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-rw-r--r--include/linux/ftrace.h46
-rw-r--r--include/linux/sched.h4
-rw-r--r--kernel/trace/ftrace.c227
-rw-r--r--kernel/trace/trace.c8
-rw-r--r--kernel/trace/trace.h30
5 files changed, 314 insertions, 1 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 469ceb3..b295d31 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -7,6 +7,7 @@
#include <linux/init.h>
#include <linux/types.h>
#include <linux/kallsyms.h>
+#include <linux/bitops.h>
#ifdef CONFIG_FUNCTION_TRACER
@@ -391,4 +392,49 @@ static inline void ftrace_graph_init_task(struct task_struct *t) { }
static inline void ftrace_graph_exit_task(struct task_struct *t) { }
#endif
+#ifdef CONFIG_TRACING
+#include <linux/sched.h>
+
+/* flags for current->trace */
+enum {
+ TSK_TRACE_FL_TRACE_BIT = 0,
+ TSK_TRACE_FL_GRAPH_BIT = 1,
+};
+enum {
+ TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
+ TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
+};
+
+static inline void set_tsk_trace_trace(struct task_struct *tsk)
+{
+ set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
+}
+
+static inline void clear_tsk_trace_trace(struct task_struct *tsk)
+{
+ clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
+}
+
+static inline int test_tsk_trace_trace(struct task_struct *tsk)
+{
+ return tsk->trace & TSK_TRACE_FL_TRACE;
+}
+
+static inline void set_tsk_trace_graph(struct task_struct *tsk)
+{
+ set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
+}
+
+static inline void clear_tsk_trace_graph(struct task_struct *tsk)
+{
+ clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
+}
+
+static inline int test_tsk_trace_graph(struct task_struct *tsk)
+{
+ return tsk->trace & TSK_TRACE_FL_GRAPH;
+}
+
+#endif /* CONFIG_TRACING */
+
#endif /* _LINUX_FTRACE_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2d0a93c..4c152e0 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1380,6 +1380,10 @@ struct task_struct {
*/
atomic_t trace_overrun;
#endif
+#ifdef CONFIG_TRACING
+ /* state flags for use by tracers */
+ unsigned long trace;
+#endif
};
/*
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 65b9e86..b17a303 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1320,6 +1320,224 @@ static struct file_operations ftrace_notrace_fops = {
.release = ftrace_notrace_release,
};
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static DEFINE_MUTEX(graph_lock);
+
+int ftrace_graph_count;
+unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
+
+static void *
+g_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ unsigned long *array = m->private;
+ int index = *pos;
+
+ (*pos)++;
+
+ if (index >= ftrace_graph_count)
+ return NULL;
+
+ return &array[index];
+}
+
+static void *g_start(struct seq_file *m, loff_t *pos)
+{
+ void *p = NULL;
+
+ mutex_lock(&graph_lock);
+
+ p = g_next(m, p, pos);
+
+ return p;
+}
+
+static void g_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&graph_lock);
+}
+
+static int g_show(struct seq_file *m, void *v)
+{
+ unsigned long *ptr = v;
+ char str[KSYM_SYMBOL_LEN];
+
+ if (!ptr)
+ return 0;
+
+ kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
+
+ seq_printf(m, "%s\n", str);
+
+ return 0;
+}
+
+static struct seq_operations ftrace_graph_seq_ops = {
+ .start = g_start,
+ .next = g_next,
+ .stop = g_stop,
+ .show = g_show,
+};
+
+static int
+ftrace_graph_open(struct inode *inode, struct file *file)
+{
+ int ret = 0;
+
+ if (unlikely(ftrace_disabled))
+ return -ENODEV;
+
+ mutex_lock(&graph_lock);
+ if ((file->f_mode & FMODE_WRITE) &&
+ !(file->f_flags & O_APPEND)) {
+ ftrace_graph_count = 0;
+ memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
+ }
+
+ if (file->f_mode & FMODE_READ) {
+ ret = seq_open(file, &ftrace_graph_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = ftrace_graph_funcs;
+ }
+ } else
+ file->private_data = ftrace_graph_funcs;
+ mutex_unlock(&graph_lock);
+
+ return ret;
+}
+
+static ssize_t
+ftrace_graph_read(struct file *file, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ if (file->f_mode & FMODE_READ)
+ return seq_read(file, ubuf, cnt, ppos);
+ else
+ return -EPERM;
+}
+
+static int
+ftrace_set_func(unsigned long *array, int idx, char *buffer)
+{
+ char str[KSYM_SYMBOL_LEN];
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ int found = 0;
+ int i;
+
+ if (ftrace_disabled)
+ return -ENODEV;
+
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+
+ for (pg = ftrace_pages_start; pg; pg = pg->next) {
