tracing: Fix trace_marker output
When a string was written to <debugfs>/tracing/trace_marker, some
strange characters appeared in the trace output instead of the
string, since a vprint function erroneously called a vararg print
function with a va_list argument. This patch fixes the problem and
simplifies the related code.
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
LKML-Reference: <4B01AE5D.1010801@osadl.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 03c7fd5..12b49ca 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1361,10 +1361,11 @@
pause_graph_tracing();
raw_local_irq_save(irq_flags);
__raw_spin_lock(&trace_buf_lock);
- len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
-
- len = min(len, TRACE_BUF_SIZE-1);
- trace_buf[len] = 0;
+ if (args == NULL) {
+ strncpy(trace_buf, fmt, TRACE_BUF_SIZE);
+ len = strlen(trace_buf);
+ } else
+ len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
size = sizeof(*entry) + len + 1;
buffer = tr->buffer;
@@ -1373,10 +1374,10 @@
if (!event)
goto out_unlock;
entry = ring_buffer_event_data(event);
- entry->ip = ip;
+ entry->ip = ip;
memcpy(&entry->buf, trace_buf, len);
- entry->buf[len] = 0;
+ entry->buf[len] = '\0';
if (!filter_check_discard(call, entry, buffer, event))
ring_buffer_unlock_commit(buffer, event);
@@ -3319,22 +3320,11 @@
return cnt;
}
-static int mark_printk(const char *fmt, ...)
-{
- int ret;
- va_list args;
- va_start(args, fmt);
- ret = trace_vprintk(0, fmt, args);
- va_end(args);
- return ret;
-}
-
static ssize_t
tracing_mark_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *fpos)
{
char *buf;
- char *end;
if (tracing_disabled)
return -EINVAL;
@@ -3342,7 +3332,7 @@
if (cnt > TRACE_BUF_SIZE)
cnt = TRACE_BUF_SIZE;
- buf = kmalloc(cnt + 1, GFP_KERNEL);
+ buf = kmalloc(cnt + 2, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
@@ -3350,14 +3340,13 @@
kfree(buf);
return -EFAULT;
}
+ if (buf[cnt-1] != '\n') {
+ buf[cnt] = '\n';
+ buf[cnt+1] = '\0';
+ } else
+ buf[cnt] = '\0';
- /* Cut from the first nil or newline. */
- buf[cnt] = '\0';
- end = strchr(buf, '\n');
- if (end)
- *end = '\0';
-
- cnt = mark_printk("%s\n", buf);
+ cnt = trace_vprintk(0, buf, NULL);
kfree(buf);
*fpos += cnt;