diff options
| author | David Hildenbrand <david@redhat.com> | 2024-06-05 11:17:10 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-06-15 19:43:05 +0200 |
| commit | 384a746bb55960aa5ffb3a67de08f11fc2f51042 (patch) | |
| tree | 9ccb04eb8cff6811cfd609be1deb332082e158f1 /mm/page_alloc.c | |
| parent | mm/page_table_check: fix crash on ZONE_DEVICE (diff) | |
| download | linux-384a746bb55960aa5ffb3a67de08f11fc2f51042.tar.xz linux-384a746bb55960aa5ffb3a67de08f11fc2f51042.zip | |
Revert "mm: init_mlocked_on_free_v3"
There was insufficient review and no agreement that this is the right
approach.
There are serious flaws with the implementation that make processes using
mlock() not even work with simple fork() [1] and we get reliable crashes
when rebooting.
Further, simply because we might be unmapping a single PTE of a large
mlocked folio, we shouldn't zero out the whole folio.
... especially because the code can also *corrupt* urelated memory because
kernel_init_pages(page, folio_nr_pages(folio));
Could end up writing outside of the actual folio if we work with a tail
page.
Let's revert it. Once there is agreement that this is the right approach,
the issues were fixed and there was reasonable review and proper testing,
we can consider it again.
[1] https://lkml.kernel.org/r/4da9da2f-73e4-45fd-b62f-a8a513314057@redhat.com
Link: https://lkml.kernel.org/r/20240605091710.38961-1-david@redhat.com
Fixes: ba42b524a040 ("mm: init_mlocked_on_free_v3")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: David Wang <00107082@163.com>
Closes: https://lore.kernel.org/lkml/20240528151340.4282-1-00107082@163.com/
Reported-by: Lance Yang <ioworker0@gmail.com>
Closes: https://lkml.kernel.org/r/20240601140917.43562-1-ioworker0@gmail.com
Acked-by: Lance Yang <ioworker0@gmail.com>
Cc: York Jasper Niebuhr <yjnworkstation@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 222299b5c0e6..7300aa9f14b0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1016,7 +1016,7 @@ static inline bool should_skip_kasan_poison(struct page *page) return page_kasan_tag(page) == KASAN_TAG_KERNEL; } -void kernel_init_pages(struct page *page, int numpages) +static void kernel_init_pages(struct page *page, int numpages) { int i; |