perf_counter/powerpc: Check oprofile_cpu_type for NULL before using it
If the current CPU doesn't support performance counters,
cur_cpu_spec->oprofile_cpu_type can be NULL. The current
perf_counter modules don't test for that case and would thus
crash at boot time.
Bug reported by David Woodhouse.
Reported-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul Mackerras <paulus@samba.org>
LKML-Reference: <19066.48028.446975.501454@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/powerpc/kernel/power4-pmu.c b/arch/powerpc/kernel/power4-pmu.c
index db90b0c..3c90a3d 100644
--- a/arch/powerpc/kernel/power4-pmu.c
+++ b/arch/powerpc/kernel/power4-pmu.c
@@ -606,7 +606,8 @@
static int init_power4_pmu(void)
{
- if (strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power4"))
+ if (!cur_cpu_spec->oprofile_cpu_type ||
+ strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power4"))
return -ENODEV;
return register_power_pmu(&power4_pmu);
