Messages in this thread | | | Date | Wed, 22 Jun 2022 14:46:19 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH] iommu/dma: Fix race condition during iova_domain initialization |
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Please re-send with
Robin Murphy <robin.murphy@arm.com>
in Cc.
On Mon, May 30, 2022 at 08:07:45PM +0800, yf.wang@mediatek.com wrote: > From: Yunfei Wang <yf.wang@mediatek.com> > > When many devices share the same iova domain, iommu_dma_init_domain() > may be called at the same time. The checking of iovad->start_pfn will > all get false in iommu_dma_init_domain() and both enter init_iova_domain() > to do iovad initialization. > > Fix this by protecting init_iova_domain() with iommu_dma_cookie->mutex. > > Exception backtrace: > rb_insert_color(param1=0xFFFFFF80CD2BDB40, param3=1) + 64 > init_iova_domain() + 180 > iommu_setup_dma_ops() + 260 > arch_setup_dma_ops() + 132 > of_dma_configure_id() + 468 > platform_dma_configure() + 32 > really_probe() + 1168 > driver_probe_device() + 268 > __device_attach_driver() + 524 > __device_attach() + 524 > bus_probe_device() + 64 > deferred_probe_work_func() + 260 > process_one_work() + 580 > worker_thread() + 1076 > kthread() + 332 > ret_from_fork() + 16 > > Signed-off-by: Ning Li <ning.li@mediatek.com> > Signed-off-by: Yunfei Wang <yf.wang@mediatek.com> > --- > drivers/iommu/dma-iommu.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index 09f6e1c0f9c0..b38c5041eeab 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -63,6 +63,7 @@ struct iommu_dma_cookie { > > /* Domain for flush queue callback; NULL if flush queue not in use */ > struct iommu_domain *fq_domain; > + struct mutex mutex; > }; > > static DEFINE_STATIC_KEY_FALSE(iommu_deferred_attach_enabled); > @@ -309,6 +310,7 @@ int iommu_get_dma_cookie(struct iommu_domain *domain) > if (!domain->iova_cookie) > return -ENOMEM; > > + mutex_init(&domain->iova_cookie->mutex); > return 0; > } > > @@ -549,26 +551,33 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, > } > > /* start_pfn is always nonzero for an already-initialised domain */ > + mutex_lock(&cookie->mutex); > if (iovad->start_pfn) { > if (1UL << order != iovad->granule || > base_pfn != iovad->start_pfn) { > pr_warn("Incompatible range for DMA domain\n"); > - return -EFAULT; > + ret = -EFAULT; > + goto done_unlock; > } > > - return 0; > + ret = 0; > + goto done_unlock; > } > > init_iova_domain(iovad, 1UL << order, base_pfn); > ret = iova_domain_init_rcaches(iovad); > if (ret) > - return ret; > + goto done_unlock; > > /* If the FQ fails we can simply fall back to strict mode */ > if (domain->type == IOMMU_DOMAIN_DMA_FQ && iommu_dma_init_fq(domain)) > domain->type = IOMMU_DOMAIN_DMA; > > - return iova_reserve_iommu_regions(dev, domain); > + ret = iova_reserve_iommu_regions(dev, domain); > + > +done_unlock: > + mutex_unlock(&cookie->mutex); > + return ret; > } > > /** > -- > 2.18.0
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