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authorYunfei Wang <yf.wang@mediatek.com>2022-05-30 14:07:45 +0200
committerJoerg Roedel <jroedel@suse.de>2022-06-22 15:41:25 +0200
commitac9a5d522bb80be50ea84965699e1c8257d745ce (patch)
tree79b8e046318a12d65539bb726e6895d7cfc599fc /drivers/iommu
parentiommu/dma: Add config for PCI SAC address trick (diff)
downloadlinux-ac9a5d522bb80be50ea84965699e1c8257d745ce.tar.xz
linux-ac9a5d522bb80be50ea84965699e1c8257d745ce.zip
iommu/dma: Fix race condition during iova_domain initialization
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>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/dma-iommu.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 9f9d9ba7f376..1910f4f1612b 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -64,6 +64,7 @@ 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);
@@ -310,6 +311,7 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
if (!domain->iova_cookie)
return -ENOMEM;
+ mutex_init(&domain->iova_cookie->mutex);
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 */
+ 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;
}
/**