Messages in this thread | | | Date | Thu, 25 Feb 2021 12:28:21 -0700 | From | Nathan Chancellor <> | Subject | Re: [PATCH v3] vmlinux.lds.h: Define SANTIZER_DISCARDS with CONFIG_GCOV_KERNEL=y |
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On Fri, Jan 29, 2021 at 05:46:51PM -0700, Nathan Chancellor wrote: > clang produces .eh_frame sections when CONFIG_GCOV_KERNEL is enabled, > even when -fno-asynchronous-unwind-tables is in KBUILD_CFLAGS: > > $ make CC=clang vmlinux > ... > ld: warning: orphan section `.eh_frame' from `init/main.o' being placed in section `.eh_frame' > ld: warning: orphan section `.eh_frame' from `init/version.o' being placed in section `.eh_frame' > ld: warning: orphan section `.eh_frame' from `init/do_mounts.o' being placed in section `.eh_frame' > ld: warning: orphan section `.eh_frame' from `init/do_mounts_initrd.o' being placed in section `.eh_frame' > ld: warning: orphan section `.eh_frame' from `init/initramfs.o' being placed in section `.eh_frame' > ld: warning: orphan section `.eh_frame' from `init/calibrate.o' being placed in section `.eh_frame' > ld: warning: orphan section `.eh_frame' from `init/init_task.o' being placed in section `.eh_frame' > ... > > $ rg "GCOV_KERNEL|GCOV_PROFILE_ALL" .config > CONFIG_GCOV_KERNEL=y > CONFIG_ARCH_HAS_GCOV_PROFILE_ALL=y > CONFIG_GCOV_PROFILE_ALL=y > > This was already handled for a couple of other options in > commit d812db78288d ("vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted > sections") and there is an open LLVM bug for this issue. Take advantage > of that section for this config as well so that there are no more orphan > warnings. > > Link: https://bugs.llvm.org/show_bug.cgi?id=46478 > Link: https://github.com/ClangBuiltLinux/linux/issues/1069 > Reported-by: kernel test robot <lkp@intel.com> > Reviewed-by: Fangrui Song <maskray@google.com> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Nathan Chancellor <nathan@kernel.org> > --- > > v2 -> v3: > > * Fix double "unwanted" in comment section per Sedat. > > v1 -> v2: > > * Keep configs and flag names alphabetized. > > * Drop mention of -ftest-coverage since it does not cause this issue per > Fangrui. > > * Pick up review tags from Fangrui and Nick. > > include/asm-generic/vmlinux.lds.h | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > index b2b3d81b1535..b61b537177fb 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -988,12 +988,13 @@ > #endif > > /* > - * Clang's -fsanitize=kernel-address and -fsanitize=thread produce > - * unwanted sections (.eh_frame and .init_array.*), but > - * CONFIG_CONSTRUCTORS wants to keep any .init_array.* sections. > + * Clang's -fprofile-arcs, -fsanitize=kernel-address, and > + * -fsanitize=thread produce unwanted sections (.eh_frame > + * and .init_array.*), but CONFIG_CONSTRUCTORS wants to > + * keep any .init_array.* sections. > * https://bugs.llvm.org/show_bug.cgi?id=46478 > */ > -#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN) > +#if defined(CONFIG_GCOV_KERNEL) || defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN) > # ifdef CONFIG_CONSTRUCTORS > # define SANITIZER_DISCARDS \ > *(.eh_frame) > > base-commit: bec4c2968fce2f44ce62d05288a633cd99a722eb > -- > 2.30.0 >
Andrew, Arnd, or Kees:
Would one of you be able to pick this up and get it to Linus? I think the 0day bot just tripped over this again:
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/message/BXBY7OPVMOCCUZSCFEZXI7RG65RJWJ52/ https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/message/QF62LWM6YSNWWNOM7AXYK4734AKH2SVT/
Cheers, Nathan
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