The patch titled
Subject: Revert "mm: madvise: skip unmapped vma holes passed to process_madvise"
has been added to the -mm tree. Its filename is
revert-mm-madvise-skip-unmapped-vma-holes-passed-to-process_madvise.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/revert-mm-madvise-skip-unmapped-vma-holes-passed-to-process_madvise.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/revert-mm-madvise-skip-unmapped-vma-holes-passed-to-process_madvise.patch
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------------------------------------------------------
From: Charan Teja Kalla <quic_charante@xxxxxxxxxxx>
Subject: Revert "mm: madvise: skip unmapped vma holes passed to process_madvise"
This reverts commit 08095d6310a7 ("mm: madvise: skip unmapped vma holes
passed to process_madvise") as process_madvise() fails to return the exact
processed bytes in other cases too. As an example: if process_madvise()
hits mlocked pages after processing some initial bytes passed in [start,
end), it just returns EINVAL although some bytes are processed. Thus
making an exception only for ENOMEM is partially fixing the problem of
returning the proper advised bytes.
Thus revert this patch and return proper bytes advised.
Link: https://lkml.kernel.org/r/e73da1304a88b6a8a11907045117cccf4c2b8374.1648046642.git.quic_charante@xxxxxxxxxxx
Fixes: 08095d6310a7ce ("mm: madvise: skip unmapped vma holes passed to process_madvise")
Signed-off-by: Charan Teja Kalla <quic_charante@xxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/madvise.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)
--- a/mm/madvise.c~revert-mm-madvise-skip-unmapped-vma-holes-passed-to-process_madvise
+++ a/mm/madvise.c
@@ -1464,16 +1464,9 @@ SYSCALL_DEFINE5(process_madvise, int, pi
while (iov_iter_count(&iter)) {
iovec = iov_iter_iovec(&iter);
- /*
- * do_madvise returns ENOMEM if unmapped holes are present
- * in the passed VMA. process_madvise() is expected to skip
- * unmapped holes passed to it in the 'struct iovec' list
- * and not fail because of them. Thus treat -ENOMEM return
- * from do_madvise as valid and continue processing.
- */
ret = do_madvise(mm, (unsigned long)iovec.iov_base,
iovec.iov_len, behavior);
- if (ret < 0 && ret != -ENOMEM)
+ if (ret < 0)
break;
iov_iter_advance(&iter, iovec.iov_len);
}
_
Patches currently in -mm which might be from quic_charante@xxxxxxxxxxx are
revert-mm-madvise-skip-unmapped-vma-holes-passed-to-process_madvise.patch
