[PATCH AUTOSEL for 4.14 064/110] perf/x86/intel: Plug memory leak in intel_pmu_init()

[Sasha Levin]

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

[ Upstream commit 7ad1437d6ace0e450a6c1167720608ad660b191d ]

A recent commit introduced an extra merge_attr() call in the skylake
branch, which causes a memory leak.

Store the pointer to the extra allocated memory and free it at the end of
the function.

Fixes: a5df70c354c2 ("perf/x86: Only show format attributes when supported")
Reported-by: Tommi Rantala <tommi.t.rantala@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 arch/x86/events/intel/core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 09c26a4f139c..731153a4681e 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3847,6 +3847,8 @@ static struct attribute *intel_pmu_attrs[] = {
 
 __init int intel_pmu_init(void)
 {
+	struct attribute **extra_attr = NULL;
+	struct attribute **to_free = NULL;
 	union cpuid10_edx edx;
 	union cpuid10_eax eax;
 	union cpuid10_ebx ebx;
@@ -3854,7 +3856,6 @@ __init int intel_pmu_init(void)
 	unsigned int unused;
 	struct extra_reg *er;
 	int version, i;
-	struct attribute **extra_attr = NULL;
 	char *name;
 
 	if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
@@ -4294,6 +4295,7 @@ __init int intel_pmu_init(void)
 		extra_attr = boot_cpu_has(X86_FEATURE_RTM) ?
 			hsw_format_attr : nhm_format_attr;
 		extra_attr = merge_attr(extra_attr, skl_format_attr);
+		to_free = extra_attr;
 		x86_pmu.cpu_events = get_hsw_events_attrs();
 		intel_pmu_pebs_data_source_skl(
 			boot_cpu_data.x86_model == INTEL_FAM6_SKYLAKE_X);
@@ -4401,6 +4403,7 @@ __init int intel_pmu_init(void)
 		pr_cont("full-width counters, ");
 	}
 
+	kfree(to_free);
 	return 0;
 }
 
-- 
2.11.0