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| author | Arvind Sankar <nivedita@alum.mit.edu> | 2020-02-24 18:21:28 -0500 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-02-25 13:18:29 +0100 |
| commit | 003602ad5516e59940de42e44c8d8033387bb363 (patch) | |
| tree | 43d5e8f4c77ac86e5d2e881a979c95ebb0eae3d4 /drivers/firmware | |
| parent | 0eea39a234dc52063d14541fabcb2c64516a2328 (diff) | |
| download | linux-003602ad5516e59940de42e44c8d8033387bb363.tar.gz linux-003602ad5516e59940de42e44c8d8033387bb363.tar.bz2 linux-003602ad5516e59940de42e44c8d8033387bb363.zip | |
x86/*/Makefile: Use -fno-asynchronous-unwind-tables to suppress .eh_frame sections
While discussing a patch to discard .eh_frame from the compressed
vmlinux using the linker script, Fangrui Song pointed out [1] that these
sections shouldn't exist in the first place because arch/x86/Makefile
uses -fno-asynchronous-unwind-tables.
It turns out this is because the Makefiles used to build the compressed
kernel redefine KBUILD_CFLAGS, dropping this flag.
Add the flag to the Makefile for the compressed kernel, as well as the
EFI stub Makefile to fix this.
Also add the flag to boot/Makefile and realmode/rm/Makefile so that the
kernel's boot code (boot/setup.elf) and realmode trampoline
(realmode/rm/realmode.elf) won't be compiled with .eh_frame sections,
since their linker scripts also just discard them.
[1] https://lore.kernel.org/lkml/20200222185806.ywnqhfqmy67akfsa@google.com/
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lkml.kernel.org/r/20200224232129.597160-2-nivedita@alum.mit.edu
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 98a81576213d..a1140c4ee478 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -12,7 +12,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \ -mno-mmx -mno-sse -fshort-wchar \ -Wno-pointer-sign \ $(call cc-disable-warning, address-of-packed-member) \ - $(call cc-disable-warning, gnu) + $(call cc-disable-warning, gnu) \ + -fno-asynchronous-unwind-tables # arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly # disable the stackleak plugin |