From: Doug Doan <dougd@xxxxxxxx>
When a copy-on-write occurs, we take one of two paths in handle_mm_fault:
through handle_pte_fault for normal pages, or through hugetlb_fault for huge pages.
In the normal page case, we eventually get to do_wp_page and call mmu notifiers
via ptep_clear_flush_notify. There is no callout to the mmmu notifiers in the
huge page case. This patch fixes that.
Signed-off-by: Doug Doan <dougd@xxxxxxxx>
---
--- mm/hugetlb.c.orig 2010-05-27 13:07:58.569546314 -0700
+++ mm/hugetlb.c 2010-05-26 14:41:06.449296524 -0700
@@ -2345,11 +2345,17 @@ retry_avoidcopy:
ptep = huge_pte_offset(mm, address & huge_page_mask(h));
if (likely(pte_same(huge_ptep_get(ptep), pte))) {
/* Break COW */
+ mmu_notifier_invalidate_range_start(mm,
+ address & huge_page_mask(h),
+ (address & huge_page_mask(h)) + huge_page_size(h));
huge_ptep_clear_flush(vma, address, ptep);
set_huge_pte_at(mm, address, ptep,
make_huge_pte(vma, new_page, 1));
/* Make the old page be freed below */
new_page = old_page;
+ mmu_notifier_invalidate_range_end(mm,
+ address & huge_page_mask(h),
+ (address & huge_page_mask(h)) + huge_page_size(h));
}
page_cache_release(new_page);
page_cache_release(old_page);