summaryrefslogtreecommitdiff
path: root/kernel/trace/ftrace.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c45
1 files changed, 26 insertions, 19 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8f4227d4cd39..2ae98f8bce81 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -32,6 +32,7 @@
#include <linux/list.h>
#include <linux/hash.h>
#include <linux/rcupdate.h>
+#include <linux/kprobes.h>
#include <trace/events/sched.h>
@@ -608,8 +609,7 @@ static int function_stat_show(struct seq_file *m, void *v)
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- avg = rec->time;
- do_div(avg, rec->counter);
+ avg = div64_ul(rec->time, rec->counter);
if (tracing_thresh && (avg < tracing_thresh))
goto out;
#endif
@@ -635,7 +635,8 @@ static int function_stat_show(struct seq_file *m, void *v)
* Divide only 1000 for ns^2 -> us^2 conversion.
* trace_print_graph_duration will divide 1000 again.
*/
- do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
+ stddev = div64_ul(stddev,
+ rec->counter * (rec->counter - 1) * 1000);
}
trace_seq_init(&s);
@@ -1630,6 +1631,11 @@ static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
return keep_regs;
}
+static struct ftrace_ops *
+ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
+static struct ftrace_ops *
+ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
+
static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
int filter_hash,
bool inc)
@@ -1758,15 +1764,17 @@ static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
}
/*
- * If the rec had TRAMP enabled, then it needs to
- * be cleared. As TRAMP can only be enabled iff
- * there is only a single ops attached to it.
- * In otherwords, always disable it on decrementing.
- * In the future, we may set it if rec count is
- * decremented to one, and the ops that is left
- * has a trampoline.
+ * The TRAMP needs to be set only if rec count
+ * is decremented to one, and the ops that is
+ * left has a trampoline. As TRAMP can only be
+ * enabled if there is only a single ops attached
+ * to it.
*/
- rec->flags &= ~FTRACE_FL_TRAMP;
+ if (ftrace_rec_count(rec) == 1 &&
+ ftrace_find_tramp_ops_any(rec))
+ rec->flags |= FTRACE_FL_TRAMP;
+ else
+ rec->flags &= ~FTRACE_FL_TRAMP;
/*
* flags will be cleared in ftrace_check_record()
@@ -1959,11 +1967,6 @@ static void print_ip_ins(const char *fmt, const unsigned char *p)
printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
}
-static struct ftrace_ops *
-ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
-static struct ftrace_ops *
-ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
-
enum ftrace_bug_type ftrace_bug_type;
const void *ftrace_expected;
@@ -5246,7 +5249,7 @@ void ftrace_reset_array_ops(struct trace_array *tr)
tr->ops->func = ftrace_stub;
}
-static inline void
+static nokprobe_inline void
__ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ignored, struct pt_regs *regs)
{
@@ -5309,11 +5312,13 @@ static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
{
__ftrace_ops_list_func(ip, parent_ip, NULL, regs);
}
+NOKPROBE_SYMBOL(ftrace_ops_list_func);
#else
static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
{
__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
}
+NOKPROBE_SYMBOL(ftrace_ops_no_ops);
#endif
/*
@@ -5343,6 +5348,7 @@ static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
preempt_enable_notrace();
trace_clear_recursion(bit);
}
+NOKPROBE_SYMBOL(ftrace_ops_assist_func);
/**
* ftrace_ops_get_func - get the function a trampoline should call
@@ -5449,9 +5455,10 @@ static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
struct trace_array *tr = m->private;
struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
- if (v == FTRACE_NO_PIDS)
+ if (v == FTRACE_NO_PIDS) {
+ (*pos)++;
return NULL;
-
+ }
return trace_pid_next(pid_list, v, pos);
}