config request CONFIG_NETFILTER_NETLINK_LOG #182
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This is included in recent firmwares: |
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Thanks a lot, works perfectly :-) |
popcornmix
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Jan 22, 2014
Even if user doesn't supply the physical netdev to attach vxlan dev to, and at the same time user want to vxlan sit top of IPv6, mark vxlan_dev flags with VXLAN_F_IPV6 to create IPv6 based socket. Otherwise kernel crashes safely every time spitting below messages, Steps to reproduce: ip link add vxlan0 type vxlan id 42 group ff0e::110 ip link set vxlan0 up [ 62.656266] BUG: unable to handle kernel NULL pointer dereference[ 62.656320] ip (3008) used greatest stack depth: 3912 bytes left at 0000000000000046 [ 62.656423] IP: [<ffffffff816d822d>] ip6_route_output+0xbd/0xe0 [ 62.656525] PGD 2c966067 PUD 2c9a2067 PMD 0 [ 62.656674] Oops: 0000 [#1] SMP [ 62.656781] Modules linked in: vxlan netconsole deflate zlib_deflate af_key [ 62.657083] CPU: 1 PID: 2128 Comm: whoopsie Not tainted 3.12.0+ #182 [ 62.657083] Hardware name: innotek GmbH VirtualBox, BIOS VirtualBox 12/01/2006 [ 62.657083] task: ffff88002e2335d0 ti: ffff88002c94c000 task.ti: ffff88002c94c000 [ 62.657083] RIP: 0010:[<ffffffff816d822d>] [<ffffffff816d822d>] ip6_route_output+0xbd/0xe0 [ 62.657083] RSP: 0000:ffff88002fd038f8 EFLAGS: 00210296 [ 62.657083] RAX: 0000000000000000 RBX: ffff88002fd039e0 RCX: 0000000000000000 [ 62.657083] RDX: ffff88002fd0eb68 RSI: ffff88002fd0d278 RDI: ffff88002fd0d278 [ 62.657083] RBP: ffff88002fd03918 R08: 0000000002000000 R09: 0000000000000000 [ 62.657083] R10: 00000000000001ff R11: 0000000000000000 R12: 0000000000000001 [ 62.657083] R13: ffff88002d96b480 R14: ffffffff81c8e2c0 R15: 0000000000000001 [ 62.657083] FS: 0000000000000000(0000) GS:ffff88002fd00000(0063) knlGS:00000000f693b740 [ 62.657083] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 62.657083] CR2: 0000000000000046 CR3: 000000002c9d2000 CR4: 00000000000006e0 [ 62.657083] Stack: [ 62.657083] ffff88002fd03a40 ffffffff81c8e2c0 ffff88002fd039e0 ffff88002d96b480 [ 62.657083] ffff88002fd03958 ffffffff816cac8b ffff880019277cc0 ffff8800192b5d00 [ 62.657083] ffff88002d5bc000 ffff880019277cc0 0000000000001821 0000000000000001 [ 62.657083] Call Trace: [ 62.657083] <IRQ> [ 62.657083] [<ffffffff816cac8b>] ip6_dst_lookup_tail+0xdb/0xf0 [ 62.657083] [<ffffffff816caea0>] ip6_dst_lookup+0x10/0x20 [ 62.657083] [<ffffffffa0020c13>] vxlan_xmit_one+0x193/0x9c0 [vxlan] [ 62.657083] [<ffffffff8137b3b7>] ? account+0xc7/0x1f0 [ 62.657083] [<ffffffffa0021513>] vxlan_xmit+0xd3/0x400 [vxlan] [ 62.657083] [<ffffffff8161390d>] dev_hard_start_xmit+0x49d/0x5e0 [ 62.657083] [<ffffffff81613d29>] dev_queue_xmit+0x2d9/0x480 [ 62.657083] [<ffffffff817cb854>] ? _raw_write_unlock_bh+0x14/0x20 [ 62.657083] [<ffffffff81630565>] ? eth_header+0x35/0xe0 [ 62.657083] [<ffffffff8161bc5e>] neigh_resolve_output+0x11e/0x1e0 [ 62.657083] [<ffffffff816ce0e0>] ? ip6_fragment+0xad0/0xad0 [ 62.657083] [<ffffffff816cb465>] ip6_finish_output2+0x2f5/0x470 [ 62.657083] [<ffffffff816ce166>] ip6_finish_output+0x86/0xc0 [ 62.657083] [<ffffffff816ce218>] ip6_output+0x78/0xb0 [ 62.657083] [<ffffffff816eadd6>] mld_sendpack+0x256/0x2a0 [ 62.657083] [<ffffffff816ebd8c>] mld_ifc_timer_expire+0x17c/0x290 [ 62.657083] [<ffffffff816ebc10>] ? igmp6_timer_handler+0x80/0x80 [ 62.657083] [<ffffffff816ebc10>] ? igmp6_timer_handler+0x80/0x80 [ 62.657083] [<ffffffff81051065>] call_timer_fn+0x45/0x150 [ 62.657083] [<ffffffff816ebc10>] ? igmp6_timer_handler+0x80/0x80 [ 62.657083] [<ffffffff81052353>] run_timer_softirq+0x1f3/0x2a0 [ 62.657083] [<ffffffff8102dfd8>] ? lapic_next_event+0x18/0x20 [ 62.657083] [<ffffffff8109e36f>] ? clockevents_program_event+0x6f/0x110 [ 62.657083] [<ffffffff8104a2f6>] __do_softirq+0xd6/0x2b0 [ 62.657083] [<ffffffff8104a75e>] irq_exit+0x7e/0xa0 [ 62.657083] [<ffffffff8102ea15>] smp_apic_timer_interrupt+0x45/0x60 [ 62.657083] [<ffffffff817d3eca>] apic_timer_interrupt+0x6a/0x70 [ 62.657083] <EOI> [ 62.657083] [<ffffffff817d4a35>] ? sysenter_dispatch+0x7/0x1a [ 62.657083] Code: 4d 8b 85 a8 02 00 00 4c 89 e9 ba 03 04 00 00 48 c7 c6 c0 be 8d 81 48 c7 c7 48 35 a3 81 31 c0 e8 db 68 0e 00 49 8b 85 a8 02 00 00 <0f> b6 40 46 c0 e8 05 0f b6 c0 c1 e0 03 41 09 c4 e9 77 ff ff ff [ 62.657083] RIP [<ffffffff816d822d>] ip6_route_output+0xbd/0xe0 [ 62.657083] RSP <ffff88002fd038f8> [ 62.657083] CR2: 0000000000000046 [ 62.657083] ---[ end trace ba8a9583d7cd1934 ]--- [ 62.657083] Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: Fan Du <fan.du@windriver.com> Reported-by: Ryan Whelan <rcwhelan@gmail.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
