Re: [PATCH] drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling
From: Robin Murphy <robin.murphy@arm.com>
Date: 2020-07-16 10:26:30
Also in:
lkml
On 2020-07-16 10:41, Will Deacon wrote:
On Thu, Jul 16, 2020 at 05:19:25PM +0800, Qi Liu wrote:quoted
Kernel panic will also happen when users try to unbind PMU drivers with device. This unbind issue could be solved by another patch latter. drivers/perf/arm_smmuv3_pmu.c | 1 + drivers/perf/fsl_imx8_ddr_perf.c | 1 + drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c | 1 + drivers/perf/hisilicon/hisi_uncore_hha_pmu.c | 1 + drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c | 1 + 5 files changed, 5 insertions(+)diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c index 48e28ef..90caba56 100644 --- a/drivers/perf/arm_smmuv3_pmu.c +++ b/drivers/perf/arm_smmuv3_pmu.c@@ -742,6 +742,7 @@ static int smmu_pmu_probe(struct platform_device *pdev) platform_set_drvdata(pdev, smmu_pmu); smmu_pmu->pmu = (struct pmu) { + .module = THIS_MODULE,I thought platform_driver_register() did this automatically?
For the platform device itself, yes, but this is for the PMU device - perf needs to take a reference to the module, otherwise the platform device can still be pulled out from under its feet. I can't remember if we ever discussed making perf_pmu_register() do the same trick as platform_device_register() and friends, but obviously it's a possibility. Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel