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>
This commit is contained in:
Li Zefan 2009-12-08 11:16:11 +08:00 committed by Frederic Weisbecker
parent fdb372ed4c
commit 13f16d2091

View file

@ -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,
};