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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-28 22:20:24 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-28 22:20:24 +0300 |
| commit | 6581ccf03e717926be97dc3d27182ce351232f3c (patch) | |
| tree | c4ca1b6867a5d72c755e5786130e1c97f5236cac /mm | |
| parent | 77b1a7f7a05c673c187894b4ae898a8c0cdc776c (diff) | |
| download | linux-6581ccf03e717926be97dc3d27182ce351232f3c.tar.xz | |
mm: fix __access_remote_vm() GUP failure case
Commit ca5e863233e8 ("mm/gup: remove vmas parameter from
get_user_pages_remote()") removed the vma argument from GUP handling,
and instead added a helper function (get_user_page_vma_remote()) that
looks it up separately using 'vma_lookup()'. And then converted
existing users that needed a vma to use the helper instead.
However, the helper function intentionally acts exactly like the old
get_user_pages_remote() did, and only fills in 'vma' on successful page
lookup. Fine so far.
However, __access_remote_vm() wants the vma even for the unsuccessful
case, and used to do a
vma = vma_lookup(mm, addr);
explicitly to look it up when the get_user_page() failed.
However, that conversion commit incorrectly removed that vma lookup,
thinking that get_user_page_vma_remote() would have done it. Not so.
So add the vma_lookup() back in.
Fixes: ca5e863233e8 ("mm/gup: remove vmas parameter from get_user_pages_remote()")
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index f758f59f3704..11882189864e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5592,6 +5592,7 @@ int __access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf, * Check if this is a VM_IO | VM_PFNMAP VMA, which * we can access using slightly different code. */ + vma = vma_lookup(mm, addr); if (!vma) break; if (vma->vm_ops && vma->vm_ops->access) |