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| author | Tejun Heo <tj@kernel.org> | 2013-08-13 11:01:54 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2013-08-13 11:01:54 -0400 |
| commit | b77d7b6088377998ebf65eaea5e51008c2d75e94 (patch) | |
| tree | cab54dcd2c0639b127eb7920f6459d5f84695da0 /kernel/events | |
| parent | 0ae78e0bf10ac38ab53548e18383afc9997eca22 (diff) | |
| download | lwn-b77d7b6088377998ebf65eaea5e51008c2d75e94.tar.gz lwn-b77d7b6088377998ebf65eaea5e51008c2d75e94.zip | |
cgroup: cgroup_css_from_dir() now should be called with RCU read locked
cgroup->subsys[] will become RCU protected and thus all cgroup_css()
usages should either be under RCU read lock or cgroup_mutex. This
patch updates cgroup_css_from_dir() which returns the matching
cgroup_subsys_state given a directory file and subsys_id so that it
requires RCU read lock and updates its sole user
perf_cgroup_connect().
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index c199c4f24910..23261f957713 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -591,6 +591,8 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event, if (!f.file) return -EBADF; + rcu_read_lock(); + css = cgroup_css_from_dir(f.file, perf_subsys_id); if (IS_ERR(css)) { ret = PTR_ERR(css); @@ -617,6 +619,7 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event, ret = -EINVAL; } out: + rcu_read_unlock(); fdput(f); return ret; } |