tracing: Add free_trace_iter_content() helper function

As the trace iterator is created and used by various interfaces, the clean
up of it needs to be consistent. Create a free_trace_iter_content() helper
function that frees the content of the iterator and use that to clean it
up in all places that it is used.

Link: https://lkml.kernel.org/r/20230715141348.341887497@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Google) 2023-07-15 10:12:15 -04:00
parent 9182b519b8
commit 6bba92881d

View file

@ -4799,6 +4799,25 @@ static const struct seq_operations tracer_seq_ops = {
.show = s_show,
};
/*
* Note, as iter itself can be allocated and freed in different
* ways, this function is only used to free its content, and not
* the iterator itself. The only requirement to all the allocations
* is that it must zero all fields (kzalloc), as freeing works with
* ethier allocated content or NULL.
*/
static void free_trace_iter_content(struct trace_iterator *iter)
{
/* The fmt is either NULL, allocated or points to static_fmt_buf */
if (iter->fmt != static_fmt_buf)
kfree(iter->fmt);
kfree(iter->temp);
kfree(iter->buffer_iter);
mutex_destroy(&iter->mutex);
free_cpumask_var(iter->started);
}
static struct trace_iterator *
__tracing_open(struct inode *inode, struct file *file, bool snapshot)
{
@ -4906,8 +4925,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
fail:
mutex_unlock(&trace_types_lock);
kfree(iter->temp);
kfree(iter->buffer_iter);
free_trace_iter_content(iter);
release:
seq_release_private(inode, file);
return ERR_PTR(-ENOMEM);
@ -4986,11 +5004,7 @@ static int tracing_release(struct inode *inode, struct file *file)
mutex_unlock(&trace_types_lock);
mutex_destroy(&iter->mutex);
free_cpumask_var(iter->started);
kfree(iter->fmt);
kfree(iter->temp);
kfree(iter->buffer_iter);
free_trace_iter_content(iter);
seq_release_private(inode, file);
return 0;
@ -6747,10 +6761,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
mutex_unlock(&trace_types_lock);
free_cpumask_var(iter->started);
kfree(iter->fmt);
kfree(iter->temp);
mutex_destroy(&iter->mutex);
free_trace_iter_content(iter);
kfree(iter);
trace_array_put(tr);