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iommu/dma: Fix race condition during iova_domain initialization

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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>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Miles Chen <miles.chen@mediatek.com>
Link: https://lore.kernel.org/r/20220530120748.31733-1-yf.wang@mediatek.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Yunfei Wang 2022-05-30 20:07:45 +08:00 committed by Joerg Roedel
parent 4bf7fda4dc
commit ac9a5d522b
1 changed files with 13 additions and 4 deletions
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17
drivers/iommu/dma-iommu.c
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@ -64,6 +64,7 @@ struct iommu_dma_cookie {
/* Domain for flush queue callback; NULL if flush queue not in use */ /* Domain for flush queue callback; NULL if flush queue not in use */
struct iommu_domain *fq_domain; struct iommu_domain *fq_domain;
struct mutex mutex;
}; };
static DEFINE_STATIC_KEY_FALSE(iommu_deferred_attach_enabled); static DEFINE_STATIC_KEY_FALSE(iommu_deferred_attach_enabled);
@ -310,6 +311,7 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
if (!domain->iova_cookie) if (!domain->iova_cookie)
return -ENOMEM; return -ENOMEM;
mutex_init(&domain->iova_cookie->mutex);
return 0; return 0;
} }
@ -560,26 +562,33 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
} }
/* start_pfn is always nonzero for an already-initialised domain */ /* start_pfn is always nonzero for an already-initialised domain */
mutex_lock(&cookie->mutex);
if (iovad->start_pfn) { if (iovad->start_pfn) {
if (1UL << order != iovad->granule || if (1UL << order != iovad->granule ||
base_pfn != iovad->start_pfn) { base_pfn != iovad->start_pfn) {
pr_warn("Incompatible range for DMA domain\n"); 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); init_iova_domain(iovad, 1UL << order, base_pfn);
ret = iova_domain_init_rcaches(iovad); ret = iova_domain_init_rcaches(iovad);
if (ret) if (ret)
return ret; goto done_unlock;
/* If the FQ fails we can simply fall back to strict mode */ /* If the FQ fails we can simply fall back to strict mode */
if (domain->type == IOMMU_DOMAIN_DMA_FQ && iommu_dma_init_fq(domain)) if (domain->type == IOMMU_DOMAIN_DMA_FQ && iommu_dma_init_fq(domain))
domain->type = IOMMU_DOMAIN_DMA; 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;
} }
/** /**