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Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ftrace.c32
-rw-r--r--kernel/trace/ring_buffer.c15
-rw-r--r--kernel/trace/trace.c5
-rw-r--r--kernel/trace/trace_irqsoff.c1
-rw-r--r--kernel/trace/trace_sched_wakeup.c1
5 files changed, 46 insertions, 8 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2f32969c09d..9a236ffe2aa 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -17,6 +17,7 @@
#include <linux/clocksource.h>
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
+#include <linux/suspend.h>
#include <linux/debugfs.h>
#include <linux/hardirq.h>
#include <linux/kthread.h>
@@ -1736,9 +1737,12 @@ static void clear_ftrace_pid(struct pid *pid)
{
struct task_struct *p;
+ rcu_read_lock();
do_each_pid_task(pid, PIDTYPE_PID, p) {
clear_tsk_trace_trace(p);
} while_each_pid_task(pid, PIDTYPE_PID, p);
+ rcu_read_unlock();
+
put_pid(pid);
}
@@ -1746,9 +1750,11 @@ static void set_ftrace_pid(struct pid *pid)
{
struct task_struct *p;
+ rcu_read_lock();
do_each_pid_task(pid, PIDTYPE_PID, p) {
set_tsk_trace_trace(p);
} while_each_pid_task(pid, PIDTYPE_PID, p);
+ rcu_read_unlock();
}
static void clear_ftrace_pid_task(struct pid **pid)
@@ -1965,6 +1971,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static atomic_t ftrace_graph_active;
+static struct notifier_block ftrace_suspend_notifier;
int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
{
@@ -2043,6 +2050,27 @@ static int start_graph_tracing(void)
return ret;
}
+/*
+ * Hibernation protection.
+ * The state of the current task is too much unstable during
+ * suspend/restore to disk. We want to protect against that.
+ */
+static int
+ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state,
+ void *unused)
+{
+ switch (state) {
+ case PM_HIBERNATION_PREPARE:
+ pause_graph_tracing();
+ break;
+
+ case PM_POST_HIBERNATION:
+ unpause_graph_tracing();
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
int register_ftrace_graph(trace_func_graph_ret_t retfunc,
trace_func_graph_ent_t entryfunc)
{
@@ -2050,6 +2078,9 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
mutex_lock(&ftrace_sysctl_lock);
+ ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
+ register_pm_notifier(&ftrace_suspend_notifier);
+
atomic_inc(&ftrace_graph_active);
ret = start_graph_tracing();
if (ret) {
@@ -2075,6 +2106,7 @@ void unregister_ftrace_graph(void)
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
ftrace_graph_entry = ftrace_graph_entry_stub;
ftrace_shutdown(FTRACE_STOP_FUNC_RET);
+ unregister_pm_notifier(&ftrace_suspend_notifier);
mutex_unlock(&ftrace_sysctl_lock);
}
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 8b0daf0662e..bd38c5cfd8a 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -246,7 +246,7 @@ static inline int test_time_stamp(u64 delta)
return 0;
}
-#define BUF_PAGE_SIZE (PAGE_SIZE - sizeof(struct buffer_data_page))
+#define BUF_PAGE_SIZE (PAGE_SIZE - offsetof(struct buffer_data_page, data))
/*
* head_page == tail_page && head == tail then buffer is empty.
@@ -1025,12 +1025,8 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
}
if (next_page == head_page) {
- if (!(buffer->flags & RB_FL_OVERWRITE)) {
- /* reset write */
- if (tail <= BUF_PAGE_SIZE)
- local_set(&tail_page->write, tail);
+ if (!(buffer->flags & RB_FL_OVERWRITE))
goto out_unlock;
- }
/* tail_page has not moved yet? */
if (tail_page == cpu_buffer->tail_page) {
@@ -1105,6 +1101,10 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
return event;
out_unlock:
+ /* reset write */
+ if (tail <= BUF_PAGE_SIZE)
+ local_set(&tail_page->write, tail);
+
__raw_spin_unlock(&cpu_buffer->lock);
local_irq_restore(flags);
return NULL;
@@ -2174,6 +2174,9 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
cpu_buffer->overrun = 0;
cpu_buffer->entries = 0;
+
+ cpu_buffer->write_stamp = 0;
+ cpu_buffer->read_stamp = 0;
}
/**
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c580233add9..17bb88d86ac 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -40,7 +40,7 @@
#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE)
-unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
+unsigned long __read_mostly tracing_max_latency;
unsigned long __read_mostly tracing_thresh;
/*
@@ -3736,7 +3736,7 @@ static struct notifier_block trace_die_notifier = {
* it if we decide to change what log level the ftrace dump
* should be at.
*/
-#define KERN_TRACE KERN_INFO
+#define KERN_TRACE KERN_EMERG
static void
trace_printk_seq(struct trace_seq *s)
@@ -3770,6 +3770,7 @@ void ftrace_dump(void)
dump_ran = 1;
/* No turning back! */
+ tracing_off();
ftrace_kill();
for_each_tracing_cpu(cpu) {
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 7c2e326bbc8..62a78d94353 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -380,6 +380,7 @@ static void stop_irqsoff_tracer(struct trace_array *tr)
static void __irqsoff_tracer_init(struct trace_array *tr)
{
+ tracing_max_latency = 0;
irqsoff_trace = tr;
/* make sure that the tracer is visible */
smp_wmb();
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 43586b689e3..42ae1e77b6b 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -333,6 +333,7 @@ static void stop_wakeup_tracer(struct trace_array *tr)
static int wakeup_tracer_init(struct trace_array *tr)
{
+ tracing_max_latency = 0;
wakeup_trace = tr;
start_wakeup_tracer(tr);
return 0;