ? bpf_test_run+0x128/0x370 [ 15.310490] bpf_prog_test_run_skb+0x388/0x7a0 [ 15.310490] __sys_bpf+0xdbf/0x2c40 [ 15.310490] ? clockevents_program_event+0x52/0xf0 [ 15.310490] ? lock_release+0xbf/0x290 [ 15.310490] __x64_sys_bpf+0x1e/0x30 [ 15.310490] do_syscall_64+0x68/0x140 [ 15.310490] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 15.310490] RIP: 0033:0x7f133b52725d [ 15.310490] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48 [ 15.310490] RSP: 002b:00007ffddbc10258 EFLAGS: 00000206 ORIG_RAX: 0000000000000141 [ 15.310490] RAX: ffffffffffffffda RBX: 00007ffddbc10828 RCX: 00007f133b52725d [ 15.310490] RDX: 0000000000000050 RSI: 00007ffddbc102a0 RDI: 000000000000000a [ 15.310490] RBP: 00007ffddbc10270 R08: 0000000000000000 R09: 00007ffddbc102a0 [ 15.310490] R10: 0000000000000064 R11: 0000000000000206 R12: 0000000000000004 [ 15.310490] R13: 0000000000000000 R14: 0000558ec4c24890 R15: 00007f133b6ed000 [ 15.310490] </TASK> [ 15.310490] Modules linked in: bpf_testmod(OE) [ 15.310490] ---[ end trace 0000000000000000 ]--- [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Kernel panic - not syncing: Fatal exception in interrupt [ 15.310490] Kernel Offset: 0x30000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) This patch partially prevents this panic by preventing updating extended prog to prog_array map. If a prog or its subprog has been extended by freplace prog, the prog can not be updated to prog_array map. Alongside next patch, the panic will be prevented completely. Signed-off-by: Leon Hwang <leon.hwang@linux.dev>

This patch partially prevents a potential infinite loop issue caused by combination of tailcal and freplace. For example: tc_bpf2bpf.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> __noinline int subprog_tc(struct __sk_buff *skb) { return skb->len * 2; } SEC("tc") int entry_tc(struct __sk_buff *skb) { return subprog_tc(skb); } char __license[] SEC("license") = "GPL"; tailcall_freplace.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> struct { __uint(type, BPF_MAP_TYPE_PROG_ARRAY); __uint(max_entries, 1); __uint(key_size, sizeof(__u32)); __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); int count = 0; SEC("freplace") int entry_freplace(struct __sk_buff *skb) { count++; bpf_tail_call_static(skb, &jmp_table, 0); return count; } char __license[] SEC("license") = "GPL"; The attach target of entry_freplace is subprog_tc, and the tail callee in entry_freplace is entry_tc. Then, the infinite loop will be entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc, because tail_call_cnt in entry_freplace will count from zero for every time of entry_freplace execution. Kernel will panic, like: [ 15.310490] BUG: TASK stack guard page was hit at (____ptrval____) (stack is (____ptrval____)..(____ptrval____)) [ 15.310490] Oops: stack guard page: 0000 [#1] PREEMPT SMP NOPTI [ 15.310490] CPU: 1 PID: 89 Comm: test_progs Tainted: G OE 6.10.0-rc6-g026dcdae8d3e-dirty torvalds#72 [ 15.310490] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Call Trace: [ 15.310490] <#DF> [ 15.310490] ? die+0x36/0x90 [ 15.310490] ? handle_stack_overflow+0x4d/0x60 [ 15.310490] ? exc_double_fault+0x117/0x1a0 [ 15.310490] ? asm_exc_double_fault+0x23/0x30 [ 15.310490] ? bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] </#DF> [ 15.310490] <TASK> [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] ... [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] bpf_test_run+0x210/0x370 [ 15.310490] ? bpf_test_run+0x128/0x370 [ 15.310490] bpf_prog_test_run_skb+0x388/0x7a0 [ 15.310490] __sys_bpf+0xdbf/0x2c40 [ 15.310490] ? clockevents_program_event+0x52/0xf0 [ 15.310490] ? lock_release+0xbf/0x290 [ 15.310490] __x64_sys_bpf+0x1e/0x30 [ 15.310490] do_syscall_64+0x68/0x140 [ 15.310490] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 15.310490] RIP: 0033:0x7f133b52725d [ 15.310490] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48 [ 15.310490] RSP: 002b:00007ffddbc10258 EFLAGS: 00000206 ORIG_RAX: 0000000000000141 [ 15.310490] RAX: ffffffffffffffda RBX: 00007ffddbc10828 RCX: 00007f133b52725d [ 15.310490] RDX: 0000000000000050 RSI: 00007ffddbc102a0 RDI: 000000000000000a [ 15.310490] RBP: 00007ffddbc10270 R08: 0000000000000000 R09: 00007ffddbc102a0 [ 15.310490] R10: 0000000000000064 R11: 0000000000000206 R12: 0000000000000004 [ 15.310490] R13: 0000000000000000 R14: 0000558ec4c24890 R15: 00007f133b6ed000 [ 15.310490] </TASK> [ 15.310490] Modules linked in: bpf_testmod(OE) [ 15.310490] ---[ end trace 0000000000000000 ]--- [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Kernel panic - not syncing: Fatal exception in interrupt [ 15.310490] Kernel Offset: 0x30000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) This patch partially prevents this panic by preventing updating extended prog to prog_array map. If a prog or its subprog has been extended by freplace prog, the prog can not be updated to prog_array map. Alongside next patch, the panic will be prevented completely. BTW, fix a minor style issue by replacing 8-spaces with a tab. Signed-off-by: Leon Hwang <leon.hwang@linux.dev>

