Commit-ID: 13f16d209161c95e92aef40e350cc6cf56ac440b
Gitweb: http://git.kernel.org/tip/13f16d209161c95e92aef40e350cc6cf56ac440b
Author: Li Zefan <lizf@xxxxxxxxxxxxxx>
AuthorDate: Tue, 8 Dec 2009 11:16:11 +0800
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Sun, 13 Dec 2009 18:37:27 +0100
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@xxxxxxxxxxxxxx>
Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
LKML-Reference: <4B1DC4FB.5030407@xxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
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 a6c41cc..886268e 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,
};
--
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