bpf: Fix the irq and nmi check in bpf_sk_storage for tracing usage #356
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The intention of the current check is to avoid using bpf_sk_storage in irq and nmi. Jakub pointed out that the current check cannot do that. For example, in_serving_softirq() returns true if the softirq handling is interrupted by hard irq. Fixes: 8e4597c ("bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP") Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Martin KaFai Lau <kafai@fb.com>
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Master branch: 024cd2c |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=385417 irrelevant now. Closing PR. |
kernel-patches-daemon-bpf bot
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With latest upstream llvm18, the following test cases failed: $ ./test_progs -j #13/2 bpf_cookie/multi_kprobe_link_api:FAIL #13/3 bpf_cookie/multi_kprobe_attach_api:FAIL #13 bpf_cookie:FAIL #77 fentry_fexit:FAIL #78/1 fentry_test/fentry:FAIL #78 fentry_test:FAIL #82/1 fexit_test/fexit:FAIL #82 fexit_test:FAIL #112/1 kprobe_multi_test/skel_api:FAIL #112/2 kprobe_multi_test/link_api_addrs:FAIL ... #112 kprobe_multi_test:FAIL #356/17 test_global_funcs/global_func17:FAIL #356 test_global_funcs:FAIL Further analysis shows llvm upstream patch [1] is responsible for the above failures. For example, for function bpf_fentry_test7() in net/bpf/test_run.c, without [1], the asm code is: 0000000000000400 <bpf_fentry_test7>: 400: f3 0f 1e fa endbr64 404: e8 00 00 00 00 callq 0x409 <bpf_fentry_test7+0x9> 409: 48 89 f8 movq %rdi, %rax 40c: c3 retq 40d: 0f 1f 00 nopl (%rax) and with [1], the asm code is: 0000000000005d20 <bpf_fentry_test7.specialized.1>: 5d20: e8 00 00 00 00 callq 0x5d25 <bpf_fentry_test7.specialized.1+0x5> 5d25: c3 retq and <bpf_fentry_test7.specialized.1> is called instead of <bpf_fentry_test7> and this caused test failures for #13/#77 etc. except #356. For test case #356/17, with [1] (progs/test_global_func17.c)), the main prog looks like: 0000000000000000 <global_func17>: 0: b4 00 00 00 2a 00 00 00 w0 = 0x2a 1: 95 00 00 00 00 00 00 00 exit which passed verification while the test itself expects a verification failure. Let us add 'barrier_var' style asm code in both places to prevent function specialization which caused selftests failure. [1] llvm/llvm-project#72903 Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
kernel-patches-daemon-bpf bot
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Nov 27, 2023
With latest upstream llvm18, the following test cases failed: $ ./test_progs -j #13/2 bpf_cookie/multi_kprobe_link_api:FAIL #13/3 bpf_cookie/multi_kprobe_attach_api:FAIL #13 bpf_cookie:FAIL #77 fentry_fexit:FAIL #78/1 fentry_test/fentry:FAIL #78 fentry_test:FAIL #82/1 fexit_test/fexit:FAIL #82 fexit_test:FAIL #112/1 kprobe_multi_test/skel_api:FAIL #112/2 kprobe_multi_test/link_api_addrs:FAIL [...] #112 kprobe_multi_test:FAIL #356/17 test_global_funcs/global_func17:FAIL #356 test_global_funcs:FAIL Further analysis shows llvm upstream patch [1] is responsible for the above failures. For example, for function bpf_fentry_test7() in net/bpf/test_run.c, without [1], the asm code is: 0000000000000400 <bpf_fentry_test7>: 400: f3 0f 1e fa endbr64 404: e8 00 00 00 00 callq 0x409 <bpf_fentry_test7+0x9> 409: 48 89 f8 movq %rdi, %rax 40c: c3 retq 40d: 0f 1f 00 nopl (%rax) ... and with [1], the asm code is: 0000000000005d20 <bpf_fentry_test7.specialized.1>: 5d20: e8 00 00 00 00 callq 0x5d25 <bpf_fentry_test7.specialized.1+0x5> 5d25: c3 retq ... and <bpf_fentry_test7.specialized.1> is called instead of <bpf_fentry_test7> and this caused test failures for #13/#77 etc. except #356. For test case #356/17, with [1] (progs/test_global_func17.c)), the main prog looks like: 0000000000000000 <global_func17>: 0: b4 00 00 00 2a 00 00 00 w0 = 0x2a 1: 95 00 00 00 00 00 00 00 exit ... which passed verification while the test itself expects a verification failure. Let us add 'barrier_var' style asm code in both places to prevent function specialization which caused selftests failure. [1] llvm/llvm-project#72903 Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20231127050342.1945270-1-yonghong.song@linux.dev
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Pull request for series with
subject: bpf: Fix the irq and nmi check in bpf_sk_storage for tracing usage
version: 1
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=385417