From: Julien Grall Date: Tue, 31 May 2016 11:41:22 +0000 (+0100) Subject: drivers/perf: arm_pmu: Defer the setting of __oprofile_cpu_pmu X-Git-Tag: v4.6.3~58 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=711d9f5dd7ff4e386b865bb8f6357f805a55f92c;p=thirdparty%2Fkernel%2Fstable.git drivers/perf: arm_pmu: Defer the setting of __oprofile_cpu_pmu commit 0f254c7671e851243412bce6c2e618732831d0f8 upstream. The global variable __oprofile_cpu_pmu is set before the PMU is fully initialized. If an error occurs before the end of the initialization, the PMU will be freed and the variable will contain an invalid pointer. This will result in a kernel crash when perf will be used. Fix it by moving the setting of __oprofile_cpu_pmu when the PMU is fully initialized (i.e when it is no longer possible to fail). Signed-off-by: Julien Grall Acked-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index f70090897fdf1..0e537fdc1d086 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -987,9 +987,6 @@ int arm_pmu_device_probe(struct platform_device *pdev, armpmu_init(pmu); - if (!__oprofile_cpu_pmu) - __oprofile_cpu_pmu = pmu; - pmu->plat_device = pdev; if (node && (of_id = of_match_node(of_table, pdev->dev.of_node))) { @@ -1025,6 +1022,9 @@ int arm_pmu_device_probe(struct platform_device *pdev, if (ret) goto out_destroy; + if (!__oprofile_cpu_pmu) + __oprofile_cpu_pmu = pmu; + pr_info("enabled with %s PMU driver, %d counters available\n", pmu->name, pmu->num_events);