1 files changed, 77 insertions, 105 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 31118ae..06ba267 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -313,7 +313,6 @@ static const char *trace_options[] = {
 	"bin",
 	"block",
 	"stacktrace",
-	"sched-tree",
 	"trace_printk",
 	"ftrace_preempt",
 	"branch",
@@ -1151,6 +1150,22 @@ void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
 	__ftrace_trace_stack(tr->buffer, flags, skip, pc);
 }
 
+/**
+ * trace_dump_stack - record a stack back trace in the trace buffer
+ */
+void trace_dump_stack(void)
+{
+	unsigned long flags;
+
+	if (tracing_disabled || tracing_selftest_running)
+		return;
+
+	local_save_flags(flags);
+
+	/* skipping 3 traces, seems to get us at the caller of this function */
+	__ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count());
+}
+
 void
 ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 {
@@ -2316,67 +2331,49 @@ static const struct file_operations tracing_cpumask_fops = {
 	.write		= tracing_cpumask_write,
 };
 
-static ssize_t
-tracing_trace_options_read(struct file *filp, char __user *ubuf,
-		       size_t cnt, loff_t *ppos)
+static int tracing_trace_options_show(struct seq_file *m, void *v)
 {
 	struct tracer_opt *trace_opts;
 	u32 tracer_flags;
-	int len = 0;
-	char *buf;
-	int r = 0;
 	int i;
 
-
-	/* calculate max size */
-	for (i = 0; trace_options[i]; i++) {
-		len += strlen(trace_options[i]);
-		len += 3; /* "no" and newline */
-	}
-
 	mutex_lock(&trace_types_lock);
 	tracer_flags = current_trace->flags->val;
 	trace_opts = current_trace->flags->opts;
 
-	/*
-	 * Increase the size with names of options specific
-	 * of the current tracer.
-	 */
-	for (i = 0; trace_opts[i].name; i++) {
-		len += strlen(trace_opts[i].name);
-		len += 3; /* "no" and newline */
-	}
-
-	/* +1 for \0 */
-	buf = kmalloc(len + 1, GFP_KERNEL);
-	if (!buf) {
-		mutex_unlock(&trace_types_lock);
-		return -ENOMEM;
-	}
-
 	for (i = 0; trace_options[i]; i++) {
 		if (trace_flags & (1 << i))
-			r += sprintf(buf + r, "%s\n", trace_options[i]);
+			seq_printf(m, "%s\n", trace_options[i]);
 		else
-			r += sprintf(buf + r, "no%s\n", trace_options[i]);
+			seq_printf(m, "no%s\n", trace_options[i]);
 	}
 
 	for (i = 0; trace_opts[i].name; i++) {
 		if (tracer_flags & trace_opts[i].bit)
-			r += sprintf(buf + r, "%s\n",
-				trace_opts[i].name);
+			seq_printf(m, "%s\n", trace_opts[i].name);
 		else
-			r += sprintf(buf + r, "no%s\n",
-				trace_opts[i].name);
+			seq_printf(m, "no%s\n", trace_opts[i].name);
 	}
 	mutex_unlock(&trace_types_lock);
 
-	WARN_ON(r >= len + 1);
+	return 0;
+}
 
-	r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+static int __set_tracer_option(struct tracer *trace,
+			       struct tracer_flags *tracer_flags,
+			       struct tracer_opt *opts, int neg)
+{
+	int ret;
 
-	kfree(buf);
-	return r;
+	ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
+	if (ret)
+		return ret;
+
+	if (neg)
+		tracer_flags->val &= ~opts->bit;
+	else
+		tracer_flags->val |= opts->bit;
+	return 0;
 }
 
 /* Try to assign a tracer specific option */
@@ -2384,33 +2381,17 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
 {
 	struct tracer_flags *tracer_flags = trace->flags;
 	struct tracer_opt *opts = NULL;
-	int ret = 0, i = 0;
-	int len;
+	int i;
 
 	for (i = 0; tracer_flags->opts[i].name; i++) {
 		opts = &tracer_flags->opts[i];
-		len = strlen(opts->name);
 