This patch prevents an infinite loop issue caused by combination of tailcall and freplace. For example: tc_bpf2bpf.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> __noinline int subprog_tc(struct __sk_buff *skb) { return skb->len * 2; } SEC("tc") int entry_tc(struct __sk_buff *skb) { return subprog_tc(skb); } char __license[] SEC("license") = "GPL"; tailcall_freplace.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> struct { __uint(type, BPF_MAP_TYPE_PROG_ARRAY); __uint(max_entries, 1); __uint(key_size, sizeof(__u32)); __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); int count = 0; SEC("freplace") int entry_freplace(struct __sk_buff *skb) { count++; bpf_tail_call_static(skb, &jmp_table, 0); return count; } char __license[] SEC("license") = "GPL"; The attach target of entry_freplace is subprog_tc, and the tail callee in entry_freplace is entry_tc. Then, the infinite loop will be entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc, because tail_call_cnt in entry_freplace will count from zero for every time of entry_freplace execution. Kernel will panic, like: [ 15.310490] BUG: TASK stack guard page was hit at (____ptrval____) (stack is (____ptrval____)..(____ptrval____)) [ 15.310490] Oops: stack guard page: 0000 [#1] PREEMPT SMP NOPTI [ 15.310490] CPU: 1 PID: 89 Comm: test_progs Tainted: G OE 6.10.0-rc6-g026dcdae8d3e-dirty torvalds#72 [ 15.310490] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Call Trace: [ 15.310490] <#DF> [ 15.310490] ? die+0x36/0x90 [ 15.310490] ? handle_stack_overflow+0x4d/0x60 [ 15.310490] ? exc_double_fault+0x117/0x1a0 [ 15.310490] ? asm_exc_double_fault+0x23/0x30 [ 15.310490] ? bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] </#DF> [ 15.310490] <TASK> [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] ... [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] bpf_test_run+0x210/0x370 [ 15.310490] ? bpf_test_run+0x128/0x370 [ 15.310490] bpf_prog_test_run_skb+0x388/0x7a0 [ 15.310490] __sys_bpf+0xdbf/0x2c40 [ 15.310490] ? clockevents_program_event+0x52/0xf0 [ 15.310490] ? lock_release+0xbf/0x290 [ 15.310490] __x64_sys_bpf+0x1e/0x30 [ 15.310490] do_syscall_64+0x68/0x140 [ 15.310490] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 15.310490] RIP: 0033:0x7f133b52725d [ 15.310490] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48 [ 15.310490] RSP: 002b:00007ffddbc10258 EFLAGS: 00000206 ORIG_RAX: 0000000000000141 [ 15.310490] RAX: ffffffffffffffda RBX: 00007ffddbc10828 RCX: 00007f133b52725d [ 15.310490] RDX: 0000000000000050 RSI: 00007ffddbc102a0 RDI: 000000000000000a [ 15.310490] RBP: 00007ffddbc10270 R08: 0000000000000000 R09: 00007ffddbc102a0 [ 15.310490] R10: 0000000000000064 R11: 0000000000000206 R12: 0000000000000004 [ 15.310490] R13: 0000000000000000 R14: 0000558ec4c24890 R15: 00007f133b6ed000 [ 15.310490] </TASK> [ 15.310490] Modules linked in: bpf_testmod(OE) [ 15.310490] ---[ end trace 0000000000000000 ]--- [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Kernel panic - not syncing: Fatal exception in interrupt [ 15.310490] Kernel Offset: 0x30000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) This patch prevents this panic by preventing updating extended prog to prog_array map and preventing extending a prog, which has been updated to prog_array map, with freplace prog. If a prog or its subprog has been extended by freplace prog, the prog can not be updated to prog_array map. If a prog has been updated to prog_array map, it or its subprog can not be extended by freplace prog. BTW, fix a minor code style issue by replacing 8 spaces with a tab. Signed-off-by: Leon Hwang <leon.hwang@linux.dev>

