Commit 0f254c76 authored May 31, 2016 by Julien Grall Committed by Will Deacon Jun 03, 2016

drivers/perf: arm_pmu: Defer the setting of __oprofile_cpu_pmu



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).

Cc: <stable@vger.kernel.org>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

parent 121323ae

drivers/perf/arm_pmu.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -992,9 +992,6 @@ 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))) {
		@@ -1030,6 +1027,9 @@ 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);

Admin message