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| author | Tejun Heo <tj@kernel.org> | 2012-11-06 09:16:53 -0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2012-11-06 12:28:04 -0800 |
| commit | 4b1c7840b7d01b14a1a00fa0e61b761d4391ba67 (patch) | |
| tree | 1e93e0a8a0bb6fb2f5934a58a6eb32b3077b18b8 /security/device_cgroup.c | |
| parent | 5b805f2a7675634fbdf9ac1c9b2256905ab2ea68 (diff) | |
| download | linux-4b1c7840b7d01b14a1a00fa0e61b761d4391ba67.tar.gz linux-4b1c7840b7d01b14a1a00fa0e61b761d4391ba67.tar.bz2 linux-4b1c7840b7d01b14a1a00fa0e61b761d4391ba67.zip | |
device_cgroup: add lockdep asserts
device_cgroup uses RCU safe ->exceptions list which is write-protected
by devcgroup_mutex and has had some issues using locking correctly.
Add lockdep asserts to utility functions so that future errors can be
easily detected.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Diffstat (limited to 'security/device_cgroup.c')
| -rw-r--r-- | security/device_cgroup.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/security/device_cgroup.c b/security/device_cgroup.c index b08d20c66c2e..78a16f5b7275 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -82,6 +82,8 @@ static int dev_exceptions_copy(struct list_head *dest, struct list_head *orig) { struct dev_exception_item *ex, *tmp, *new; + lockdep_assert_held(&devcgroup_mutex); + list_for_each_entry(ex, orig, list) { new = kmemdup(ex, sizeof(*ex), GFP_KERNEL); if (!new) @@ -107,6 +109,8 @@ static int dev_exception_add(struct dev_cgroup *dev_cgroup, { struct dev_exception_item *excopy, *walk; + lockdep_assert_held(&devcgroup_mutex); + excopy = kmemdup(ex, sizeof(*ex), GFP_KERNEL); if (!excopy) return -ENOMEM; @@ -137,6 +141,8 @@ static void dev_exception_rm(struct dev_cgroup *dev_cgroup, { struct dev_exception_item *walk, *tmp; + lockdep_assert_held(&devcgroup_mutex); + list_for_each_entry_safe(walk, tmp, &dev_cgroup->exceptions, list) { if (walk->type != ex->type) continue; @@ -163,6 +169,8 @@ 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); @@ -298,6 +306,10 @@ static int may_access(struct dev_cgroup *dev_cgroup, struct dev_exception_item *ex; bool match = false; + rcu_lockdep_assert(rcu_read_lock_held() || + lockdep_is_held(&devcgroup_mutex), + "device_cgroup::may_access() called without proper synchronization"); + list_for_each_entry_rcu(ex, &dev_cgroup->exceptions, list) { if ((refex->type & DEV_BLOCK) && !(ex->type & DEV_BLOCK)) continue; |