anholt
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Jul 18, 2015
dma_unmap_sg() is being called twice after completing the task. Looks like this is a copy paste error when creating des driver. With this the following warn appears during boot: [ 4.210457] ------------[ cut here ]------------ [ 4.215114] WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1080 check_unmap+0x710/0x9a0() [ 4.222899] omap-des 480a5000.des: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x00000000ab2ce000] [size=8 bytes] [ 4.236785] Modules linked in: [ 4.239860] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.39-02999-g1bc045a-dirty raspberrypi#182 [ 4.247918] [<c001678c>] (unwind_backtrace) from [<c0012574>] (show_stack+0x10/0x14) [ 4.255710] [<c0012574>] (show_stack) from [<c05a37e8>] (dump_stack+0x84/0xb8) [ 4.262977] [<c05a37e8>] (dump_stack) from [<c0046464>] (warn_slowpath_common+0x68/0x8c) [ 4.271107] [<c0046464>] (warn_slowpath_common) from [<c004651c>] (warn_slowpath_fmt+0x30/0x40) [ 4.279854] [<c004651c>] (warn_slowpath_fmt) from [<c02d50a4>] (check_unmap+0x710/0x9a0) [ 4.287991] [<c02d50a4>] (check_unmap) from [<c02d5478>] (debug_dma_unmap_sg+0x90/0x19c) [ 4.296128] [<c02d5478>] (debug_dma_unmap_sg) from [<c04a77d8>] (omap_des_done_task+0x1cc/0x3e4) [ 4.304963] [<c04a77d8>] (omap_des_done_task) from [<c004a090>] (tasklet_action+0x84/0x124) [ 4.313370] [<c004a090>] (tasklet_action) from [<c004a4ac>] (__do_softirq+0xf0/0x20c) [ 4.321235] [<c004a4ac>] (__do_softirq) from [<c004a840>] (irq_exit+0x98/0xec) [ 4.328500] [<c004a840>] (irq_exit) from [<c000f9ac>] (handle_IRQ+0x50/0xb0) [ 4.335589] [<c000f9ac>] (handle_IRQ) from [<c0008688>] (gic_handle_irq+0x28/0x5c) Removing the duplicate call to dma_unmap_sg(). Cc: stable@vger.kernel.org Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
popcornmix
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Aug 12, 2015
commit acb33cc upstream. dma_unmap_sg() is being called twice after completing the task. Looks like this is a copy paste error when creating des driver. With this the following warn appears during boot: [ 4.210457] ------------[ cut here ]------------ [ 4.215114] WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1080 check_unmap+0x710/0x9a0() [ 4.222899] omap-des 480a5000.des: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x00000000ab2ce000] [size=8 bytes] [ 4.236785] Modules linked in: [ 4.239860] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.14.39-02999-g1bc045a-dirty #182 [ 4.247918] [<c001678c>] (unwind_backtrace) from [<c0012574>] (show_stack+0x10/0x14) [ 4.255710] [<c0012574>] (show_stack) from [<c05a37e8>] (dump_stack+0x84/0xb8) [ 4.262977] [<c05a37e8>] (dump_stack) from [<c0046464>] (warn_slowpath_common+0x68/0x8c) [ 4.271107] [<c0046464>] (warn_slowpath_common) from [<c004651c>] (warn_slowpath_fmt+0x30/0x40) [ 4.279854] [<c004651c>] (warn_slowpath_fmt) from [<c02d50a4>] (check_unmap+0x710/0x9a0) [ 4.287991] [<c02d50a4>] (check_unmap) from [<c02d5478>] (debug_dma_unmap_sg+0x90/0x19c) [ 4.296128] [<c02d5478>] (debug_dma_unmap_sg) from [<c04a77d8>] (omap_des_done_task+0x1cc/0x3e4) [ 4.304963] [<c04a77d8>] (omap_des_done_task) from [<c004a090>] (tasklet_action+0x84/0x124) [ 4.313370] [<c004a090>] (tasklet_action) from [<c004a4ac>] (__do_softirq+0xf0/0x20c) [ 4.321235] [<c004a4ac>] (__do_softirq) from [<c004a840>] (irq_exit+0x98/0xec) [ 4.328500] [<c004a840>] (irq_exit) from [<c000f9ac>] (handle_IRQ+0x50/0xb0) [ 4.335589] [<c000f9ac>] (handle_IRQ) from [<c0008688>] (gic_handle_irq+0x28/0x5c) Removing the duplicate call to dma_unmap_sg(). Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
popcornmix
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May 19, 2021
