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| author | Jerry Snitselaar <jerry.snitselaar@oracle.com> | 2013-02-21 16:41:31 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-21 17:22:15 -0800 |
| commit | 53eb8c82d581fdd4b389a3e417261f3ae924e603 (patch) | |
| tree | de3893156c17c9ab220e4460630f581c55a0f487 /security | |
| parent | 024e4ec1856d57bb78c06ec903d29dcf716f5f47 (diff) | |
| download | lwn-53eb8c82d581fdd4b389a3e417261f3ae924e603.tar.gz lwn-53eb8c82d581fdd4b389a3e417261f3ae924e603.zip | |
device_cgroup: don't grab mutex in rcu callback
Commit 103a197c0c4e ("security/device_cgroup: lock assert fails in
dev_exception_clean()") grabs devcgroup_mutex to fix assert failure, but
a mutex can't be grabbed in rcu callback. Since there shouldn't be any
other references when css_free is called, mutex isn't needed for list
cleanup in devcgroup_css_free().
Signed-off-by: Jerry Snitselaar <jerry.snitselaar@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'security')
| -rw-r--r-- | security/device_cgroup.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/security/device_cgroup.c b/security/device_cgroup.c index d794abcc4b3b..1c69e38e3a2c 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -159,6 +159,16 @@ static void dev_exception_rm(struct dev_cgroup *dev_cgroup, } } +static void __dev_exception_clean(struct dev_cgroup *dev_cgroup) +{ + struct dev_exception_item *ex, *tmp; + + list_for_each_entry_safe(ex, tmp, &dev_cgroup->exceptions, list) { + list_del_rcu(&ex->list); + kfree_rcu(ex, rcu); + } +} + /** * dev_exception_clean - frees all entries of the exception list * @dev_cgroup: dev_cgroup with the exception list to be cleaned @@ -167,14 +177,9 @@ static void dev_exception_rm(struct dev_cgroup *dev_cgroup, */ static void dev_exception_clean(struct dev_cgroup *dev_cgroup) { - struct dev_exception_item *ex, *tmp; - lockdep_assert_held(&devcgroup_mutex); - list_for_each_entry_safe(ex, tmp, &dev_cgroup->exceptions, list) { - list_del_rcu(&ex->list); - kfree_rcu(ex, rcu); - } + __dev_exception_clean(dev_cgroup); } /* @@ -215,9 +220,7 @@ static void devcgroup_css_free(struct cgroup *cgroup) struct dev_cgroup *dev_cgroup; dev_cgroup = cgroup_to_devcgroup(cgroup); - mutex_lock(&devcgroup_mutex); - dev_exception_clean(dev_cgroup); - mutex_unlock(&devcgroup_mutex); + __dev_exception_clean(dev_cgroup); kfree(dev_cgroup); } |