[PATCH 4.9 44/59] arm64: jump_label.h: use asm_volatile_goto macro instead of "asm goto"

Greg Kroah-Hartman
2018-10-08T18:40:53Z

From: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>

[ Upstream commit 13aceef06adfaf93d52e01e28a8bc8a0ad471d83 ]

All other uses of "asm goto" go through asm_volatile_goto, which avoids
a miscompile when using GCC < 4.8.2. Replace our open-coded "asm goto"
statements with the asm_volatile_goto macro to avoid issues with older
toolchains.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/include/asm/jump_label.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/arm64/include/asm/jump_label.h
+++ b/arch/arm64/include/asm/jump_label.h
@@ -28,7 +28,7 @@

static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
{
- asm goto("1: nop\n\t"
+ asm_volatile_goto("1: nop\n\t"
".pushsection __jump_table, \"aw\"\n\t"
".align 3\n\t"
".quad 1b, %l[l_yes], %c0\n\t"
@@ -42,7 +42,7 @@ l_yes:

static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
{
- asm goto("1: b %l[l_yes]\n\t"
+ asm_volatile_goto("1: b %l[l_yes]\n\t"
".pushsection __jump_table, \"aw\"\n\t"
".align 3\n\t"
".quad 1b, %l[l_yes], %c0\n\t"