From: Jason Gunthorpe <jgg@mellanox.com>
Date: Wed, 11 Mar 2020 17:03:33 -0300
Subject: mm/hmm: do not check pmd_protnone twice in hmm_vma_handle_pmd()
Git-commit: 24cee8ab41eec51ea4cabd19c311719038084648
Patch-mainline: v5.7-rc1
References: jsc#SLE-16387
pmd_to_hmm_pfn_flags() already checks it and makes the cpu flags 0. If no
fault is requested then the pfns should be returned with the not valid
flags.
It should not unconditionally fault if faulting is not requested.
Fixes: 2aee09d8c116 ("mm/hmm: change hmm_vma_fault() to allow write fault on page basis")
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
mm/hmm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -226,7 +226,7 @@ static int hmm_vma_handle_pmd(struct mm_
hmm_range_need_fault(hmm_vma_walk, pfns, npages, cpu_flags,
&fault, &write_fault);
- if (pmd_protnone(pmd) || fault || write_fault)
+ if (fault || write_fault)
return hmm_vma_walk_hole_(addr, end, fault, write_fault, walk);
pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);