diff options
Diffstat (limited to 'mm/userfaultfd.c')
| -rw-r--r-- | mm/userfaultfd.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 09976745be23..31207b47ea92 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -301,8 +301,23 @@ retry: out_unlock: up_read(&dst_mm->mmap_sem); out: - if (page) + if (page) { + /* + * We encountered an error and are about to free a newly + * allocated huge page. It is possible that there was a + * reservation associated with the page that has been + * consumed. See the routine restore_reserve_on_error + * for details. Unfortunately, we can not call + * restore_reserve_on_error now as it would require holding + * mmap_sem. Clear the PagePrivate flag so that the global + * reserve count will not be incremented in free_huge_page. + * The reservation map will still indicate the reservation + * was consumed and possibly prevent later page allocation. + * This is better than leaking a global reservation. + */ + ClearPagePrivate(page); put_page(page); + } BUG_ON(copied < 0); BUG_ON(err > 0); BUG_ON(!copied && !err); |