perf/x86/intel: Plug memory leak in intel_pmu_init()

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@nokia.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 09c26a4..731153a 100644 (file)
--- 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;
 }