Messages in this thread | | | Subject | Re: [PATCH -next] iommu/dma: Fix missing mutex_init() in iommu_get_msi_cookie() | From | Yang Yingliang <> | Date | Mon, 18 Jul 2022 14:42:39 +0800 |
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Hi,
On 2022/7/15 17:28, Robin Murphy wrote: > On 2022-07-15 08:49, Joerg Roedel wrote: >> Adding Robin. >> >> On Mon, Jun 27, 2022 at 04:55:33PM +0800, Yang Yingliang wrote: >>> cookie_alloc() is called by iommu_get_dma_cookie() and >>> iommu_get_msi_cookie(), >>> but the mutex is only initialized in iommu_get_dma_cookie(), move >>> mutex_init() >>> into cookie_alloc() to make sure the mutex will be initialized. > > The mutex is only used in iommu_dma_init_domain(), which is only > called by iommu_setup_dma_ops() for IOMMU_DOMAIN_DMA domains. How is > there a problem here? It's no problem now, but I thinks it's better to initialize the 'mutex' in cookie_alloc() to make code stronger.
Thanks, Yang > > Robin. > >>> Fixes: ac9a5d522bb8 ("iommu/dma: Fix race condition during >>> iova_domain initialization") >>> Reported-by: Hulk Robot <hulkci@huawei.com> >>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> >>> --- >>> drivers/iommu/dma-iommu.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c >>> index 1910f4f1612b..e29157380c48 100644 >>> --- a/drivers/iommu/dma-iommu.c >>> +++ b/drivers/iommu/dma-iommu.c >>> @@ -294,6 +294,7 @@ static struct iommu_dma_cookie >>> *cookie_alloc(enum iommu_dma_cookie_type type) >>> if (cookie) { >>> INIT_LIST_HEAD(&cookie->msi_page_list); >>> cookie->type = type; >>> + mutex_init(&cookie->mutex); >>> } >>> return cookie; >>> } >>> @@ -311,7 +312,6 @@ int iommu_get_dma_cookie(struct iommu_domain >>> *domain) >>> if (!domain->iova_cookie) >>> return -ENOMEM; >>> - mutex_init(&domain->iova_cookie->mutex); >>> return 0; >>> } >>> -- >>> 2.25.1 > .
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