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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 /arch/x86 | |
| parent | 0eea39a234dc52063d14541fabcb2c64516a2328 (diff) | |
| download | linux-003602ad5516e59940de42e44c8d8033387bb363.tar.gz | |
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 'arch/x86')
| -rw-r--r-- | arch/x86/boot/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/realmode/rm/Makefile | 1 |
3 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile index 012b82fc8617..24f011e0adf1 100644 --- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -68,6 +68,7 @@ clean-files += cpustr.h KBUILD_CFLAGS := $(REALMODE_CFLAGS) -D_SETUP KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables GCOV_PROFILE := n UBSAN_SANITIZE := n diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 26050ae0b27e..c33111341325 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -39,6 +39,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) KBUILD_CFLAGS += $(call cc-disable-warning, gnu) KBUILD_CFLAGS += -Wno-pointer-sign KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ GCOV_PROFILE := n diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile index 99b6332ba540..b11ec5d8f8ac 100644 --- a/arch/x86/realmode/rm/Makefile +++ b/arch/x86/realmode/rm/Makefile @@ -71,5 +71,6 @@ $(obj)/realmode.relocs: $(obj)/realmode.elf FORCE KBUILD_CFLAGS := $(REALMODE_CFLAGS) -D_SETUP -D_WAKEUP \ -I$(srctree)/arch/x86/boot KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables GCOV_PROFILE := n UBSAN_SANITIZE := n |