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>

1 files changed, 14 insertions, 25 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 03c7fd55c5f9..12b49caedf82 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1361,10 +1361,11 @@ int trace_array_vprintk(struct trace_array *tr,
         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 @@ int trace_array_vprintk(struct trace_array *tr,
         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 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
         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 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
         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 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
                 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;