diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2014-10-10 00:27:48 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-10 04:25:56 +0200 |
| commit | 6b6482bbf64ef6f6dbc8b52f7a7cf88a0498bd51 (patch) | |
| tree | 026e6f1a304c6a9f4da4462427e21fa3178fddfa /mm/mempolicy.c | |
| parent | mempolicy: sanitize the usage of get_task_policy() (diff) | |
| download | linux-6b6482bbf64ef6f6dbc8b52f7a7cf88a0498bd51.tar.xz linux-6b6482bbf64ef6f6dbc8b52f7a7cf88a0498bd51.zip | |
mempolicy: remove the "task" arg of vma_policy_mof() and simplify it
1. vma_policy_mof(task) is simply not safe unless task == current,
it can race with do_exit()->mpol_put(). Remove this arg and update
its single caller.
2. vma can not be NULL, remove this check and simplify the code.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
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 'mm/mempolicy.c')
| -rw-r--r-- | mm/mempolicy.c | 25 |
1 files changed, 11 insertions, 14 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index b86b08e77b8d..ad27bbc757bf 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1646,27 +1646,24 @@ struct mempolicy *get_vma_policy(struct task_struct *task, return pol; } -bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma) +bool vma_policy_mof(struct vm_area_struct *vma) { - struct mempolicy *pol = NULL; - - if (vma) { - if (vma->vm_ops && vma->vm_ops->get_policy) { - bool ret = false; + struct mempolicy *pol; - pol = vma->vm_ops->get_policy(vma, vma->vm_start); - if (pol && (pol->flags & MPOL_F_MOF)) - ret = true; - mpol_cond_put(pol); + if (vma->vm_ops && vma->vm_ops->get_policy) { + bool ret = false; - return ret; - } + pol = vma->vm_ops->get_policy(vma, vma->vm_start); + if (pol && (pol->flags & MPOL_F_MOF)) + ret = true; + mpol_cond_put(pol); - pol = vma->vm_policy; + return ret; } + pol = vma->vm_policy; if (!pol) - pol = get_task_policy(task); + pol = get_task_policy(current); return pol->flags & MPOL_F_MOF; } |