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

[Vikas Shivappa]

On Wed, 2 Mar 2016, Thomas Gleixner wrote:

On Tue, 1 Mar 2016, Vikas Shivappa wrote:

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

Reviewed-by: Tony Luck <tony.l...@intel.com>
Signed-off-by: Vikas Shivappa <vikas.shiva...@linux.intel.com>
---
 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);

This still leaks cqm_rmid_ptrs ....


Thats right. Thought there must be something more than the str leak i fixed, 
but missed this. Will fix

Thanks,
Vikas