Messages in this thread Patch in this message | | | Date | Sun, 20 Oct 2013 22:44:34 -0400 | From | Steven Rostedt <> | Subject | [for-next][PATCH 5/6] ftrace: Narrow down the protected area of graph_lock |
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From: Namhyung Kim <namhyung.kim@lge.com>
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> --- kernel/trace/ftrace.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 0ff3449..26a229a 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; } -- 1.8.4.rc3
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