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authorLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>2013-05-24 15:55:18 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-06-07 12:49:13 -0700
commit11e88c5e7bbb812ed25f1e6a8e98d334f0e7dc38 (patch)
treef15d8065f22fa06aaba34d3e3b5dee7f8fbe867a /mm
parent03908608b9a65cb8564ba19caa7608dd470ec4cb (diff)
downloadlinux-linaro-stable-11e88c5e7bbb812ed25f1e6a8e98d334f0e7dc38.tar.gz
mm compaction: fix of improper cache flush in migration code
commit c2cc499c5bcf9040a738f49e8051b42078205748 upstream. Page 'new' during MIGRATION can't be flushed with flush_cache_page(). Using flush_cache_page(vma, addr, pfn) is justified only if the page is already placed in process page table, and that is done right after flush_cache_page(). But without it the arch function has no knowledge of process PTE and does nothing. Besides that, flush_cache_page() flushes an application cache page, but the kernel has a different page virtual address and dirtied it. Replace it with flush_dcache_page(new) which is the proper usage. The old page is flushed in try_to_unmap_one() before migration. This bug takes place in Sead3 board with M14Kc MIPS CPU without cache aliasing (but Harvard arch - separate I and D cache) in tight memory environment (128MB) each 1-3days on SOAK test. It fails in cc1 during kernel build (SIGILL, SIGBUS, SIGSEG) if CONFIG_COMPACTION is switched ON. Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Leonid Yegoshin <yegoshin@mips.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/migrate.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 11072383ae12..37cd07b90da6 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -145,7 +145,7 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
if (PageHuge(new))
pte = pte_mkhuge(pte);
#endif
- flush_cache_page(vma, addr, pte_pfn(pte));
+ flush_dcache_page(new);
set_pte_at(mm, addr, ptep, pte);
if (PageHuge(new)) {