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| author | Jason Gunthorpe <jgg@mellanox.com> | 2020-03-27 21:00:19 +0100 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2020-03-30 21:58:36 +0200 |
| commit | 846babe85efdda49feba5b169668333dcf3edf25 (patch) | |
| tree | 9b2f00d245028f5a064ab19f338466111415c84e /mm/hmm.c | |
| parent | mm/hmm: use device_private_entry_to_pfn() (diff) | |
| download | linux-846babe85efdda49feba5b169668333dcf3edf25.tar.xz linux-846babe85efdda49feba5b169668333dcf3edf25.zip | |
mm/hmm: do not unconditionally set pfns when returning EBUSY
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")
Link: https://lore.kernel.org/r/20200327200021.29372-8-jgg@ziepe.ca
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'mm/hmm.c')
| -rw-r--r-- | mm/hmm.c | 7 |
1 files changed, 4 insertions, 3 deletions
@@ -250,11 +250,11 @@ 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; } @@ -275,8 +275,10 @@ 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; @@ -494,7 +496,6 @@ 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) { |