From 2b42717b28ddd8f249be5daa37d974ccbc275b40 Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolvanen@google.com>
Date: Thu, 4 Apr 2019 14:59:57 -0700
Subject: [PATCH] UPSTREAM: x86/build: Keep local relocations with ld.lld

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.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: clang-built-linux@googlegroups.com
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190404214027.GA7324@beast
Link: https://github.com/ClangBuiltLinux/linux/issues/404
Change-Id: If16af606aee95770bee98fc662867115b3a8572a
(cherry picked from commit 7c21383f3429dd70da39c0c7f1efa12377a47ab6)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 arch/x86/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 7aae8cde1dea..ff18580c0445 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
 
 #