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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>
This commit is contained in:
Namhyung Kim 2013-10-14 17:24:25 +09:00 committed by Steven Rostedt
parent faf982a60f
commit 6a10108bdb
1 changed files with 9 additions and 13 deletions
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22
kernel/trace/ftrace.c
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@ -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;
}