diff options
| author | Namhyung Kim <namhyung.kim@lge.com> | 2013-10-14 17:24:25 +0900 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2013-10-18 22:20:33 -0400 |
| commit | 6a10108bdbbfb66e5c431fd1056534e9717d34eb (patch) | |
| tree | a9d30739ba6bcf62c19418759c4c679e008ae258 /kernel/trace/ftrace.c | |
| parent | faf982a60f7c985808f761cff5d508f21c691790 (diff) | |
ftrace: Narrow down the protected area of graph_lock
The parser set up is just a generic utility that uses local variables
allocated by the function. There's no need to hold the graph_lock for
this set up.
This also makes the code simpler.
Link: http://lkml.kernel.org/r/1381739066-7531-4-git-send-email-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 22 |
1 files changed, 9 insertions, 13 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 0ff3449b4272..26a229ab0c19 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3973,37 +3973,33 @@ ftrace_graph_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_parser parser; - ssize_t read, ret; + ssize_t read, ret = 0; struct ftrace_graph_data *fgd = file->private_data; if (!cnt) return 0; - mutex_lock(&graph_lock); - - if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) { - ret = -ENOMEM; - goto out_unlock; - } + if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) + return -ENOMEM; read = trace_get_user(&parser, ubuf, cnt, ppos); if (read >= 0 && trace_parser_loaded((&parser))) { parser.buffer[parser.idx] = 0; + mutex_lock(&graph_lock); + /* we allow only one expression at a time */ ret = ftrace_set_func(fgd->table, fgd->count, fgd->size, parser.buffer); - if (ret) - goto out_free; + + mutex_unlock(&graph_lock); } - ret = read; + if (!ret) + ret = read; -out_free: trace_parser_put(&parser); -out_unlock: - mutex_unlock(&graph_lock); return ret; } |