From db26217e6f54647b137a0fe1f2ab346de67d6f3e Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 29 May 2015 14:44:06 +0100 Subject: [PATCH] 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 Acked-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm64/include/asm/atomic_ll_sc.h | 2 +- arch/arm64/include/asm/atomic_lse.h | 2 +- 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" -- 2.11.0