This patch prevents an infinite loop issue caused by combination of tailcall and freplace. For example: tc_bpf2bpf.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> __noinline int subprog_tc(struct __sk_buff *skb) { return skb->len * 2; } SEC("tc") int entry_tc(struct __sk_buff *skb) { return subprog_tc(skb); } char __license[] SEC("license") = "GPL"; tailcall_freplace.c: // SPDX-License-Identifier: GPL-2.0 \#include <linux/bpf.h> \#include <bpf/bpf_helpers.h> struct { __uint(type, BPF_MAP_TYPE_PROG_ARRAY); __uint(max_entries, 1); __uint(key_size, sizeof(__u32)); __uint(value_size, sizeof(__u32)); } jmp_table SEC(".maps"); int count = 0; SEC("freplace") int entry_freplace(struct __sk_buff *skb) { count++; bpf_tail_call_static(skb, &jmp_table, 0); return count; } char __license[] SEC("license") = "GPL"; The attach target of entry_freplace is subprog_tc, and the tail callee in entry_freplace is entry_tc. Then, the infinite loop will be entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc, because tail_call_cnt in entry_freplace will count from zero for every time of entry_freplace execution. Kernel will panic, like: [ 15.310490] BUG: TASK stack guard page was hit at (____ptrval____) (stack is (____ptrval____)..(____ptrval____)) [ 15.310490] Oops: stack guard page: 0000 [#1] PREEMPT SMP NOPTI [ 15.310490] CPU: 1 PID: 89 Comm: test_progs Tainted: G OE 6.10.0-rc6-g026dcdae8d3e-dirty torvalds#72 [ 15.310490] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Call Trace: [ 15.310490] <#DF> [ 15.310490] ? die+0x36/0x90 [ 15.310490] ? handle_stack_overflow+0x4d/0x60 [ 15.310490] ? exc_double_fault+0x117/0x1a0 [ 15.310490] ? asm_exc_double_fault+0x23/0x30 [ 15.310490] ? bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] </#DF> [ 15.310490] <TASK> [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] ... [ 15.310490] bpf_prog_85781a698094722f_entry+0x4c/0x64 [ 15.310490] bpf_prog_1c515f389a9059b4_entry2+0x19/0x1b [ 15.310490] bpf_test_run+0x210/0x370 [ 15.310490] ? bpf_test_run+0x128/0x370 [ 15.310490] bpf_prog_test_run_skb+0x388/0x7a0 [ 15.310490] __sys_bpf+0xdbf/0x2c40 [ 15.310490] ? clockevents_program_event+0x52/0xf0 [ 15.310490] ? lock_release+0xbf/0x290 [ 15.310490] __x64_sys_bpf+0x1e/0x30 [ 15.310490] do_syscall_64+0x68/0x140 [ 15.310490] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 15.310490] RIP: 0033:0x7f133b52725d [ 15.310490] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8b bb 0d 00 f7 d8 64 89 01 48 [ 15.310490] RSP: 002b:00007ffddbc10258 EFLAGS: 00000206 ORIG_RAX: 0000000000000141 [ 15.310490] RAX: ffffffffffffffda RBX: 00007ffddbc10828 RCX: 00007f133b52725d [ 15.310490] RDX: 0000000000000050 RSI: 00007ffddbc102a0 RDI: 000000000000000a [ 15.310490] RBP: 00007ffddbc10270 R08: 0000000000000000 R09: 00007ffddbc102a0 [ 15.310490] R10: 0000000000000064 R11: 0000000000000206 R12: 0000000000000004 [ 15.310490] R13: 0000000000000000 R14: 0000558ec4c24890 R15: 00007f133b6ed000 [ 15.310490] </TASK> [ 15.310490] Modules linked in: bpf_testmod(OE) [ 15.310490] ---[ end trace 0000000000000000 ]--- [ 15.310490] RIP: 0010:bpf_prog_3a140cef239a4b4f_subprog_tail+0x14/0x53 [ 15.310490] Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 0f 1f 00 55 48 89 e5 f3 0f 1e fa <50> 50 53 41 55 48 89 fb 49 bd 00 2a 46 82 98 9c ff ff 48 89 df 4c [ 15.310490] RSP: 0018:ffffb500c0aa0000 EFLAGS: 00000202 [ 15.310490] RAX: ffffb500c0aa0028 RBX: ffff9c98808b7e00 RCX: 0000000000008cb5 [ 15.310490] RDX: 0000000000000000 RSI: ffff9c9882462a00 RDI: ffff9c98808b7e00 [ 15.310490] RBP: ffffb500c0aa0000 R08: 0000000000000000 R09: 0000000000000000 [ 15.310490] R10: 0000000000000001 R11: 0000000000000000 R12: ffffb500c01af000 [ 15.310490] R13: ffffb500c01cd000 R14: 0000000000000000 R15: 0000000000000000 [ 15.310490] FS: 00007f133b665140(0000) GS:ffff9c98bbd00000(0000) knlGS:0000000000000000 [ 15.310490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.310490] CR2: ffffb500c0a9fff8 CR3: 0000000102478000 CR4: 00000000000006f0 [ 15.310490] Kernel panic - not syncing: Fatal exception in interrupt [ 15.310490] Kernel Offset: 0x30000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) This patch prevents this panic by preventing updating extended prog to prog_array map and preventing extending a prog, which has been updated to prog_array map, with freplace prog. If a prog or its subprog has been extended by freplace prog, the prog can not be updated to prog_array map. If a prog has been updated to prog_array map, it or its subprog can not be extended by freplace prog. BTW, fix a minor code style issue by replacing 8 spaces with a tab. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202410080455.vy5GT8Vz-lkp@intel.com/ Signed-off-by: Leon Hwang <leon.hwang@linux.dev>

