[tip:x86/urgent] x86/vdso: Drop implicit common-page-size linker flag

From: tip-bot for Nick Desaulniers
Date: Fri Dec 07 2018 - 13:34:34 EST


Commit-ID: ac3e233d29f7f77f28243af0132057d378d3ea58
Gitweb: https://git.kernel.org/tip/ac3e233d29f7f77f28243af0132057d378d3ea58
Author: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
AuthorDate: Thu, 6 Dec 2018 11:12:31 -0800
Committer: Borislav Petkov <bp@xxxxxxx>
CommitDate: Fri, 7 Dec 2018 18:57:38 +0100

x86/vdso: Drop implicit common-page-size linker flag

GNU linker's -z common-page-size's default value is based on the target
architecture. arch/x86/entry/vdso/Makefile sets it to the architecture
default, which is implicit and redundant. Drop it.

Fixes: 2aae950b21e4 ("x86_64: Add vDSO for x86-64 with gettimeofday/clock_gettime/getcpu")
Reported-by: Dmitry Golovin <dima@xxxxxxxxxx>
Reported-by: Bill Wendling <morbo@xxxxxxxxxx>
Suggested-by: Dmitry Golovin <dima@xxxxxxxxxx>
Suggested-by: Rui Ueyama <ruiu@xxxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Fangrui Song <maskray@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86-ml <x86@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20181206191231.192355-1-ndesaulniers@xxxxxxxxxx
Link: https://bugs.llvm.org/show_bug.cgi?id=38774
Link: https://github.com/ClangBuiltLinux/linux/issues/31
---
arch/x86/entry/vdso/Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 141d415a8c80..0624bf2266fd 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -47,7 +47,7 @@ targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
CPPFLAGS_vdso.lds += -P -C

VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 --no-undefined \
- -z max-page-size=4096 -z common-page-size=4096
+ -z max-page-size=4096

$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
$(call if_changed,vdso)
@@ -98,7 +98,7 @@ CFLAGS_REMOVE_vvar.o = -pg

CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
- -z max-page-size=4096 -z common-page-size=4096
+ -z max-page-size=4096

# x32-rebranded versions
vobjx32s-y := $(vobjs-y:.o=-x32.o)