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* [PATCH] x86/build: Keep local relocations with ld.lld
@ 2019-04-04 21:40 Kees Cook
  2019-04-05 10:40 ` [tip:x86/build] " tip-bot for Kees Cook
  0 siblings, 1 reply; 2+ messages in thread
From: Kees Cook @ 2019-04-04 21:40 UTC (permalink / raw)
  To: Thomas Gleixner; +Cc: x86, Nick Desaulniers, linux-kernel, clang-built-linux

The LLVM linker (ld.lld) defaults to removing local relocations, which
causes KASLR boot failures. ld.bfd and ld.gold already handle this
correctly. This adds the explicit instruction "--discard-none" during
the link phase. There is no change in output for ld.bfd and ld.gold,
but ld.lld now produces an image with all the needed relocations.

Link: https://github.com/ClangBuiltLinux/linux/issues/404
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index a587805c6687..56e748a7679f 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -47,7 +47,7 @@ export REALMODE_CFLAGS
 export BITS
 
 ifdef CONFIG_X86_NEED_RELOCS
-        LDFLAGS_vmlinux := --emit-relocs
+        LDFLAGS_vmlinux := --emit-relocs --discard-none
 endif
 
 #
-- 
2.17.1


-- 
Kees Cook

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2019-04-04 21:40 [PATCH] x86/build: Keep local relocations with ld.lld Kees Cook
2019-04-05 10:40 ` [tip:x86/build] " tip-bot for Kees Cook

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