+ for (i = 0; i < pg->index; i++) {
+ rec = &pg->records[i];
+
+ if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
+ continue;
+
+ kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+ if (strcmp(str, buffer) == 0) {
+ found = 1;
+ array[idx] = rec->ip;
+ break;
+ }
+ }
+ }
+ spin_unlock(&ftrace_lock);
+
+ return found ? 0 : -EINVAL;
+}
+
+static ssize_t
+ftrace_graph_write(struct file *file, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ unsigned char buffer[FTRACE_BUFF_MAX+1];
+ unsigned long *array;
+ size_t read = 0;
+ ssize_t ret;
+ int index = 0;
+ char ch;
+
+ if (!cnt || cnt < 0)
+ return 0;
+
+ mutex_lock(&graph_lock);
+
+ if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ if (file->f_mode & FMODE_READ) {
+ struct seq_file *m = file->private_data;
+ array = m->private;
+ } else
+ array = file->private_data;
+
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+
+ /* skip white space */
+ while (cnt && isspace(ch)) {
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+ }
+
+ if (isspace(ch)) {
+ *ppos += read;
+ ret = read;
+ goto out;
+ }
+
+ while (cnt && !isspace(ch)) {
+ if (index < FTRACE_BUFF_MAX)
+ buffer[index++] = ch;
+ else {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = get_user(ch, ubuf++);
+ if (ret)
+ goto out;
+ read++;
+ cnt--;
+ }
+ buffer[index] = 0;
+
+ /* we allow only one at a time */
+ ret = ftrace_set_func(array, ftrace_graph_count, buffer);
+ if (ret)
+ goto out;
+
+ ftrace_graph_count++;
+
+ file->f_pos += read;
+
+ ret = read;
+ out:
+ mutex_unlock(&graph_lock);
+
+ return ret;
+}
+
+static const struct file_operations ftrace_graph_fops = {
+ .open = ftrace_graph_open,
+ .read = ftrace_graph_read,
+ .write = ftrace_graph_write,
+};
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
{
struct dentry *entry;
@@ -1347,6 +1565,15 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
pr_warning("Could not create debugfs "
"'set_ftrace_notrace' entry\n");
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ entry = debugfs_create_file("set_graph_function", 0444, d_tracer,
+ NULL,
+ &ftrace_graph_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'set_graph_function' entry\n");
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
return 0;
}
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8b6409a..710b39a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1209,6 +1209,9 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
int cpu;
int pc;
+ if (!ftrace_graph_addr(trace->func))
+ return 0;
+
local_irq_save(flags);
cpu = raw_smp_processor_id();
data = tr->data[cpu];
@@ -1217,6 +1220,9 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
pc = preempt_count();
__trace_graph_entry(tr, data, trace, flags, pc);
}
+ /* Only do the atomic if it is not already set */
+ if (!test_tsk_trace_graph(current))
+ set_tsk_trace_graph(current);
atomic_dec(&data->disabled);
local_irq_restore(flags);
@@ -1240,6 +1246,8 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
pc = preempt_count();
__trace_graph_return(tr, data, trace, flags, pc);
}
+ if (!trace->depth)
+ clear_tsk_trace_graph(current);
atomic_dec(&data->disabled);
local_irq_restore(flags);
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 0565ae9..41f026b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -505,13 +505,41 @@ extern unsigned long trace_flags;
/* Standard output formatting function used for function return traces */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern enum print_line_t print_graph_function(struct trace_iterator *iter);
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+/* TODO: make this variable */
+#define FTRACE_GRAPH_MAX_FUNCS 32
+extern int ftrace_graph_count;
+extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
+
+static inline int ftrace_graph_addr(unsigned long addr)
+{
+ int i;
+
+ if (!ftrace_graph_count || test_tsk_trace_graph(current))
+ return 1;
+
+ for (i = 0; i < ftrace_graph_count; i++) {
+ if (addr == ftrace_graph_funcs[i])
+ return 1;
+ }
+
+ return 0;
+}
#else
+static inline int ftrace_trace_addr(unsigned long addr)
+{
+ return 1
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#else /* CONFIG_FUNCTION_GRAPH_TRACER */
static inline enum print_line_t
print_graph_function(struct trace_iterator *iter)
{
return TRACE_TYPE_UNHANDLED;
}
-#endif
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
/*
* trace_iterator_flags is an enumeration that defines bit
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