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Commit 56f410cf authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing fixes from Steven Rostedt:

 - Fix a bug caused by not cleaning up the new instance unique triggers
   when deleting an instance. It also creates a selftest that triggers
   that bug.

 - Fix the delayed optimization happening after kprobes boot up self
   tests being removed by freeing of init memory.

 - Comment kprobes on why the delay optimization is not a problem for
   removal of modules, to keep other developers from searching that
   riddle.

 - Fix another case of rcu not watching in stack trace tracing.

* tag 'trace-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Make sure RCU is watching before calling a stack trace
  kprobes: Document how optimized kprobes are removed from module unload
  selftests/ftrace: Add test to remove instance with active event triggers
  selftests/ftrace: Fix bashisms
  ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stub
  ftrace/instances: Clear function triggers when removing instances
  ftrace: Simplify glob handling in unregister_ftrace_function_probe_func()
  tracing/kprobes: Enforce kprobes teardown after testing
  tracing: Move postpone selftests to core from early_initcall
parents 894e2164 a33d7d94

include/linux/kprobes.h

+3 −0
Original line number Diff line number Diff line
@@ -349,6 +349,9 @@ extern int proc_kprobes_optimization_handler(struct ctl_table *table, 
					     int write, void __user *buffer,

					     size_t *length, loff_t *ppos);

#endif

extern void wait_for_kprobe_optimizer(void);

#else

static inline void wait_for_kprobe_optimizer(void) { }

#endif /* CONFIG_OPTPROBES */

#ifdef CONFIG_KPROBES_ON_FTRACE

extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,

kernel/kprobes.c

+7 −1
Original line number Diff line number Diff line
@@ -595,7 +595,7 @@ static void kprobe_optimizer(struct work_struct *work) 
}



/* Wait for completing optimization and unoptimization */

static void wait_for_kprobe_optimizer(void)

void wait_for_kprobe_optimizer(void)

{

	mutex_lock(&kprobe_mutex);
@@ -2183,6 +2183,12 @@ static int kprobes_module_callback(struct notifier_block *nb, 
				 * The vaddr this probe is installed will soon

				 * be vfreed buy not synced to disk. Hence,

				 * disarming the breakpoint isn't needed.

				 *

				 * Note, this will also move any optimized probes

				 * that are pending to be removed from their

				 * corresponding lists to the freeing_list and

				 * will not be touched by the delayed

				 * kprobe_optimizer work handler.

				 */

				kill_kprobe(p);

			}

kernel/trace/ftrace.c

+10 −2
Original line number Diff line number Diff line
@@ -4144,9 +4144,9 @@ unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, 
	int i, ret = -ENODEV;

	int size;



	if (glob && (strcmp(glob, "*") == 0 || !strlen(glob)))

	if (!glob || !strlen(glob) || !strcmp(glob, "*"))

		func_g.search = NULL;

	else if (glob) {

	else {

		int not;



		func_g.type = filter_parse_regex(glob, strlen(glob),
@@ -4256,6 +4256,14 @@ unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr, 
	return ret;

}



void clear_ftrace_function_probes(struct trace_array *tr)

{

	struct ftrace_func_probe *probe, *n;



	list_for_each_entry_safe(probe, n, &tr->func_probes, list)

		unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);

}



static LIST_HEAD(ftrace_commands);

static DEFINE_MUTEX(ftrace_cmd_mutex);

kernel/trace/trace.c

+32 −2
Original line number Diff line number Diff line
@@ -1558,7 +1558,7 @@ static __init int init_trace_selftests(void) 


	return 0;

}

early_initcall(init_trace_selftests);

core_initcall(init_trace_selftests);

#else

static inline int run_tracer_selftest(struct tracer *type)

{
@@ -2568,7 +2568,36 @@ static inline void ftrace_trace_stack(struct trace_array *tr, 
void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,

		   int pc)

{

	__ftrace_trace_stack(tr->trace_buffer.buffer, flags, skip, pc, NULL);

	struct ring_buffer *buffer = tr->trace_buffer.buffer;



	if (rcu_is_watching()) {

		__ftrace_trace_stack(buffer, flags, skip, pc, NULL);

		return;

	}



	/*

	 * When an NMI triggers, RCU is enabled via rcu_nmi_enter(),

	 * but if the above rcu_is_watching() failed, then the NMI

	 * triggered someplace critical, and rcu_irq_enter() should

	 * not be called from NMI.

	 */

	if (unlikely(in_nmi()))

		return;



	/*

	 * It is possible that a function is being traced in a

	 * location that RCU is not watching. A call to

	 * rcu_irq_enter() will make sure that it is, but there's

	 * a few internal rcu functions that could be traced

	 * where that wont work either. In those cases, we just

	 * do nothing.

	 */

	if (unlikely(rcu_irq_enter_disabled()))

		return;



	rcu_irq_enter_irqson();

	__ftrace_trace_stack(buffer, flags, skip, pc, NULL);

	rcu_irq_exit_irqson();

}



/**
@@ -7550,6 +7579,7 @@ static int instance_rmdir(const char *name) 
	}



	tracing_set_nop(tr);

	clear_ftrace_function_probes(tr);

	event_trace_del_tracer(tr);

	ftrace_clear_pids(tr);

	ftrace_destroy_function_files(tr);

kernel/trace/trace.h

+5 −0
Original line number Diff line number Diff line
@@ -980,6 +980,7 @@ register_ftrace_function_probe(char *glob, struct trace_array *tr, 
extern int

unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,

				      struct ftrace_probe_ops *ops);

extern void clear_ftrace_function_probes(struct trace_array *tr);



int register_ftrace_command(struct ftrace_func_command *cmd);

int unregister_ftrace_command(struct ftrace_func_command *cmd);
@@ -998,6 +999,10 @@ static inline __init int unregister_ftrace_command(char *cmd_name) 
{

	return -EINVAL;

}

static inline void clear_ftrace_function_probes(struct trace_array *tr)

{

}



/*

 * The ops parameter passed in is usually undefined.

 * This must be a macro.