[ Upstream commit 0f20615 ] Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable bitfields. Missing breaks in a switch caused 8-byte reads always. This can confuse libbpf because it does strict checks that memory load size corresponds to the original size of the field, which in this case quite often would be wrong. After fixing that, we run into another problem, which quite subtle, so worth documenting here. The issue is in Clang optimization and CO-RE relocation interactions. Without that asm volatile construct (also known as barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and will apply BYTE_OFFSET 4 times for each switch case arm. This will result in the same error from libbpf about mismatch of memory load size and original field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *), *(u32 *), and *(u64 *) memory loads, three of which will fail. Using barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to calculate p, after which value of p is used without relocation in each of switch case arms, doing appropiately-sized memory load. Here's the list of relevant relocations and pieces of generated BPF code before and after this patch for test_core_reloc_bitfields_direct selftests. BEFORE ===== #45: core_reloc: insn #160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 #46: core_reloc: insn #167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #47: core_reloc: insn #174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #48: core_reloc: insn #178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #49: core_reloc: insn #182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 157: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 159: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 160: b7 02 00 00 04 00 00 00 r2 = 4 ; BYTE_SIZE relocation here ^^^ 161: 66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63> 162: 16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65> 163: 16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66> 164: 05 00 12 00 00 00 00 00 goto +18 <LBB0_69> 0000000000000528 <LBB0_66>: 165: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 167: 69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 168: 05 00 0e 00 00 00 00 00 goto +14 <LBB0_69> 0000000000000548 <LBB0_63>: 169: 16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67> 170: 16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68> 171: 05 00 0b 00 00 00 00 00 goto +11 <LBB0_69> 0000000000000560 <LBB0_68>: 172: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 174: 79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 175: 05 00 07 00 00 00 00 00 goto +7 <LBB0_69> 0000000000000580 <LBB0_65>: 176: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 178: 71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 179: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 00000000000005a0 <LBB0_67>: 180: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 182: 61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8) ; BYTE_OFFSET relo here w/ RIGHT size ^^^^^^^^^^^^^^^^ 00000000000005b8 <LBB0_69>: 183: 67 01 00 00 20 00 00 00 r1 <<= 32 184: b7 02 00 00 00 00 00 00 r2 = 0 185: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 186: c7 01 00 00 20 00 00 00 r1 s>>= 32 187: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000005e0 <LBB0_71>: 188: 77 01 00 00 20 00 00 00 r1 >>= 32 AFTER ===== #30: core_reloc: insn #132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #31: core_reloc: insn #134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 129: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 131: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 132: b7 01 00 00 08 00 00 00 r1 = 8 ; BYTE_OFFSET relo here ^^^ ; no size check for non-memory dereferencing instructions 133: 0f 12 00 00 00 00 00 00 r2 += r1 134: b7 03 00 00 04 00 00 00 r3 = 4 ; BYTE_SIZE relocation here ^^^ 135: 66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63> 136: 16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65> 137: 16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66> 138: 05 00 0a 00 00 00 00 00 goto +10 <LBB0_69> 0000000000000458 <LBB0_66>: 139: 69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 140: 05 00 08 00 00 00 00 00 goto +8 <LBB0_69> 0000000000000468 <LBB0_63>: 141: 16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67> 