BUG: fix aliasing UB in scmp_bpf_sim #433
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See seccomp#425. Punning sys_data_b between uint32_t* and struct* seccomp_data isn't legal, use memcpy to fix the testsuite with Clang 17. Modern compilers recognise this idiom and optimise it out anyway. Signed-off-by: Sam James <[email protected]>
pcmoore
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Still experiencing failures with LLVM 17.0.6 https://termbin.com/j2ey |
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I can't reproduce that, I'm afraid. I get failures if I revert my patch, but it passes otherwise. Are you sure it was applied? I also can't see anything obvious that would cause yours if the patch is applied. |
I am 100% the patch is applied, I'm using Nix and it would fail if the patch failed to apply. It said the patch was applied. |
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No idea then, unfortunately. You'll need to try debug it. The full build log could also be useful but I don't see myself able to spend more time on a failure I can't reproduce if it's not caused by my PR, sorry. I suggest starting with object files from a good and bad tree and bisecting via those. |
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Looks reasonable to me. Thanks, @thesamesam
Acked-by: Tom Hromatka <[email protected]>
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Merged via 2847f10, thanks for following through with this fix @thesamesam. If anyone is still seeing failures with this patch applies, please open a new issue so we can debug it further. |
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Thanks all! |
See #425.
Punning sys_data_b between uint32_t* and struct* seccomp_data isn't legal, use memcpy to fix the testsuite with Clang 17.
Modern compilers recognise this idiom and optimise it out anyway.