From: Jason Gunthorpe jgg@mellanox.com
In hmm_vma_handle_pte() and hmm_vma_walk_hugetlb_entry() if fault happens then -EBUSY will be returned and the pfns input flags will have been destroyed.
For hmm_vma_handle_pte() set HMM_PFN_NONE only on the success returns that don't otherwise store to pfns.
For hmm_vma_walk_hugetlb_entry() all exit paths already set pfns, so remove the redundant store.
Fixes: 2aee09d8c116 ("mm/hmm: change hmm_vma_fault() to allow write fault on page basis") Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Jason Gunthorpe jgg@mellanox.com --- mm/hmm.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/mm/hmm.c b/mm/hmm.c index 3303686bf16d24..dc826898979bc5 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -244,11 +244,11 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, pte_t pte = *ptep; uint64_t orig_pfn = *pfn;
- *pfn = range->values[HMM_PFN_NONE]; if (pte_none(pte)) { required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0); if (required_fault) goto fault; + *pfn = range->values[HMM_PFN_NONE]; return 0; }
@@ -269,8 +269,10 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, }
required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, 0); - if (!required_fault) + if (!required_fault) { + *pfn = range->values[HMM_PFN_NONE]; return 0; + }
if (!non_swap_entry(entry)) goto fault; @@ -488,7 +490,6 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask,
i = (start - range->start) >> PAGE_SHIFT; orig_pfn = range->pfns[i]; - range->pfns[i] = range->values[HMM_PFN_NONE]; cpu_flags = pte_to_hmm_pfn_flags(range, entry); required_fault = hmm_pte_need_fault(hmm_vma_walk, orig_pfn, cpu_flags); if (required_fault) {