From d456fb9e5254df433d4806769d7ff75d80d66aa4 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Fri, 4 Sep 2015 15:48:07 -0700
Subject: [PATCH] mremap: don't do mm_populate(new_addr) on failure
move_vma() sets *locked even if move_page_tables() or ->mremap() fails,
change sys_mremap() to check "ret & ~PAGE_MASK".
I think we should simply remove the VM_LOCKED code in move_vma(), that is
why this patch doesn't change move_vma(). But this needs more cleanups.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/mremap.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/mremap.c b/mm/mremap.c
index 3310378bb60f..7dcf7b42068e 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -578,8 +578,10 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
ret = move_vma(vma, addr, old_len, new_len, new_addr, &locked);
}
out:
- if (ret & ~PAGE_MASK)
+ if (ret & ~PAGE_MASK) {
vm_unacct_memory(charged);
+ locked = 0;
+ }
up_write(¤t->mm->mmap_sem);
if (locked && new_len > old_len)
mm_populate(new_addr + old_len, new_len - old_len);
--
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