142: 16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68> 143: 05 00 05 00 00 00 00 00 goto +5 <LBB0_69> 0000000000000480 <LBB0_68>: 144: 79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 145: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 0000000000000490 <LBB0_65>: 146: 71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 147: 05 00 01 00 00 00 00 00 goto +1 <LBB0_69> 00000000000004a0 <LBB0_67>: 148: 61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 00000000000004a8 <LBB0_69>: 149: 67 01 00 00 20 00 00 00 r1 <<= 32 150: b7 02 00 00 00 00 00 00 r2 = 0 151: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 152: c7 01 00 00 20 00 00 00 r1 s>>= 32 153: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000004d0 <LBB0_71>: 154: 77 01 00 00 20 00 00 00 r1 >>= 323 Fixes: ee26dad ("libbpf: Add support for relocatable bitfields") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Lorenz Bauer <lmb@cloudflare.com> Link: https://lore.kernel.org/bpf/20210426192949.416837-4-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix
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May 19, 2021
[ Upstream commit 0f20615 ] Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable bitfields. Missing breaks in a switch caused 8-byte reads always. This can confuse libbpf because it does strict checks that memory load size corresponds to the original size of the field, which in this case quite often would be wrong. After fixing that, we run into another problem, which quite subtle, so worth documenting here. The issue is in Clang optimization and CO-RE relocation interactions. Without that asm volatile construct (also known as barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and will apply BYTE_OFFSET 4 times for each switch case arm. This will result in the same error from libbpf about mismatch of memory load size and original field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *), *(u32 *), and *(u64 *) memory loads, three of which will fail. Using barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to calculate p, after which value of p is used without relocation in each of switch case arms, doing appropiately-sized memory load. Here's the list of relevant relocations and pieces of generated BPF code before and after this patch for test_core_reloc_bitfields_direct selftests. BEFORE ===== #45: core_reloc: insn #160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 #46: core_reloc: insn #167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #47: core_reloc: insn #174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #48: core_reloc: insn #178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #49: core_reloc: insn #182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 157: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 159: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 160: b7 02 00 00 04 00 00 00 r2 = 4 ; BYTE_SIZE relocation here ^^^ 161: 66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63> 162: 16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65> 163: 16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66> 164: 05 00 12 00 00 00 00 00 goto +18 <LBB0_69> 0000000000000528 <LBB0_66>: 165: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 167: 69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 168: 05 00 0e 00 00 00 00 00 goto +14 <LBB0_69> 0000000000000548 <LBB0_63>: 169: 16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67> 170: 16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68> 171: 05 00 0b 00 00 00 00 00 goto +11 <LBB0_69> 0000000000000560 <LBB0_68>: 172: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 174: 79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 175: 05 00 07 00 00 00 00 00 goto +7 <LBB0_69> 0000000000000580 <LBB0_65>: 176: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 178: 71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 179: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 00000000000005a0 <LBB0_67>: 180: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 182: 61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8) ; BYTE_OFFSET relo here w/ RIGHT size ^^^^^^^^^^^^^^^^ 00000000000005b8 <LBB0_69>: 183: 67 01 00 