[PATCH 0/2] mm: madvise: return exact bytes advised with process_madvise under error

From: Charan Teja Kalla
Date: Wed Mar 23 2022 - 11:24:52 EST


Under error conditions, process_madvise() is not returning the exact
bytes processed in a iovec element thus user may repeat the advise on
vma ranges contained in the iovec element despite those ranges are
already processed. This problem is partially solved with commit
08095d6310a7 ("mm: madvise: skip unmapped vma holes passed to
process_madvise") for ENOMEM return types. These patches try to solve
the problem for other error return types.

Starting this as new discussion, as the back ground for these changes
are coming from below patches, which are already merged into linus tree:
1) https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5bd009c7c9a9e888077c07535dc0c70aeab242c3
2) https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=08095d6310a7ce43256b4251577bc66a25c6e1a6

and lore archives for the above changes:
1) V2: https://lore.kernel.org/linux-mm/cover.1647008754.git.quic_charante@xxxxxxxxxxx/
2) V1: https://lore.kernel.org/linux-mm/1646803679-11433-1-git-send-email-quic_charante@xxxxxxxxxxx/

Charan Teja Kalla (1):
Revert "mm: madvise: skip unmapped vma holes passed to
process_madvise"

Charan Teja Reddy (1):
mm: madvise: return exact bytes advised with process_madvise under
error

mm/madvise.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 88 insertions(+), 11 deletions(-)

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2.7.4