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authorMichael Clark <[email protected]>2019-02-11 17:38:29 +1300
committerPaul Burton <[email protected]>2019-02-11 12:02:08 -0800
commit94ee12b507db8b5876e31c9d6c9d84f556a4b49f (patch)
tree66e5bc74fdb473319506f7ea63319d85fb3608a2
parentd13937116f1e82bf508a6325111b322c30c85eb9 (diff)
MIPS: fix truncation in __cmpxchg_small for short values
__cmpxchg_small erroneously uses u8 for load comparison which can be either char or short. This patch changes the local variable to u32 which is sufficiently sized, as the loaded value is already masked and shifted appropriately. Using an integer size avoids any unnecessary canonicalization from use of non native widths. This patch is part of a series that adapts the MIPS small word atomics code for xchg and cmpxchg on short and char to RISC-V. Cc: RISC-V Patches <[email protected]> Cc: Linux RISC-V <[email protected]> Cc: Linux MIPS <[email protected]> Signed-off-by: Michael Clark <[email protected]> [[email protected]: - Fix varialble typo per Jonas Gorski. - Consolidate load variable with other declarations.] Signed-off-by: Paul Burton <[email protected]> Fixes: 3ba7f44d2b19 ("MIPS: cmpxchg: Implement 1 byte & 2 byte cmpxchg()") Cc: [email protected] # v4.13+
-rw-r--r--arch/mips/kernel/cmpxchg.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/mips/kernel/cmpxchg.c b/arch/mips/kernel/cmpxchg.c
index 0b9535bc2c53..6b2a4a902a98 100644
--- a/arch/mips/kernel/cmpxchg.c
+++ b/arch/mips/kernel/cmpxchg.c
@@ -54,10 +54,9 @@ unsigned long __xchg_small(volatile void *ptr, unsigned long val, unsigned int s
unsigned long __cmpxchg_small(volatile void *ptr, unsigned long old,
unsigned long new, unsigned int size)
{
- u32 mask, old32, new32, load32;
+ u32 mask, old32, new32, load32, load;
volatile u32 *ptr32;
unsigned int shift;
- u8 load;
/* Check that ptr is naturally aligned */
WARN_ON((unsigned long)ptr & (size - 1));