From: Kees Cook <keescook@chromium.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org, Nick Desaulniers <ndesaulniers@google.com>,
linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: [PATCH] x86/build: Keep local relocations with ld.lld
Date: Thu, 4 Apr 2019 14:40:27 -0700 [thread overview]
Message-ID: <20190404214027.GA7324@beast> (raw)
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
next reply other threads:[~2019-04-04 21:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 21:40 Kees Cook [this message]
2019-04-05 10:40 ` [tip:x86/build] x86/build: Keep local relocations with ld.lld tip-bot for Kees Cook
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