Re: [PATCH v2] iommu: fix smmu initialization memory leak problem

Will Deacon
2022-11-29T15:26:11Z

On Tue, Nov 22, 2022 at 08:00:39PM +0800, liulongfang wrote:
> On 2022/11/22 2:05, Will Deacon wrote:
> > On Mon, Nov 21, 2022 at 11:04:21AM +0800, Longfang Liu wrote:
> >> When iommu_device_register() in arm_smmu_device_probe() fails,
> >> in addition to sysfs needs to be deleted, device should also
> >> be disabled, and the memory of iopf needs to be released to
> >> prevent memory leak of iopf.
> >>
> >> Changes v1 -> v2:
> >> -Improve arm_smmu_device_probe() abnormal exit function.
> >>
> >> Signed-off-by: Longfang Liu <liulongfang@huawei.com>
> >> ---
> >> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 16 +++++++++++-----
> >> 1 file changed, 11 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> >> index ab160198edd6..b892f5233f88 100644
> >> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> >> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> >> @@ -3815,7 +3815,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
> >> /* Initialise in-memory data structures */
> >> ret = arm_smmu_init_structures(smmu);
> >> if (ret)
> >> - return ret;
> >> + goto err_iopf;
> >>
> >> /* Record our private device structure */
> >> platform_set_drvdata(pdev, smmu);
> >> @@ -3826,22 +3826,28 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
> >> /* Reset the device */
> >> ret = arm_smmu_device_reset(smmu, bypass);
> >> if (ret)
> >> - return ret;
> >> + goto err_iopf;
> >>
> >> /* And we're up. Go go go! */
> >> ret = iommu_device_sysfs_add(&smmu->iommu, dev, NULL,
> >> "smmu3.%pa", &ioaddr);
> >> if (ret)
> >> - return ret;
> >> + goto err_reset;
> >>
> >> ret = iommu_device_register(&smmu->iommu, &arm_smmu_ops, dev);
> >> if (ret) {
> >> dev_err(dev, "Failed to register iommu\n");
> >> - iommu_device_sysfs_remove(&smmu->iommu);
> >> - return ret;
> >> + goto err_sysfs_add;
> >> }
> >>
> >> return 0;
> >> +err_sysfs_add:
> >> + iommu_device_sysfs_remove(&smmu->iommu);
> >> +err_reset:
> >> + arm_smmu_device_disable(smmu);
> >> +err_iopf:
> >> + iopf_queue_free(smmu->evtq.iopf);
> >> + return ret;
> >
> > I previously suggested using devres_alloc() for this instead. Did that
> > not work?
> >
>
> This patch is only for fixing iopf's memory leak.
> The use of devres_alloc() is an optimization solution for iopf queue management,
> which is another set of patch matters.

Great, I look forward to that set of patches!

Will