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authorMichal Hocko <mhocko@suse.com>2018-08-17 15:46:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-17 16:20:29 -0700
commit9ea9a68064035dee70f465f605a3e63990e33bd9 (patch)
treebab1e0e6b994cf84e92d31162241d012ea2e08fb /mm
parent974e6d66b6b5c6e2d6a3ccc18b2f9a0b472be5b4 (diff)
mm: drop VM_BUG_ON from __get_free_pages
There is no real reason to blow up just because the caller doesn't know that __get_free_pages cannot return highmem pages. Simply fix that up silently. Even if we have some confused users such a fixup will not be harmful. [akpm@linux-foundation.org: mask off __GFP_HIGHMEM] Link: http://lkml.kernel.org/r/20180622162841.25114-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Jiankang Chen <chenjiankang1@huawei.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Yisheng Xie <xieyisheng1@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/page_alloc.c12
1 files changed, 4 insertions, 8 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0303a3b24610..e1517bb143dc 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4404,19 +4404,15 @@ out:
EXPORT_SYMBOL(__alloc_pages_nodemask);
/*
- * Common helper functions.
+ * Common helper functions. Never use with __GFP_HIGHMEM because the returned
+ * address cannot represent highmem pages. Use alloc_pages and then kmap if
+ * you need to access high mem.
*/
unsigned long __get_free_pages(gfp_t gfp_mask, unsigned int order)
{
struct page *page;
- /*
- * __get_free_pages() returns a virtual address, which cannot represent
- * a highmem page
- */
- VM_BUG_ON((gfp_mask & __GFP_HIGHMEM) != 0);
-
- page = alloc_pages(gfp_mask, order);
+ page = alloc_pages(gfp_mask & ~__GFP_HIGHMEM, order);
if (!page)
return 0;
return (unsigned long) page_address(page);