> On 25. Sep 2019, at 06:23, Joerg Roedel <[email protected]> wrote:
>
> From: Joerg Roedel <[email protected]>
>
> The traversing of this list requires protection_domain->lock to be taken
> to avoid nasty races with attach/detach code. Make sure the lock is held
> on all code-paths traversing this list.
>
> Reported-by: Filippo Sironi <[email protected]>
> Fixes: 92d420ec028d ("iommu/amd: Relax locking in dma_ops path")
> Signed-off-by: Joerg Roedel <[email protected]>
> ---
> drivers/iommu/amd_iommu.c | 25 ++++++++++++++++++++++++-
> 1 file changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index bac4e20a5919..9c26976a0f99 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -1334,8 +1334,12 @@ static void domain_flush_np_cache(struct
> protection_domain *domain,
> dma_addr_t iova, size_t size)
> {
> if (unlikely(amd_iommu_np_cache)) {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&domain->lock, flags);
> domain_flush_pages(domain, iova, size);
> domain_flush_complete(domain);
> + spin_unlock_irqrestore(&domain->lock, flags);
> }
> }
>
> @@ -1700,8 +1704,13 @@ static int iommu_map_page(struct protection_domain
> *dom,
> ret = 0;
>
> out:
> - if (updated)
> + if (updated) {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&dom->lock, flags);
> update_domain(dom);
> + spin_unlock_irqrestore(&dom->lock, flags);
> + }
>
> /* Everything flushed out, free pages now */
> free_page_list(freelist);
> @@ -1857,8 +1866,12 @@ static void free_gcr3_table(struct protection_domain
> *domain)
>
> static void dma_ops_domain_flush_tlb(struct dma_ops_domain *dom)
> {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&dom->domain.lock, flags);
> domain_flush_tlb(&dom->domain);
> domain_flush_complete(&dom->domain);
> + spin_unlock_irqrestore(&dom->domain.lock, flags);
> }
>
> static void iova_domain_flush_tlb(struct iova_domain *iovad)
> @@ -2414,6 +2427,7 @@ static dma_addr_t __map_single(struct device *dev,
> {
> dma_addr_t offset = paddr & ~PAGE_MASK;
> dma_addr_t address, start, ret;
> + unsigned long flags;
> unsigned int pages;
> int prot = 0;
> int i;
> @@ -2451,8 +2465,10 @@ static dma_addr_t __map_single(struct device *dev,
> iommu_unmap_page(&dma_dom->domain, start, PAGE_SIZE);
> }
>
> + spin_lock_irqsave(&dma_dom->domain.lock, flags);
> domain_flush_tlb(&dma_dom->domain);
> domain_flush_complete(&dma_dom->domain);
> + spin_unlock_irqrestore(&dma_dom->domain.lock, flags);
>
> dma_ops_free_iova(dma_dom, address, pages);
>
> @@ -2481,8 +2497,12 @@ static void __unmap_single(struct dma_ops_domain
> *dma_dom,
> }
>
> if (amd_iommu_unmap_flush) {
> + unsigned long flags;
> +
> + spin_lock_irqsave(&dma_dom->domain.lock, flags);
> domain_flush_tlb(&dma_dom->domain);
> domain_flush_complete(&dma_dom->domain);
> + spin_unlock_irqrestore(&dma_dom->domain.lock, flags);
> dma_ops_free_iova(dma_dom, dma_addr, pages);
> } else {
> pages = __roundup_pow_of_two(pages);
> @@ -3246,9 +3266,12 @@ static bool amd_iommu_is_attach_deferred(struct
> iommu_domain *domain,
> static void amd_iommu_flush_iotlb_all(struct iommu_domain *domain)
> {
> struct protection_domain *dom = to_pdomain(domain);
> + unsigned long flags;
>
> + spin_lock_irqsave(&dom->lock, flags);
> domain_flush_tlb_pde(dom);
> domain_flush_complete(dom);
> + spin_unlock_irqrestore(&dom->lock, flags);
> }
>
> static void amd_iommu_iotlb_sync(struct iommu_domain *domain,
> --
> 2.17.1
>
Reviewed-by: Filippo Sironi <[email protected]>
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Ralf Herbrich
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
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