1 files changed, 53 insertions, 25 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 85a5ed7..c82dfd9 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -129,7 +129,7 @@ static int tracing_set_tracer(const char *buf);
 static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
 static char *default_bootup_tracer;
 
-static int __init set_ftrace(char *str)
+static int __init set_cmdline_ftrace(char *str)
 {
 	strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
 	default_bootup_tracer = bootup_tracer_buf;
@@ -137,7 +137,7 @@ static int __init set_ftrace(char *str)
 	ring_buffer_expanded = 1;
 	return 1;
 }
-__setup("ftrace=", set_ftrace);
+__setup("ftrace=", set_cmdline_ftrace);
 
 static int __init set_ftrace_dump_on_oops(char *str)
 {
@@ -1363,9 +1363,6 @@ int trace_array_vprintk(struct trace_array *tr,
 	__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;
-
 	size = sizeof(*entry) + len + 1;
 	buffer = tr->buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
@@ -1373,10 +1370,10 @@ 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);
 
@@ -1393,7 +1390,7 @@ int trace_array_vprintk(struct trace_array *tr,
 
 int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 {
-	return trace_array_printk(&global_trace, ip, fmt, args);
+	return trace_array_vprintk(&global_trace, ip, fmt, args);
 }
 EXPORT_SYMBOL_GPL(trace_vprintk);
 
@@ -1515,6 +1512,8 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos)
 	int i = (int)*pos;
 	void *ent;
 
+	WARN_ON_ONCE(iter->leftover);
+
 	(*pos)++;
 
 	/* can't go backwards */
@@ -1613,8 +1612,16 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 			;
 
 	} else {
-		l = *pos - 1;
-		p = s_next(m, p, &l);
+		/*
+		 * If we overflowed the seq_file before, then we want
+		 * to just reuse the trace_seq buffer again.
+		 */
+		if (iter->leftover)
+			p = iter;
+		else {
+			l = *pos - 1;
+			p = s_next(m, p, &l);
+		}
 	}
 
 	trace_event_read_lock();
@@ -1922,6 +1929,7 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
 static int s_show(struct seq_file *m, void *v)
 {
 	struct trace_iterator *iter = v;
+	int ret;
 
 	if (iter->ent == NULL) {
 		if (iter->tr) {
@@ -1941,9 +1949,27 @@ static int s_show(struct seq_file *m, void *v)
 			if (!(trace_flags & TRACE_ITER_VERBOSE))
 				print_func_help_header(m);
 		}
+	} else if (iter->leftover) {
+		/*
+		 * If we filled the seq_file buffer earlier, we
+		 * want to just show it now.
+		 */
+		ret = trace_print_seq(m, &iter->seq);
+
+		/* ret should this time be zero, but you never know */
+		iter->leftover = ret;
+
 	} else {
 		print_trace_line(iter);
-		trace_print_seq(m, &iter->seq);
+		ret = trace_print_seq(m, &iter->seq);
+		/*
+		 * If we overflow the seq_file buffer, then it will
+		 * ask us for this data again at start up.
+		 * Use that instead.
+		 *  ret is 0 if seq_file write succeeded.
+		 *        -1 otherwise.
+		 */
+		iter->leftover = ret;
 	}
 
 	return 0;
@@ -2440,7 +2466,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 			return ret;
 	}
 
-	filp->f_pos += cnt;
+	*ppos += cnt;
 
 	return cnt;
 }
@@ -2582,7 +2608,7 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
 	}
 	mutex_unlock(&trace_types_lock);
 
-	filp->f_pos += cnt;
+	*ppos += cnt;
 
 	return cnt;
 }
@@ -2764,7 +2790,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 	if (err)
 		return err;
 
-	filp->f_pos += ret;
+	*ppos += ret;
 
 	return ret;
 }
@@ -2897,6 +2923,10 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
 	else
 		cpumask_clear_cpu(iter->cpu_file, tracing_reader_cpumask);
 
+
+	if (iter->trace->pipe_close)
+		iter->trace->pipe_close(iter);
+
 	mutex_unlock(&trace_types_lock);
 
 	free_cpumask_var(iter->started);
@@ -3299,7 +3329,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 		}
 	}
 
-	filp->f_pos += cnt;
+	*ppos += cnt;
 
 	/* If check pages failed, return ENOMEM */
 	if (tracing_disabled)
@@ -3334,7 +3364,6 @@ 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 +3371,7 @@ 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 +3379,13 @@ 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 = mark_printk("%s", buf);
 	kfree(buf);
 	*fpos += cnt;
 
@@ -3730,7 +3758,7 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 
 	s = kmalloc(sizeof(*s), GFP_KERNEL);
 	if (!s)
-		return ENOMEM;
+		return -ENOMEM;
 
 	trace_seq_init(s);