Messages in this thread | | | Date | Wed, 26 Jul 2023 22:42:13 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH v2 2/2] tracing: Add free_trace_iter_content() helper function |
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On Sat, 15 Jul 2023 10:12:15 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> From: "Steven Rostedt (Google)" <rostedt@goodmis.org> > > 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. > > Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Looks good to me.
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
BTW, this adds iter->fmt != static_fmt_buf check. Is it a kind of fix?
Thank you,
> --- > kernel/trace/trace.c | 33 ++++++++++++++++++++++----------- > 1 file changed, 22 insertions(+), 11 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 1c370ffbe062..8775930aa545 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -4815,6 +4815,25 @@ 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) > { > @@ -4922,8 +4941,7 @@ __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); > @@ -5002,11 +5020,7 @@ 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; > @@ -6763,10 +6777,7 @@ 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); > -- > 2.40.1
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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