2019-10-06 13:16:16

by Thomas Bogendoerfer

Subject: [PATCH] MIPS: include: Mark __cmpxchd as __always_inline

Commit ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING
forcibly") allows compiler to uninline functions marked as 'inline'.
In cace of cmpxchg this would cause to reference function
__cmpxchg_called_with_bad_pointer, which is a error case
for catching bugs and will not happen for correct code, if
__cmpxchg is inlined.

Signed-off-by: Thomas Bogendoerfer <[email protected]>
---
arch/mips/include/asm/cmpxchg.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h
index 79bf34efbc04..012dcf7046ad 100644
--- a/arch/mips/include/asm/cmpxchg.h
+++ b/arch/mips/include/asm/cmpxchg.h
@@ -153,8 +153,9 @@ static inline unsigned long __xchg(volatile void *ptr, unsigned long x,
extern unsigned long __cmpxchg_small(volatile void *ptr, unsigned long old,
unsigned long new, unsigned int size);

-static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
- unsigned long new, unsigned int size)
+static __always_inline
+unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+ unsigned long new, unsigned int size)
{
switch (size) {
case 1:
--
2.16.4

2019-10-07 17:51:03

by Paul Burton

Subject: Re: [PATCH] MIPS: include: Mark __cmpxchd as __always_inline

Hello,

Thomas Bogendoerfer wrote:
> Commit ac7c3e4ff401 ("compiler: enable CONFIG_OPTIMIZE_INLINING
> forcibly") allows compiler to uninline functions marked as 'inline'.
> In cace of cmpxchg this would cause to reference function
> __cmpxchg_called_with_bad_pointer, which is a error case
> for catching bugs and will not happen for correct code, if
> __cmpxchg is inlined.

Applied to mips-fixes.

> commit 88356d09904b
> https://git.kernel.org/mips/c/88356d09904b
>
> Signed-off-by: Thomas Bogendoerfer <[email protected]>
> [[email protected]: s/__cmpxchd/__cmpxchg in subject]
> Signed-off-by: Paul Burton <[email protected]>

Thanks,
Paul

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