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authorWill Deacon <will.deacon@arm.com>2015-05-29 14:44:06 +0100
committerWill Deacon <will.deacon@arm.com>2015-07-27 15:28:54 +0100
commitdb26217e6f54647b137a0fe1f2ab346de67d6f3e (patch)
tree5c839d3429de197f511161be339bcdacb786d471 /arch/arm64/include
parent6059a7b6e818023436a9058170a4fea1c670dc98 (diff)
arm64: atomic64_dec_if_positive: fix incorrect branch condition
If we attempt to atomic64_dec_if_positive on INT_MIN, we will underflow and incorrectly decide that the original parameter was positive. This patches fixes the broken condition code so that we handle this corner case correctly. Reviewed-by: Steve Capper <steve.capper@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include')
-rw-r--r--arch/arm64/include/asm/atomic_ll_sc.h2
-rw-r--r--arch/arm64/include/asm/atomic_lse.h2
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h
index 5e2d1db3a1db..6671978e60fe 100644
--- a/arch/arm64/include/asm/atomic_ll_sc.h
+++ b/arch/arm64/include/asm/atomic_ll_sc.h
@@ -159,7 +159,7 @@ __LL_SC_PREFIX(atomic64_dec_if_positive(atomic64_t *v))
" prfm pstl1strm, %2\n"
"1: ldxr %0, %2\n"
" subs %0, %0, #1\n"
-" b.mi 2f\n"
+" b.lt 2f\n"
" stlxr %w1, %0, %2\n"
" cbnz %w1, 1b\n"
" dmb ish\n"
diff --git a/arch/arm64/include/asm/atomic_lse.h b/arch/arm64/include/asm/atomic_lse.h
index 30e5cbcfc707..f873bf61e17b 100644
--- a/arch/arm64/include/asm/atomic_lse.h
+++ b/arch/arm64/include/asm/atomic_lse.h
@@ -291,7 +291,7 @@ static inline long atomic64_dec_if_positive(atomic64_t *v)
/* LSE atomics */
"1: ldr x30, %[v]\n"
" subs %[ret], x30, #1\n"
- " b.mi 2f\n"
+ " b.lt 2f\n"
" casal x30, %[ret], %[v]\n"
" sub x30, x30, #1\n"
" sub x30, x30, %[ret]\n"