mmu_notifier: Provide invalidate_range for move_page_tables
Move page tables also needs to invalidate the external references
and hold new references off while moving page table entries.
This is already guaranteed by holding a writelock
on mmap_sem for get_user_pages() but follow_page() is not subject to
the mmap_sem locking.
Signed-off-by: Christoph Lameter <[EMAIL PROTECTED]>
---
mm/mremap.c | 4 ++++
1 file changed, 4 insertions(+)
Index: linux-2.6/mm/mremap.c
===================================================================
--- linux-2.6.orig/mm/mremap.c 2008-01-25 14:25:31.000000000 -0800
+++ linux-2.6/mm/mremap.c 2008-01-31 17:54:19.000000000 -0800
@@ -18,6 +18,7 @@
#include <linux/highmem.h>
#include <linux/security.h>
#include <linux/syscalls.h>
+#include <linux/mmu_notifier.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
@@ -130,6 +131,8 @@ unsigned long move_page_tables(struct vm
old_end = old_addr + len;
flush_cache_range(vma, old_addr, old_end);
+ mmu_notifier(invalidate_range_begin, vma->vm_mm,
+ old_addr, old_addr + len, 0);
for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
cond_resched();
next = (old_addr + PMD_SIZE) & PMD_MASK;
@@ -150,6 +153,7 @@ unsigned long move_page_tables(struct vm
move_ptes(vma, old_pmd, old_addr, old_addr + extent,
new_vma, new_pmd, new_addr);
}
+ mmu_notifier(invalidate_range_end, vma->vm_mm, 0);
return len + old_addr - old_end; /* how much done */
}
--
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