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| author | Andrew Morton <akpm@osdl.org> | 2006-03-22 00:08:42 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-22 07:54:02 -0800 |
| commit | 6626c5d53bc45c59798628677ba5606f02e371f3 (patch) | |
| tree | 7be40e7709b1887648a649fd6b5c036638c4608b /mm/page_alloc.c | |
| parent | 17cf44064ae744f081309108fa67f0e942b10167 (diff) | |
| download | lwn-6626c5d53bc45c59798628677ba5606f02e371f3.tar.gz lwn-6626c5d53bc45c59798628677ba5606f02e371f3.zip | |
[PATCH] mm: prep_zero_page() in irq is a bug
prep_zero_page() uses KM_USER0 and hence may not be used from IRQ context, at
least for highmem pages.
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 5 |
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); } |