Messages in this thread | | | Date | Sun, 23 Feb 2020 21:15:42 -0700 | From | Nathan Chancellor <> | Subject | Re: [PATCH 0/2] Stop generating .eh_frame sections |
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On Sun, Feb 23, 2020 at 02:37:13PM -0500, Arvind Sankar wrote: > In three places in the x86 kernel we are currently generating .eh_frame > sections only to discard them later via linker script. This is in the > boot code (setup.elf), the realmode trampoline (realmode.elf) and the > compressed kernel. > > Implement Fangrui and Nick's suggestion [1] to fix KBUILD_CFLAGS by > adding -fno-asynchronous-unwind-tables to avoid generating .eh_frame > sections in the first place, rather than discarding it in the linker > script. > > Arvind Sankar (2): > arch/x86: Use -fno-asynchronous-unwind-tables to suppress .eh_frame sections > arch/x86: Drop unneeded linker script discard of .eh_frame > > arch/x86/boot/Makefile | 1 + > arch/x86/boot/compressed/Makefile | 1 + > arch/x86/boot/setup.ld | 1 - > arch/x86/kernel/vmlinux.lds.S | 3 --- > arch/x86/realmode/rm/Makefile | 1 + > arch/x86/realmode/rm/realmode.lds.S | 1 - > drivers/firmware/efi/libstub/Makefile | 3 ++- > 7 files changed, 5 insertions(+), 6 deletions(-) > > -- > 2.24.1 >
With both of these patches applied on top of next-20200221 and a revert of commit e11831d0ada3 ("x86/boot/compressed: Remove unnecessary sections from bzImage"), I do not see any .eh_frame sections in the following files:
$ readelf -S arch/x86/boot/setup.elf \ arch/x86/realmode/rm/realmode.elf \ arch/x86/boot/compressed/vmlinux \ vmlinux |& grep eh_frame
Additionally, I can see -fno-asynchronous-unwind-tables get added to files that didn't previously have it.
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
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