00 20 00 00 00 r1 <<= 32 184: b7 02 00 00 00 00 00 00 r2 = 0 185: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 186: c7 01 00 00 20 00 00 00 r1 s>>= 32 187: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000005e0 <LBB0_71>: 188: 77 01 00 00 20 00 00 00 r1 >>= 32 AFTER ===== #30: core_reloc: insn #132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #31: core_reloc: insn #134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 129: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 131: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 132: b7 01 00 00 08 00 00 00 r1 = 8 ; BYTE_OFFSET relo here ^^^ ; no size check for non-memory dereferencing instructions 133: 0f 12 00 00 00 00 00 00 r2 += r1 134: b7 03 00 00 04 00 00 00 r3 = 4 ; BYTE_SIZE relocation here ^^^ 135: 66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63> 136: 16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65> 137: 16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66> 138: 05 00 0a 00 00 00 00 00 goto +10 <LBB0_69> 0000000000000458 <LBB0_66>: 139: 69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 140: 05 00 08 00 00 00 00 00 goto +8 <LBB0_69> 0000000000000468 <LBB0_63>: 141: 16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67> 142: 16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68> 143: 05 00 05 00 00 00 00 00 goto +5 <LBB0_69> 0000000000000480 <LBB0_68>: 144: 79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 145: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 0000000000000490 <LBB0_65>: 146: 71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 147: 05 00 01 00 00 00 00 00 goto +1 <LBB0_69> 00000000000004a0 <LBB0_67>: 148: 61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 00000000000004a8 <LBB0_69>: 149: 67 01 00 00 20 00 00 00 r1 <<= 32 150: b7 02 00 00 00 00 00 00 r2 = 0 151: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 152: c7 01 00 00 20 00 00 00 r1 s>>= 32 153: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000004d0 <LBB0_71>: 154: 77 01 00 00 20 00 00 00 r1 >>= 323 Fixes: ee26dad ("libbpf: Add support for relocatable bitfields") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Lorenz Bauer <lmb@cloudflare.com> Link: https://lore.kernel.org/bpf/20210426192949.416837-4-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
popcornmix
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May 19, 2021
[ Upstream commit 0f20615 ] Fix BPF_CORE_READ_BITFIELD() macro used for reading CO-RE-relocatable bitfields. Missing breaks in a switch caused 8-byte reads always. This can confuse libbpf because it does strict checks that memory load size corresponds to the original size of the field, which in this case quite often would be wrong. After fixing that, we run into another problem, which quite subtle, so worth documenting here. The issue is in Clang optimization and CO-RE relocation interactions. Without that asm volatile construct (also known as barrier_var()), Clang will re-order BYTE_OFFSET and BYTE_SIZE relocations and will apply BYTE_OFFSET 4 times for each switch case arm. This will result in the same error from libbpf about mismatch of memory load size and original field size. I.e., if we were reading u32, we'd still have *(u8 *), *(u16 *), *(u32 *), and *(u64 *) memory loads, three of which will fail. Using barrier_var() forces Clang to apply BYTE_OFFSET relocation first (and once) to calculate p, after which value of p is used without relocation in each of switch case arms, doing appropiately-sized memory load. Here's the list of relevant relocations and pieces of generated BPF code before and after this patch for test_core_reloc_bitfields_direct selftests. BEFORE ===== #45: core_reloc: insn #160 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 #46: core_reloc: insn #167 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #47: core_reloc: insn #174 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #48: core_reloc: insn #178 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #49: core_reloc: insn #182 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 157: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 159: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 160: b7 02 00 00 04 00 00 00 r2 = 4 ; BYTE_SIZE