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authorFangrui Song <maskray@google.com>2020-05-20 11:20:10 -0700
committerBorislav Petkov <bp@suse.de>2020-05-22 12:42:07 +0200
commitd6ee6529436a15a0541aff6e1697989ee7dc2c44 (patch)
tree310a4d693963f6f5a51f6d856b78e4303c65df72
parent675a59b7dec6e03c5fb060f18fc25b2e56be3c7a (diff)
x86/boot: Discard .discard.unreachable for arch/x86/boot/compressed/vmlinux
With commit ce5e3f909fc0 ("efi/printf: Add 64-bit and 8-bit integer support") arch/x86/boot/compressed/vmlinux may have an undesired .discard.unreachable section coming from drivers/firmware/efi/libstub/vsprintf.stub.o. That section gets generated from unreachable() annotations when CONFIG_STACK_VALIDATION is enabled. .discard.unreachable contains an R_X86_64_PC32 relocation which will be warned about by LLD: a non-SHF_ALLOC section (.discard.unreachable) is not part of the memory image, thus conceptually the distance between a non-SHF_ALLOC and a SHF_ALLOC is not a constant which can be resolved at link time: % ld.lld -m elf_x86_64 -T arch/x86/boot/compressed/vmlinux.lds ... -o arch/x86/boot/compressed/vmlinux ld.lld: warning: vsprintf.c:(.discard.unreachable+0x0): has non-ABS relocation R_X86_64_PC32 against symbol '' Reuse the DISCARDS macro which includes .discard.* to drop .discard.unreachable. [ bp: Massage and complete the commit message. ] Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Arvind Sankar <nivedita@alum.mit.edu> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Link: https://lkml.kernel.org/r/20200520182010.242489-1-maskray@google.com
-rw-r--r--arch/x86/boot/compressed/vmlinux.lds.S2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S
index 508cfa6828c5..1031af142776 100644
--- a/arch/x86/boot/compressed/vmlinux.lds.S
+++ b/arch/x86/boot/compressed/vmlinux.lds.S
@@ -73,4 +73,6 @@ SECTIONS
#endif
. = ALIGN(PAGE_SIZE); /* keep ZO size page aligned */
_end = .;
+
+ DISCARDS
}