-		if (strncmp(cmp, opts->name, len) == 0) {
-			ret = trace->set_flag(tracer_flags->val,
-				opts->bit, !neg);
-			break;
-		}
+		if (strcmp(cmp, opts->name) == 0)
+			return __set_tracer_option(trace, trace->flags,
+						   opts, neg);
 	}
-	/* Not found */
-	if (!tracer_flags->opts[i].name)
-		return -EINVAL;
-
-	/* Refused to handle */
-	if (ret)
-		return ret;
-
-	if (neg)
-		tracer_flags->val &= ~opts->bit;
-	else
-		tracer_flags->val |= opts->bit;
 
-	return 0;
+	return -EINVAL;
 }
 
 static void set_tracer_flags(unsigned int mask, int enabled)
@@ -2430,7 +2411,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 			size_t cnt, loff_t *ppos)
 {
 	char buf[64];
-	char *cmp = buf;
+	char *cmp;
 	int neg = 0;
 	int ret;
 	int i;
@@ -2442,16 +2423,15 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 		return -EFAULT;
 
 	buf[cnt] = 0;
+	cmp = strstrip(buf);
 
-	if (strncmp(buf, "no", 2) == 0) {
+	if (strncmp(cmp, "no", 2) == 0) {
 		neg = 1;
 		cmp += 2;
 	}
 
 	for (i = 0; trace_options[i]; i++) {
-		int len = strlen(trace_options[i]);
-
-		if (strncmp(cmp, trace_options[i], len) == 0) {
+		if (strcmp(cmp, trace_options[i]) == 0) {
 			set_tracer_flags(1 << i, !neg);
 			break;
 		}
@@ -2471,9 +2451,18 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 	return cnt;
 }
 
+static int tracing_trace_options_open(struct inode *inode, struct file *file)
+{
+	if (tracing_disabled)
+		return -ENODEV;
+	return single_open(file, tracing_trace_options_show, NULL);
+}
+
 static const struct file_operations tracing_iter_fops = {
-	.open		= tracing_open_generic,
-	.read		= tracing_trace_options_read,
+	.open		= tracing_trace_options_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
 	.write		= tracing_trace_options_write,
 };
 
@@ -3392,21 +3381,18 @@ 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,
@@ -3448,6 +3434,13 @@ 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,
@@ -3486,8 +3479,10 @@ 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,
 };
 
@@ -3948,39 +3943,16 @@ trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
 	if (ret < 0)
 		return ret;
 
-	ret = 0;
-	switch (val) {
-	case 0:
-		/* do nothing if already cleared */
-		if (!(topt->flags->val & topt->opt->bit))
-			break;
-
-		mutex_lock(&trace_types_lock);
-		if (current_trace->set_flag)
-			ret = current_trace->set_flag(topt->flags->val,
-						      topt->opt->bit, 0);
-		mutex_unlock(&trace_types_lock);
-		if (ret)
-			return ret;
-		topt->flags->val &= ~topt->opt->bit;
-		break;
-	case 1:
-		/* do nothing if already set */
-		if (topt->flags->val & topt->opt->bit)
-			break;
+	if (val != 0 && val != 1)
+		return -EINVAL;
 
+	if (!!(topt->flags->val & topt->opt->bit) != val) {
 		mutex_lock(&trace_types_lock);
-		if (current_trace->set_flag)
-			ret = current_trace->set_flag(topt->flags->val,
-						      topt->opt->bit, 1);
+		ret = __set_tracer_option(current_trace, topt->flags,
+					  topt->opt, val);
 		mutex_unlock(&trace_types_lock);
 		if (ret)
 			return ret;
-		topt->flags->val |= topt->opt->bit;
-		break;
-
-	default:
-		return -EINVAL;
 	}
 
 	*ppos += cnt;