summary refs log tree commit diff
path: root/kernel/trace
diff options
context:
space:
mode:
authorFrederic Weisbecker <fweisbec@gmail.com>2008-10-04 22:04:44 +0200
committerIngo Molnar <mingo@elte.hu>2008-10-14 10:39:22 +0200
commitc2931e05ec5965597cbfb79ad332d4a29aeceb23 (patch)
treee1825834156ab83e7c5ed1bbd33c958e5da78b39 /kernel/trace
parent3ea2e6d71aafe35b8aaf89ed711a283815acfae6 (diff)
downloadlinux-c2931e05ec5965597cbfb79ad332d4a29aeceb23.tar.gz
ftrace: return an error when setting a nonexistent tracer
When one try to set a nonexistent tracer, no error is returned
as if the name of the tracer was correct.
We should return -EINVAL.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index caa4051ce778..78d56614c95b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2381,9 +2381,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 	struct tracer *t;
 	char buf[max_tracer_type_len+1];
 	int i;
+	size_t ret;
 
 	if (cnt > max_tracer_type_len)
 		cnt = max_tracer_type_len;
+	ret = cnt;
 
 	if (copy_from_user(&buf, ubuf, cnt))
 		return -EFAULT;
@@ -2399,7 +2401,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 		if (strcmp(t->name, buf) == 0)
 			break;
 	}
-	if (!t || t == current_trace)
+	if (!t) {
+		ret = -EINVAL;
+		goto out;
+	}
+	if (t == current_trace)
 		goto out;
 
 	if (current_trace && current_trace->reset)
@@ -2412,9 +2418,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
  out:
 	mutex_unlock(&trace_types_lock);
 
-	filp->f_pos += cnt;
+	if (ret == cnt)
+		filp->f_pos += cnt;
 
-	return cnt;
+	return ret;
 }
 
 static ssize_t