perf/x86/cqm: Fix CQM memory leak and notifier leak

Fixes the hotcpu notifier leak and other global variable memory leaks
during CQM (cache quality of service monitoring) initialization.

Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: fenghua.yu@intel.com
Cc: h.peter.anvin@intel.com
Cc: ravi.v.shankar@intel.com
Cc: vikas.shivappa@intel.com
Link: http://lkml.kernel.org/r/1457652732-4499-3-git-send-email-vikas.shivappa@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/events/intel/cqm.c b/arch/x86/events/intel/cqm.c
index b0226f1912a21ed92d70bf6b438150cce16e80c2..dbb058d2910a0dd9d7ac51ad03d81783116d6752 100644 (file)
--- a/arch/x86/events/intel/cqm.c
+++ b/arch/x86/events/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;
 }
 
@@ -1312,7 +1324,7 @@ 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))
@@ -1372,16 +1384,25 @@ 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;
 }