[PATCH 4.14 304/496] x86/alternatives: Fixup alternative_call_2

From: Greg Kroah-Hartman
Date: Mon May 28 2018 - 08:55:59 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexey Dobriyan <adobriyan@xxxxxxxxx>

[ Upstream commit bd6271039ee6f0c9b468148fc2d73e0584af6b4f ]

The following pattern fails to compile while the same pattern
with alternative_call() does:

if (...)
alternative_call_2(...);
else
alternative_call_2(...);

as it expands into

if (...)
{
}; <===
else
{
};

Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lkml.kernel.org/r/20180114120504.GA11368@avx2
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/alternative.h | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -218,13 +218,11 @@ static inline int alternatives_text_rese
*/
#define alternative_call_2(oldfunc, newfunc1, feature1, newfunc2, feature2, \
output, input...) \
-{ \
asm volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
"call %P[new2]", feature2) \
: output, ASM_CALL_CONSTRAINT \
: [old] "i" (oldfunc), [new1] "i" (newfunc1), \
- [new2] "i" (newfunc2), ## input); \
-}
+ [new2] "i" (newfunc2), ## input)

/*
* use this macro(s) if you need more than one output parameter