[PATCH 2/6] x86,perf/cqm: Fix cqm memory leak and notifier leak

From: Vikas Shivappa
Date: Tue Mar 01 2016 - 18:49:25 EST


Fixes the hotcpu notifier leak and a memory leak during cqm(cache
quality of service monitoring) initialization.

Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel_cqm.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_cqm.c b/arch/x86/kernel/cpu/perf_event_intel_cqm.c
index e6be335..5666171 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_cqm.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_cqm.c
@@ -1322,7 +1322,7 @@ static const struct x86_cpu_id intel_cqm_match[] = {

static int __init intel_cqm_init(void)
{
- char *str, scale[20];
+ char *str = NULL, scale[20];
int i, cpu, ret;

if (!x86_match_cpu(intel_cqm_match))
@@ -1382,16 +1382,23 @@ static int __init intel_cqm_init(void)
cqm_pick_event_reader(i);
}

- __perf_cpu_notifier(intel_cqm_cpu_notifier);
-
ret = perf_pmu_register(&intel_cqm_pmu, "intel_cqm", -1);
- if (ret)
+ if (ret) {
pr_err("Intel CQM perf registration failed: %d\n", ret);
- else
+ goto out;
+ } else {
pr_info("Intel CQM monitoring enabled\n");
+ }

+ /*
+ * Register the hot cpu notifier once we are sure cqm
+ * is enabled to avoid notifier leak.
+ */
+ __perf_cpu_notifier(intel_cqm_cpu_notifier);
out:
cpu_notifier_register_done();
+ if (ret)
+ kfree(str);

return ret;
}
--
1.9.1