diff options
| author | Li Zefan <lizf@cn.fujitsu.com> | 2009-12-08 11:16:11 +0800 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-12-13 18:37:27 +0100 |
| commit | 13f16d209161c95e92aef40e350cc6cf56ac440b (patch) | |
| tree | a8e3bc78c7b07f5dab8776d91642d29ea1783fb8 | |
| parent | fdb372ed4cadbfe9dbba0e932a77d0523682e690 (diff) | |
tracing: Use seq file for trace_clock
The buffer for the output is as small as 64 bytes, so it'll
overflow if we add more clock type. Use seq file instead.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4B1DC4FB.5030407@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
| -rw-r--r-- | kernel/trace/trace.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a6c41cc6328..886268e0d8e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3366,21 +3366,18 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, return cnt; } -static ssize_t tracing_clock_read(struct file *filp, char __user *ubuf, - size_t cnt, loff_t *ppos) +static int tracing_clock_show(struct seq_file *m, void *v) { - char buf[64]; - int bufiter = 0; int i; for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) - bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter, + seq_printf(m, "%s%s%s%s", i ? " " : "", i == trace_clock_id ? "[" : "", trace_clocks[i].name, i == trace_clock_id ? "]" : ""); - bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter, "\n"); + seq_putc(m, '\n'); - return simple_read_from_buffer(ubuf, cnt, ppos, buf, bufiter); + return 0; } static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, @@ -3422,6 +3419,13 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, return cnt; } +static int tracing_clock_open(struct inode *inode, struct file *file) +{ + if (tracing_disabled) + return -ENODEV; + return single_open(file, tracing_clock_show, NULL); +} + static const struct file_operations tracing_max_lat_fops = { .open = tracing_open_generic, .read = tracing_max_lat_read, @@ -3460,8 +3464,10 @@ static const struct file_operations tracing_mark_fops = { }; static const struct file_operations trace_clock_fops = { - .open = tracing_open_generic, - .read = tracing_clock_read, + .open = tracing_clock_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, .write = tracing_clock_write, }; |