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| author | Geyslan G. Bem <geyslan@gmail.com> | 2013-11-06 20:02:51 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-11-06 21:26:54 +0100 |
| commit | d6d3523caab75196560c85aae80cb8f4a8e380ea (patch) | |
| tree | c051e62d5e1579a530ed2966d1ee38f5c7a8dce8 /kernel | |
| parent | tracing: Add helper function tracing_is_disabled() (diff) | |
| download | linux-d6d3523caab75196560c85aae80cb8f4a8e380ea.tar.xz linux-d6d3523caab75196560c85aae80cb8f4a8e380ea.zip | |
tracing: Do not assign filp->private_data to freed memory
In system_tr_open(), the filp->private_data can be assigned the 'dir'
variable even if it was freed. This is on the error path, and is
harmless because the error return code will prevent filp->private_data
from being used. But for correctness, we should not assign it to
a recently freed variable, as that can cause static tools to give
false warnings.
Also have both subsystem_open() and system_tr_open() return -ENODEV
if tracing has been disabled.
Link: http://lkml.kernel.org/r/1383764571-7318-1-git-send-email-geyslan@gmail.com
Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_events.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 043f833246a0..f919a2e21bf3 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1062,6 +1062,9 @@ static int subsystem_open(struct inode *inode, struct file *filp) struct trace_array *tr; int ret; + if (tracing_is_disabled()) + return -ENODEV; + /* Make sure the system still exists */ mutex_lock(&trace_types_lock); mutex_lock(&event_mutex); @@ -1108,6 +1111,9 @@ static int system_tr_open(struct inode *inode, struct file *filp) struct trace_array *tr = inode->i_private; int ret; + if (tracing_is_disabled()) + return -ENODEV; + if (trace_array_get(tr) < 0) return -ENODEV; @@ -1124,11 +1130,12 @@ static int system_tr_open(struct inode *inode, struct file *filp) if (ret < 0) { trace_array_put(tr); kfree(dir); + return ret; } filp->private_data = dir; - return ret; + return 0; } static int subsystem_release(struct inode *inode, struct file *file) |