summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--kernel/trace/trace.c72
-rw-r--r--kernel/trace/trace.h1
-rw-r--r--kernel/trace/trace_nop.c3
3 files changed, 60 insertions, 16 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ee8da93..944cd02 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -119,7 +119,7 @@ enum ftrace_dump_mode ftrace_dump_on_oops;
/* When set, tracing will stop when a WARN*() is hit */
int __disable_trace_on_warning;
-static int tracing_set_tracer(const char *buf);
+static int tracing_set_tracer(struct trace_array *tr, const char *buf);
#define MAX_TRACER_SIZE 100
static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
@@ -1231,7 +1231,7 @@ int register_tracer(struct tracer *type)
printk(KERN_INFO "Starting tracer '%s'\n", type->name);
/* Do we want this tracer to start on bootup? */
- tracing_set_tracer(type->name);
+ tracing_set_tracer(&global_trace, type->name);
default_bootup_tracer = NULL;
/* disable other selftests, since this will break it. */
tracing_selftest_disabled = true;
@@ -3122,27 +3122,52 @@ static int tracing_open(struct inode *inode, struct file *file)
return ret;
}
+/*
+ * Some tracers are not suitable for instance buffers.
+ * A tracer is always available for the global array (toplevel)
+ * or if it explicitly states that it is.
+ */
+static bool
+trace_ok_for_array(struct tracer *t, struct trace_array *tr)
+{
+ return (tr->flags & TRACE_ARRAY_FL_GLOBAL) || t->allow_instances;
+}
+
+/* Find the next tracer that this trace array may use */
+static struct tracer *
+get_tracer_for_array(struct trace_array *tr, struct tracer *t)
+{
+ while (t && !trace_ok_for_array(t, tr))
+ t = t->next;
+
+ return t;
+}
+
static void *
t_next(struct seq_file *m, void *v, loff_t *pos)
{
+ struct trace_array *tr = m->private;
struct tracer *t = v;
(*pos)++;
if (t)
- t = t->next;
+ t = get_tracer_for_array(tr, t->next);
return t;
}
static void *t_start(struct seq_file *m, loff_t *pos)
{
+ struct trace_array *tr = m->private;
struct tracer *t;
loff_t l = 0;
mutex_lock(&trace_types_lock);
- for (t = trace_types; t && l < *pos; t = t_next(m, t, &l))
- ;
+
+ t = get_tracer_for_array(tr, trace_types);
+ for (; t && l < *pos; t = t_next(m, t, &l))
+ ;
return t;
}
@@ -3177,10 +3202,21 @@ static const struct seq_operations show_traces_seq_ops = {
static int show_traces_open(struct inode *inode, struct file *file)
{
+ struct trace_array *tr = inode->i_private;
+ struct seq_file *m;
+ int ret;
+
if (tracing_disabled)
return -ENODEV;
- return seq_open(file, &show_traces_seq_ops);
+ ret = seq_open(file, &show_traces_seq_ops);
+ if (ret)
+ return ret;
+
+ m = file->private_data;
+ m->private = tr;
+
+ return 0;
}
static ssize_t
@@ -3871,10 +3907,9 @@ create_trace_option_files(struct trace_array *tr, struct tracer *tracer);
static void
destroy_trace_option_files(struct trace_option_dentry *topts);
-static int tracing_set_tracer(const char *buf)
+static int tracing_set_tracer(struct trace_array *tr, const char *buf)
{
static struct trace_option_dentry *topts;
- struct trace_array *tr = &global_trace;
struct tracer *t;
#ifdef CONFIG_TRACER_MAX_TRACE
bool had_max_tr;
@@ -3902,6 +3937,12 @@ static int tracing_set_tracer(const char *buf)
if (t == tr->current_trace)
goto out;
+ /* Some tracers are only allowed for the top level buffer */
+ if (!trace_ok_for_array(t, tr)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
trace_branch_disable();
tr->current_trace->enabled = false;
@@ -3958,6 +3999,7 @@ static ssize_t
tracing_set_trace_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
+ struct trace_array *tr = filp->private_data;
char buf[MAX_TRACER_SIZE+1];
int i;
size_t ret;
@@ -3977,7 +4019,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
buf[i] = 0;
- err = tracing_set_tracer(buf);
+ err = tracing_set_tracer(tr, buf);
if (err)
return err;
@@ -6193,6 +6235,12 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer)
{
int cpu;
+ trace_create_file("available_tracers", 0444, d_tracer,
+ tr, &show_traces_fops);
+
+ trace_create_file("current_tracer", 0644, d_tracer,
+ tr, &set_tracer_fops);
+
trace_create_file("tracing_cpumask", 0644, d_tracer,
tr, &tracing_cpumask_fops);
@@ -6245,12 +6293,6 @@ static __init int tracer_init_debugfs(void)
init_tracer_debugfs(&global_trace, d_tracer);
- trace_create_file("available_tracers", 0444, d_tracer,
- &global_trace, &show_traces_fops);
-
- trace_create_file("current_tracer", 0644, d_tracer,
- &global_trace, &set_tracer_fops);
-
#ifdef CONFIG_TRACER_MAX_TRACE
trace_create_file("tracing_max_latency", 0644, d_tracer,
&tracing_max_latency, &tracing_max_lat_fops);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 36e4473..ea51bb2 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -364,6 +364,7 @@ struct tracer {
struct tracer_flags *flags;
bool print_max;
bool enabled;
+ bool allow_instances;
#ifdef CONFIG_TRACER_MAX_TRACE
bool use_max_tr;
#endif
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index f398409..69a5cc9 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -96,6 +96,7 @@ struct tracer nop_trace __read_mostly =
.selftest = trace_selftest_startup_nop,
#endif
.flags = &nop_flags,
- .set_flag = nop_set_flag
+ .set_flag = nop_set_flag,
+ .allow_instances = true,
};
OpenPOWER on IntegriCloud