[PATCH v2 0/2] Stop generating .eh_frame sections

From: Arvind Sankar
Date: Mon Feb 24 2020 - 18:21:55 EST


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.

Changes from v1:

Rebase on top of tip:x86/boot and include reverting the addition of
.eh_frame discard in compressed/vmlinux.lds.S.
Fix up a comment that refers to .eh_frame, pointed out by Nick.

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/compressed/vmlinux.lds.S | 5 -----
arch/x86/boot/setup.ld | 1 -
arch/x86/include/asm/dwarf2.h | 4 ++--
arch/x86/kernel/vmlinux.lds.S | 7 ++-----
arch/x86/realmode/rm/Makefile | 1 +
arch/x86/realmode/rm/realmode.lds.S | 1 -
drivers/firmware/efi/libstub/Makefile | 3 ++-
9 files changed, 9 insertions(+), 15 deletions(-)

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2.24.1