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>
diff --git a/arch/s390/kernel/perf_regs.c b/arch/s390/kernel/perf_regs.c
index 54e2d63..4352a50 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))