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-rw-r--r--mm/page_alloc.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bdff85899638..ed91684cb1f5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -217,6 +217,11 @@ static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
int i;
BUG_ON((gfp_flags & (__GFP_WAIT | __GFP_HIGHMEM)) == __GFP_HIGHMEM);
+ /*
+ * clear_highpage() will use KM_USER0, so it's a bug to use __GFP_ZERO
+ * and __GFP_HIGHMEM from hard or soft interrupt context.
+ */
+ BUG_ON((gfp_flags & __GFP_HIGHMEM) && in_interrupt());
for (i = 0; i < (1 << order); i++)
clear_highpage(page + i);
}