From 1f602f2ab0e50870a0188efcfabff105b8db48d6 Mon Sep 17 00:00:00 2001 From: Charan Teja Kalla Date: Fri, 1 Apr 2022 11:28:12 -0700 Subject: [PATCH] Revert "mm: madvise: skip unmapped vma holes passed to process_madvise" commit e6b0a7b357659c332231621e4315658d062c23ee upstream. 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@quicinc.com Fixes: 08095d6310a7ce ("mm: madvise: skip unmapped vma holes passed to process_madvise") Signed-off-by: Charan Teja Kalla Acked-by: Michal Hocko Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: David Rientjes Cc: Nadav Amit Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/madvise.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/mm/madvise.c b/mm/madvise.c index 14fb76db67740..e97e6a93d5aee 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1426,16 +1426,9 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, 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); } -- 2.50.1