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Subject[PATCH 2/6] x86/perf/intel/cqm: Fix cqm memory leak and notifier leak
Date
Fixes the hotcpu notifier leak and other global variable memory leaks
during cqm(cache quality of service monitoring) initialization.

Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
---
arch/x86/kernel/cpu/perf_event_intel_cqm.c | 43 ++++++++++++++++++++++--------
1 file changed, 32 insertions(+), 11 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..fc704ed 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_cqm.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_cqm.c
@@ -211,6 +211,20 @@ static void __put_rmid(u32 rmid)
list_add_tail(&entry->list, &cqm_rmid_limbo_lru);
}

+static void cqm_cleanup(void)
+{
+ int i;
+
+ if (!cqm_rmid_ptrs)
+ return;
+
+ for (i = 0; i < cqm_max_rmid; i++)
+ kfree(cqm_rmid_ptrs[i]);
+
+ kfree(cqm_rmid_ptrs);
+ cqm_rmid_ptrs = NULL;
+}
+
static int intel_cqm_setup_rmid_cache(void)
{
struct cqm_rmid_entry *entry;
@@ -218,7 +232,7 @@ static int intel_cqm_setup_rmid_cache(void)
int r = 0;

nr_rmids = cqm_max_rmid + 1;
- cqm_rmid_ptrs = kmalloc(sizeof(struct cqm_rmid_entry *) *
+ cqm_rmid_ptrs = kzalloc(sizeof(struct cqm_rmid_entry *) *
nr_rmids, GFP_KERNEL);
if (!cqm_rmid_ptrs)
return -ENOMEM;
@@ -249,11 +263,9 @@ static int intel_cqm_setup_rmid_cache(void)
mutex_unlock(&cache_mutex);

return 0;
-fail:
- while (r--)
- kfree(cqm_rmid_ptrs[r]);

- kfree(cqm_rmid_ptrs);
+fail:
+ cqm_cleanup();
return -ENOMEM;
}

@@ -1322,7 +1334,7 @@ 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 +1394,25 @@ 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
- pr_info("Intel CQM monitoring enabled\n");
+ goto out;
+ }
+
+ 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);
+ cqm_cleanup();
+ }

return ret;
}
--
1.9.1
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