diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2013-07-23 17:25:57 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-08-29 09:47:32 -0700 |
| commit | 23b625fa111e7358ce84672c4444c068b2b1e204 (patch) | |
| tree | 592c16d7d53e3034a324f8132f0930af74c1c89c /kernel/trace/trace.c | |
| parent | e2d4dbe02175e54616fe52c4e9c367199f8ecdaa (diff) | |
tracing: Change tracing_pipe_fops() to rely on tracing_get_cpu()
commit 15544209cb0b5312e5220a9337a1fe61d1a1f2d9 upstream.
tracing_open_pipe() is racy, the memory inode->i_private points to
can be already freed.
Change debugfs_create_file("trace_pipe", data) callers to to pass
"data = tr", tracing_open_pipe() can use tracing_get_cpu().
Link: http://lkml.kernel.org/r/20130723152557.GA23717@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f064dfb973f..8e8bb0e2548 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3950,8 +3950,7 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf, static int tracing_open_pipe(struct inode *inode, struct file *filp) { - struct trace_cpu *tc = inode->i_private; - struct trace_array *tr = tc->tr; + struct trace_array *tr = inode->i_private; struct trace_iterator *iter; int ret = 0; @@ -3997,9 +3996,9 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) if (trace_clocks[tr->clock_id].in_ns) iter->iter_flags |= TRACE_FILE_TIME_IN_NS; - iter->cpu_file = tc->cpu; - iter->tr = tc->tr; - iter->trace_buffer = &tc->tr->trace_buffer; + iter->tr = tr; + iter->trace_buffer = &tr->trace_buffer; + iter->cpu_file = tracing_get_cpu(inode); mutex_init(&iter->mutex); filp->private_data = iter; @@ -4022,8 +4021,7 @@ fail: static int tracing_release_pipe(struct inode *inode, struct file *file) { struct trace_iterator *iter = file->private_data; - struct trace_cpu *tc = inode->i_private; - struct trace_array *tr = tc->tr; + struct trace_array *tr = inode->i_private; mutex_lock(&trace_types_lock); @@ -5563,7 +5561,7 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu) /* per cpu trace_pipe */ trace_create_cpu_file("trace_pipe", 0444, d_cpu, - &data->trace_cpu, cpu, &tracing_pipe_fops); + tr, cpu, &tracing_pipe_fops); /* per cpu trace */ trace_create_cpu_file("trace", 0644, d_cpu, @@ -6149,7 +6147,7 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) (void *)&tr->trace_cpu, &tracing_fops); trace_create_file("trace_pipe", 0444, d_tracer, - (void *)&tr->trace_cpu, &tracing_pipe_fops); + tr, &tracing_pipe_fops); trace_create_file("buffer_size_kb", 0644, d_tracer, (void *)&tr->trace_cpu, &tracing_entries_fops); |