relocation here ^^^ 161: 66 02 07 00 03 00 00 00 if w2 s> 3 goto +7 <LBB0_63> 162: 16 02 0d 00 01 00 00 00 if w2 == 1 goto +13 <LBB0_65> 163: 16 02 01 00 02 00 00 00 if w2 == 2 goto +1 <LBB0_66> 164: 05 00 12 00 00 00 00 00 goto +18 <LBB0_69> 0000000000000528 <LBB0_66>: 165: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 167: 69 11 08 00 00 00 00 00 r1 = *(u16 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 168: 05 00 0e 00 00 00 00 00 goto +14 <LBB0_69> 0000000000000548 <LBB0_63>: 169: 16 02 0a 00 04 00 00 00 if w2 == 4 goto +10 <LBB0_67> 170: 16 02 01 00 08 00 00 00 if w2 == 8 goto +1 <LBB0_68> 171: 05 00 0b 00 00 00 00 00 goto +11 <LBB0_69> 0000000000000560 <LBB0_68>: 172: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 174: 79 11 08 00 00 00 00 00 r1 = *(u64 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 175: 05 00 07 00 00 00 00 00 goto +7 <LBB0_69> 0000000000000580 <LBB0_65>: 176: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 178: 71 11 08 00 00 00 00 00 r1 = *(u8 *)(r1 + 8) ; BYTE_OFFSET relo here w/ WRONG size ^^^^^^^^^^^^^^^^ 179: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 00000000000005a0 <LBB0_67>: 180: 18 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r1 = 0 ll 182: 61 11 08 00 00 00 00 00 r1 = *(u32 *)(r1 + 8) ; BYTE_OFFSET relo here w/ RIGHT size ^^^^^^^^^^^^^^^^ 00000000000005b8 <LBB0_69>: 183: 67 01 00 00 20 00 00 00 r1 <<= 32 184: b7 02 00 00 00 00 00 00 r2 = 0 185: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 186: c7 01 00 00 20 00 00 00 r1 s>>= 32 187: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000005e0 <LBB0_71>: 188: 77 01 00 00 20 00 00 00 r1 >>= 32 AFTER ===== #30: core_reloc: insn #132 --> [5] + 0:5: byte_off --> struct core_reloc_bitfields.u32 #31: core_reloc: insn #134 --> [5] + 0:5: byte_sz --> struct core_reloc_bitfields.u32 129: 18 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 r2 = 0 ll 131: 7b 12 20 01 00 00 00 00 *(u64 *)(r2 + 288) = r1 132: b7 01 00 00 08 00 00 00 r1 = 8 ; BYTE_OFFSET relo here ^^^ ; no size check for non-memory dereferencing instructions 133: 0f 12 00 00 00 00 00 00 r2 += r1 134: b7 03 00 00 04 00 00 00 r3 = 4 ; BYTE_SIZE relocation here ^^^ 135: 66 03 05 00 03 00 00 00 if w3 s> 3 goto +5 <LBB0_63> 136: 16 03 09 00 01 00 00 00 if w3 == 1 goto +9 <LBB0_65> 137: 16 03 01 00 02 00 00 00 if w3 == 2 goto +1 <LBB0_66> 138: 05 00 0a 00 00 00 00 00 goto +10 <LBB0_69> 0000000000000458 <LBB0_66>: 139: 69 21 00 00 00 00 00 00 r1 = *(u16 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 140: 05 00 08 00 00 00 00 00 goto +8 <LBB0_69> 0000000000000468 <LBB0_63>: 141: 16 03 06 00 04 00 00 00 if w3 == 4 goto +6 <LBB0_67> 142: 16 03 01 00 08 00 00 00 if w3 == 8 goto +1 <LBB0_68> 143: 05 00 05 00 00 00 00 00 goto +5 <LBB0_69> 0000000000000480 <LBB0_68>: 144: 79 21 00 00 00 00 00 00 r1 = *(u64 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 145: 05 00 03 00 00 00 00 00 goto +3 <LBB0_69> 0000000000000490 <LBB0_65>: 146: 71 21 00 00 00 00 00 00 r1 = *(u8 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 147: 05 00 01 00 00 00 00 00 goto +1 <LBB0_69> 00000000000004a0 <LBB0_67>: 148: 61 21 00 00 00 00 00 00 r1 = *(u32 *)(r2 + 0) ; NO CO-RE relocation here ^^^^^^^^^^^^^^^^ 00000000000004a8 <LBB0_69>: 149: 67 01 00 00 20 00 00 00 r1 <<= 32 150: b7 02 00 00 00 00 00 00 r2 = 0 151: 16 02 02 00 00 00 00 00 if w2 == 0 goto +2 <LBB0_71> 152: c7 01 00 00 20 00 00 00 r1 s>>= 32 153: 05 00 01 00 00 00 00 00 goto +1 <LBB0_72> 00000000000004d0 <LBB0_71>: 154: 77 01 00 00 20 00 00 00 r1 >>= 323 Fixes: ee26dad ("libbpf: Add support for relocatable bitfields") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Lorenz Bauer <lmb@cloudflare.com> Link: https://lore.kernel.org/bpf/20210426192949.416837-4-andrii@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
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Hello,
I want to have a simple firewall with some logging to syslog.
Can you please add the module for xt_LOG by adding CONFIG_NETFILTER_NETLINK_LOG=m?
ulogd is not appropriate for me as
Beside almost any other netfilter related module is there, so I assume it was just overlooked.
Thanks for including it.
Bye,
Joerg
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