From ad82a928eb58471adb2dec2001f5fbe57e5ee4b5 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik <gor@linux.ibm.com> Date: Mon, 18 Jun 2018 17:51:29 +0200 Subject: [PATCH] s390/perf: fix gcc 8 array-bounds warning arch/s390/kernel/perf_regs.c:36:19: warning: array subscript 16 is above array bounds of 'long unsigned int[16]' [-Warray-bounds] return regs->gprs[idx]; gcc tries to be smart here and since there is a condition: if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15) return regs->gprs[idx]; which covers all possible array subscripts, it gives the warning for the last function return statement: return regs->gprs[idx]; which in presence of that condition does not really make sense and should be replaced with "return 0;" Also move WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX) to the end of the function. Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> --- arch/s390/kernel/perf_regs.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/s390/kernel/perf_regs.c b/arch/s390/kernel/perf_regs.c index 54e2d634b849..4352a504f235 100644 --- a/arch/s390/kernel/perf_regs.c +++ b/arch/s390/kernel/perf_regs.c @@ -12,9 +12,6 @@ u64 perf_reg_value(struct pt_regs *regs, int idx) { freg_t fp; - if (WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX)) - return 0; - if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15) return regs->gprs[idx]; @@ -33,7 +30,8 @@ u64 perf_reg_value(struct pt_regs *regs, int idx) if (idx == PERF_REG_S390_PC) return regs->psw.addr; - return regs->gprs[idx]; + WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX); + return 0; } #define REG_RESERVED (~((1UL << PERF_REG_S390_MAX) - 1)) -- 2.30.9