From 20cbc972617069c1ed434f62151e4de57d26ea46 Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Sat, 5 Jul 2008 12:29:05 -0700
Subject: [PATCH] Fix clear_refs_write() use of struct mm_walk
Don't use a static entry, so as to prevent races during concurrent use
of this function.
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/proc/task_mmu.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index ab8ccc9d14ff..05053d701ac5 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -476,10 +476,10 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
return -ESRCH;
mm = get_task_mm(task);
if (mm) {
- static struct mm_walk clear_refs_walk;
- memset(&clear_refs_walk, 0, sizeof(clear_refs_walk));
- clear_refs_walk.pmd_entry = clear_refs_pte_range;
- clear_refs_walk.mm = mm;
+ struct mm_walk clear_refs_walk = {
+ .pmd_entry = clear_refs_pte_range,
+ .mm = mm,
+ };
down_read(&mm->mmap_sem);
for (vma = mm->mmap; vma; vma = vma->vm_next) {
clear_refs_walk.private = vma;
--
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