[PATCH 4.4 101/192] [PATCH 105/135] perf/x86/cqm: Fix CQM memory leak and notifier leak

From: Greg Kroah-Hartman
Date: Mon Sep 12 2016 - 13:10:31 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit ada2f634cd50d050269b67b4e2966582387e7c27 ]

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@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: fenghua.yu@xxxxxxxxx
Cc: h.peter.anvin@xxxxxxxxx
Cc: ravi.v.shankar@xxxxxxxxx
Cc: vikas.shivappa@xxxxxxxxx
Link: http://lkml.kernel.org/r/1457652732-4499-3-git-send-email-vikas.shivappa@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel_cqm.c | 43 +++++++++++++++++++++--------
1 file changed, 32 insertions(+), 11 deletions(-)

--- 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(vo
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(vo
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

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;
}