diff options
| author | Davidlohr Bueso | 2014-04-03 14:47:27 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2014-04-03 16:20:59 -0700 |
| commit | 7b24d8616be33616efd41ff67d3c76362c60ca84 (patch) | |
| tree | 6bc0558e36c54f66f73e33a4891e9e5ead924104 /include | |
| parent | 1406ec9ba6c65cb69e9243bff07ca3f51e2525e0 (diff) | |
mm, hugetlb: fix race in region tracking
There is a race condition if we map a same file on different processes.
Region tracking is protected by mmap_sem and hugetlb_instantiation_mutex.
When we do mmap, we don't grab a hugetlb_instantiation_mutex, but only
mmap_sem (exclusively). This doesn't prevent other tasks from modifying
the region structure, so it can be modified by two processes
concurrently.
To solve this, introduce a spinlock to resv_map and make region
manipulation function grab it before they do actual work.
[davidlohr@hp.com: updated changelog]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/hugetlb.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index f62c2f6c6059..5b337cf8fb86 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -27,6 +27,7 @@ struct hugepage_subpool { struct resv_map { struct kref refs; + spinlock_t lock; struct list_head regions; }; extern struct resv_map *resv_map_alloc(void); |