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| author |   Charan Teja Kalla <quic_charante@quicinc.com> | 2022-03-22 14:46:48 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 15:57:10 -0700 |
| commit | 08095d6310a7ce43256b4251577bc66a25c6e1a6 (patch) | |
| tree | 3ef5590f09453846a696b7c7885e19e5bf1389fd /mm/madvise.c | |
| parent | mm: madvise: return correct bytes advised with process_madvise (diff) | |
| download | linux-dev-08095d6310a7ce43256b4251577bc66a25c6e1a6.tar.xz linux-dev-08095d6310a7ce43256b4251577bc66a25c6e1a6.zip | |
mm: madvise: skip unmapped vma holes passed to process_madvise
The process_madvise() system call is expected to skip holes in vma passed
through 'struct iovec' vector list. But do_madvise, which
process_madvise() calls for each vma, returns ENOMEM in case of unmapped
holes, despite the VMA is processed.
Thus process_madvise() should treat ENOMEM as expected and consider the
VMA passed to as processed and continue processing other vma's in the
vector list. Returning -ENOMEM to user, despite the VMA is processed,
will be unable to figure out where to start the next madvise.
Link: https://lkml.kernel.org/r/4f091776142f2ebf7b94018146de72318474e686.1647008754.git.quic_charante@quicinc.com
Fixes: ecb8ac8b1f14("mm/madvise: introduce process_madvise() syscall: an external memory hinting API")
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/madvise.c')
| -rw-r--r-- | mm/madvise.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/mm/madvise.c b/mm/madvise.c index df59937c75e3..89490c859c3f 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1428,9 +1428,16 @@ 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) + if (ret < 0 && ret != -ENOMEM) break; iov_iter_advance(&iter, iovec.iov_len); } |