[PATCH 3.17 019/122] sparc64: Fix constraints on swab helpers.

From: Greg Kroah-Hartman
Date: Fri Dec 05 2014 - 18:54:33 EST


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

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

[ Upstream commit 5a2b59d3993e8ca4f7788a48a23e5cb303f26954 ]

We are reading the memory location, so we have to have a memory
constraint in there purely for the sake of showing the data flow
to the compiler.

Reported-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/sparc/include/uapi/asm/swab.h | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/arch/sparc/include/uapi/asm/swab.h
+++ b/arch/sparc/include/uapi/asm/swab.h
@@ -9,9 +9,9 @@ static inline __u16 __arch_swab16p(const
{
__u16 ret;

- __asm__ __volatile__ ("lduha [%1] %2, %0"
+ __asm__ __volatile__ ("lduha [%2] %3, %0"
: "=r" (ret)
- : "r" (addr), "i" (ASI_PL));
+ : "m" (*addr), "r" (addr), "i" (ASI_PL));
return ret;
}
#define __arch_swab16p __arch_swab16p
@@ -20,9 +20,9 @@ static inline __u32 __arch_swab32p(const
{
__u32 ret;

- __asm__ __volatile__ ("lduwa [%1] %2, %0"
+ __asm__ __volatile__ ("lduwa [%2] %3, %0"
: "=r" (ret)
- : "r" (addr), "i" (ASI_PL));
+ : "m" (*addr), "r" (addr), "i" (ASI_PL));
return ret;
}
#define __arch_swab32p __arch_swab32p
@@ -31,9 +31,9 @@ static inline __u64 __arch_swab64p(const
{
__u64 ret;

- __asm__ __volatile__ ("ldxa [%1] %2, %0"
+ __asm__ __volatile__ ("ldxa [%2] %3, %0"
: "=r" (ret)
- : "r" (addr), "i" (ASI_PL));
+ : "m" (*addr), "r" (addr), "i" (ASI_PL));
return ret;
}
#define __arch_swab64p __arch_swab64p


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/