yonghong-song added a comment. @compnerd could you also take a look at this patch?
First, some background about this patch. The reason of this patch is due to: https://lore.kernel.org/bpf/CAOFdcFPnHEc2qd-=c+hdk4ntjjfbhsf4r-g7pdjtrbat6mu...@mail.gmail.com/ Further the following link has details about hardened gentoo and modified clang default flags: https://wiki.gentoo.org/wiki/Hardened_Gentoo Unfortunately, we don't want -fstack-protector for bpf target as bpf kernel verifier will do stack verification. This patch tries to ignore -fstack-protector. NVPTX arch has the same need of ignoring -fstack-protector. This patch presented a different message than NVPTX. This patch: clang-16: warning: ignoring '-fstack-protector' option as it is not currently supported for target 'bpf' [-Woption-ignored] NVPTX clang-16: warning: argument unused during compilation: '-fstack-protector' [-Wunused-command-line-argument] Does clang community has a preference for the above two formats? Let us say we do implement this patch and merged into clang, then using gentoo clang compiler, we will hit the warning: clang-16: warning: ignoring '-fstack-protector' option as it is not currently supported for target 'bpf' [-Woption-ignored] I suspect gentoo community might complain. I don't think we should add -Wno-option-ignored since this may cause unintended issues with compiler command line arguments. Without -Wno-option-ignored, gentoo community might wants to append -fno-stack-protector to disable stack-protector, but with the current implementation, we might actually trigger another warning. So we have to two choices here for bpf target: (1). ignore any stack-protector option and do not issue any warning, or (2). append -fno-stack-protector by clang to compilation flags. We can document this behavior in related clang (and kernel) docs. WDYT? WDYT? Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D142046/new/ https://reviews.llvm.org/D142046 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
