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| author | Hugh Dickins <hughd@google.com> | 2021-05-15 02:27:22 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-05-15 04:41:32 +0200 |
| commit | 628622904b8d229591134e44efd6608a7541eb89 (patch) | |
| tree | 94a2315b50117f96e1f732ed698df1b6f70a1ea1 /mm/ksm.c | |
| parent | userfaultfd: release page in error path to avoid BUG_ON (diff) | |
| download | linux-628622904b8d229591134e44efd6608a7541eb89.tar.xz linux-628622904b8d229591134e44efd6608a7541eb89.zip | |
ksm: revert "use GET_KSM_PAGE_NOLOCK to get ksm page in remove_rmap_item_from_tree()"
This reverts commit 3e96b6a2e9ad929a3230a22f4d64a74671a0720b. General
Protection Fault in rmap_walk_ksm() under memory pressure:
remove_rmap_item_from_tree() needs to take page lock, of course.
Link: https://lkml.kernel.org/r/alpine.LSU.2.11.2105092253500.1127@eggly.anvils
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | mm/ksm.c | 3 |
1 files changed, 2 insertions, 1 deletions
@@ -776,11 +776,12 @@ static void remove_rmap_item_from_tree(struct rmap_item *rmap_item) struct page *page; stable_node = rmap_item->head; - page = get_ksm_page(stable_node, GET_KSM_PAGE_NOLOCK); + page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK); if (!page) goto out; hlist_del(&rmap_item->hlist); + unlock_page(page); put_page(page); if (!hlist_empty(&stable_node->hlist)) |