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authorZi Yan <ziy@nvidia.com>2024-03-07 13:18:54 -0500
committerAndrew Morton <akpm@linux-foundation.org>2024-03-12 13:07:17 -0700
commit2394aef616cf38fbf2e797c6845ccd35d76ce256 (patch)
treef76d2d2dc05ec05bdbe3566f12359a3a71d5ce27
parent1412ecb3d256e5d23c6bd150e110cef6e3736844 (diff)
mm/huge_memory: skip invalid debugfs new_order input for folio split
User can put arbitrary new_order via debugfs for folio split test. Although new_order check is added to split_huge_page_to_list_order() in the prior commit, these two additional checks can avoid unnecessary folio locking and split_folio_to_order() calls. Link: https://lkml.kernel.org/r/20240307181854.138928-2-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/linux-mm/7dda9283-b437-4cf8-ab0d-83c330deb9c0@moroto.mountain/ Cc: David Hildenbrand <david@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--mm/huge_memory.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 57fca7bffd20..9859aa4f7553 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3486,6 +3486,9 @@ static int split_huge_pages_pid(int pid, unsigned long vaddr_start,
if (!is_transparent_hugepage(folio))
goto next;
+ if (new_order >= folio_order(folio))
+ goto next;
+
total++;
/*
* For folios with private, split_huge_page_to_list_to_order()
@@ -3553,6 +3556,9 @@ static int split_huge_pages_in_file(const char *file_path, pgoff_t off_start,
total++;
nr_pages = folio_nr_pages(folio);
+ if (new_order >= folio_order(folio))
+ goto next;
+
if (!folio_trylock(folio))
goto next;