From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
This eventually calls into handle_mm_fault() which is a sleeping function.
Release the lock first.
hmm_vma_walk_hole() does not touch the contents of the PUD, so it does not
need the lock.
Fixes: 3afc423632a1 ("mm: pagewalk: add p4d_entry() and pgd_entry()")
Cc: Steven Price <steven.price@xxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
---
mm/hmm.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/mm/hmm.c b/mm/hmm.c
index 9e8f68eb83287a..32dcbfd3908315 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -473,8 +473,8 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
pud = READ_ONCE(*pudp);
if (pud_none(pud)) {
- ret = hmm_vma_walk_hole(start, end, -1, walk);
- goto out_unlock;
+ spin_unlock(ptl);
+ return hmm_vma_walk_hole(start, end, -1, walk);
}
if (pud_huge(pud) && pud_devmap(pud)) {
@@ -483,8 +483,8 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
bool fault, write_fault;
if (!pud_present(pud)) {
- ret = hmm_vma_walk_hole(start, end, -1, walk);
- goto out_unlock;
+ spin_unlock(ptl);
+ return hmm_vma_walk_hole(start, end, -1, walk);
}
i = (addr - range->start) >> PAGE_SHIFT;
@@ -495,9 +495,9 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end,
hmm_range_need_fault(hmm_vma_walk, pfns, npages,
cpu_flags, &fault, &write_fault);
if (fault || write_fault) {
- ret = hmm_vma_walk_hole_(addr, end, fault,
- write_fault, walk);
- goto out_unlock;
+ spin_unlock(ptl);
+ return hmm_vma_walk_hole_(addr, end, fault, write_fault,
+ walk);
}
pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
--
2.25.1
