X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fmremap.c;h=20a07dba6be04fb20f21bbac5ed1e289a8ccd354;hb=81ac3ad9061dd9cd490ee92f0c5316a14d77ce18;hp=646de959aa5873b44b1a7f978a5e99524b7fa09c;hpb=046c68842bce6b77509cf56e94a561029124b0ce;p=safe%2Fjmp%2Flinux-2.6

diff --git a/mm/mremap.c b/mm/mremap.c
index 646de95..20a07db 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -11,6 +11,7 @@
 #include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/shm.h>
+#include <linux/ksm.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
 #include <linux/capability.h>
@@ -174,6 +175,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
 	unsigned long excess = 0;
 	unsigned long hiwater_vm;
 	int split = 0;
+	int err;
 
 	/*
 	 * We'd prefer to avoid failure later on in do_munmap:
@@ -182,6 +184,18 @@ static unsigned long move_vma(struct vm_area_struct *vma,
 	if (mm->map_count >= sysctl_max_map_count - 3)
 		return -ENOMEM;
 
+	/*
+	 * Advise KSM to break any KSM pages in the area to be moved:
+	 * it would be confusing if they were to turn up at the new
+	 * location, where they happen to coincide with different KSM
+	 * pages recently unmapped.  But leave vma->vm_flags as it was,
+	 * so KSM can come around to merge on vma and new_vma afterwards.
+	 */
+	err = ksm_madvise(vma, old_addr, old_addr + old_len,
+						MADV_UNMERGEABLE, &vm_flags);
+	if (err)
+		return err;
+
 	new_pgoff = vma->vm_pgoff + ((old_addr - vma->vm_start) >> PAGE_SHIFT);
 	new_vma = copy_vma(&vma, new_addr, new_len, new_pgoff);
 	if (!new_vma)
@@ -420,9 +434,9 @@ out_nc:
 	return ret;
 }
 
-asmlinkage unsigned long sys_mremap(unsigned long addr,
-	unsigned long old_len, unsigned long new_len,
-	unsigned long flags, unsigned long new_addr)
+SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
+		unsigned long, new_len, unsigned long, flags,
+		unsigned long, new_addr)
 {
 	unsigned long ret;