From 9db034d57a8b3cd0aa135a725849cd55a3b2f991 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 9 Nov 2018 12:07:10 +0100 Subject: [PATCH] iommu/amd: Restart loop if cmpxchg64 succeeded in alloc_pte() This makes sure that __pte always contains the correct value when the pointer to the next page-table level is derived. Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 6a88ba9..c539b2a 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1474,13 +1474,12 @@ static u64 *alloc_pte(struct protection_domain *domain, __npte = PM_LEVEL_PDE(level, iommu_virt_to_phys(page)); /* pte could have been changed somewhere. */ - if (cmpxchg64(pte, __pte, __npte) != __pte) { + if (cmpxchg64(pte, __pte, __npte) != __pte) free_page((unsigned long)page); - continue; - } - - if (pte_level == PAGE_MODE_7_LEVEL) + else if (pte_level == PAGE_MODE_7_LEVEL) domain->updated = true; + + continue; } /* No level skipping support yet */ @@ -1489,7 +1488,7 @@ static u64 *alloc_pte(struct protection_domain *domain, level -= 1; - pte = IOMMU_PTE_PAGE(*pte); + pte = IOMMU_PTE_PAGE(__pte); if (pte_page && level == end_lvl) *pte_page = pte; -- 2.7.4