There are issues(#70, torvalds#72, torvalds#79) with psi support. Removing the support of psi as it doesn't bring much gain.

shanmin added 16 commits January 21, 2014 00:53

Update mach-smartq7.c

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Merge pull request #1 from torvalds/master

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update

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shanmin closed this Feb 21, 2014

hzhuang1 pushed a commit to hzhuang1/linux that referenced this pull request May 22, 2015

Merge pull request torvalds#72 from vishalbhoj/hikey

97cf969

Add UHID config for BT mouse

diaevd referenced this pull request in diaevd/zen-kernel Dec 30, 2015

Merge pull request zen-kernel#72 from johnbeard/master

3e2ccbc

Fix compilation error for kernel version codes < 3.0.0

honjow pushed a commit to 3003n/linux that referenced this pull request Oct 11, 2024

sched/alt: Remove psi support

8a33dfd

There are issues(#70, torvalds#72, torvalds#79) with psi support. Removing the support of psi as it doesn't bring much gain.

honjow pushed a commit to 3003n/linux that referenced this pull request Dec 16, 2024

sched/alt: Remove psi support

813e77f

There are issues(#70, torvalds#72, torvalds#79) with psi support. Removing the support of psi as it doesn't bring much gain.

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3.14-rc3 #72

3.14-rc3 #72

shanmin commented Feb 21, 2014

3.14-rc3 #72

3.14-rc3 #72

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shanmin commented Feb 21, 2014