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| author | Bryan Lim <foxieflakey@gmail.com> | 2026-08-19 10:08:24 +0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-09-01 20:26:21 -0700 |
| commit | f025ca73decda1f895a4b80b961d3bc88825298a (patch) | |
| tree | d90bd8a5bfdf0036546c8b50079e976e5e65f684 | |
| parent | 2fd4e7693674b17807a6d082feb01a3fbf86f5f8 (diff) | |
| download | linux-f025ca73decda1f895a4b80b961d3bc88825298a.tar.gz linux-f025ca73decda1f895a4b80b961d3bc88825298a.zip | |
userfaultfd: reset err to be 0 when move_pages_ptes succeeded
During move_pages() operation, when move_pages_ptes() returns EAGAIN, the
error code is not cleared even after we processed it. This leads to a
successful retry but then the same pages are retried again due to the
stale error code. This time move fails because pages are already moved,
loop is terminated and move_pages() reports a failure. Clear the error
code once we processes EAGAIN.
Link: https://lore.kernel.org/e1e0b5f8-c3c6-0537-670b-4397f822f980@gmail.com
Fixes: 50944692052b ("userfaultfd: opportunistic TLB-flush batching for present pages in MOVE")
Assisted-by: ChatGPT:GPT-5.6-Luna
Signed-off-by: Bryan Lim <foxieflakey@gmail.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/userfaultfd.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 23fb68fce000..74f04c323c50 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -2171,8 +2171,10 @@ static ssize_t move_pages(struct userfaultfd_ctx *ctx, unsigned long dst_start, } if (err) { - if (err == -EAGAIN) + if (err == -EAGAIN) { + err = 0; continue; + } break; } |