Commit 8ae516aa authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-fixes-v3.13-rc1' of... 

Merge tag 'trace-fixes-v3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This includes two fixes.

  1) is a bug fix that happens when root does the following:

     echo function_graph > current_tracer
     modprobe foo
     echo nop > current_tracer

   This causes the ftrace internal accounting to get screwed up and
   crashes ftrace, preventing the user from using the function tracer
   after that.

  2) if a TRACE_EVENT has a string field, and NULL is given for it.

   The internal trace event code does a strlen() and strcpy() on the
   source of field.  If it is NULL it causes the system to oops.

   This bug has been there since 2.6.31, but no TRACE_EVENT ever passed
   in a NULL to the string field, until now"

* tag 'trace-fixes-v3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix function graph with loading of modules
  tracing: Allow events to have NULL strings
parents 4f9e5df2 8a56d776

include/trace/ftrace.h

+3 −2
Original line number Diff line number Diff line
@@ -372,7 +372,8 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call) \ 
	__data_size += (len) * sizeof(type);



#undef __string

#define __string(item, src) __dynamic_array(char, item, strlen(src) + 1)

#define __string(item, src) __dynamic_array(char, item,			\

		    strlen((src) ? (const char *)(src) : "(null)") + 1)



#undef DECLARE_EVENT_CLASS

#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
@@ -501,7 +502,7 @@ static inline notrace int ftrace_get_offsets_##call( \ 


#undef __assign_str

#define __assign_str(dst, src)						\

	strcpy(__get_str(dst), src);

	strcpy(__get_str(dst), (src) ? (const char *)(src) : "(null)");



#undef TP_fast_assign

#define TP_fast_assign(args...) args

kernel/trace/ftrace.c

+35 −29
Original line number Diff line number Diff line
@@ -367,9 +367,6 @@ static int remove_ftrace_list_ops(struct ftrace_ops **list, 


static int __register_ftrace_function(struct ftrace_ops *ops)

{

	if (unlikely(ftrace_disabled))

		return -ENODEV;



	if (FTRACE_WARN_ON(ops == &global_ops))

		return -EINVAL;
@@ -428,9 +425,6 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) 
{

	int ret;



	if (ftrace_disabled)

		return -ENODEV;



	if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))

		return -EBUSY;
@@ -2088,10 +2082,15 @@ static void ftrace_startup_enable(int command) 
static int ftrace_startup(struct ftrace_ops *ops, int command)

{

	bool hash_enable = true;

	int ret;



	if (unlikely(ftrace_disabled))

		return -ENODEV;



	ret = __register_ftrace_function(ops);

	if (ret)

		return ret;



	ftrace_start_up++;

	command |= FTRACE_UPDATE_CALLS;
@@ -2113,12 +2112,17 @@ static int ftrace_startup(struct ftrace_ops *ops, int command) 
	return 0;

}



static void ftrace_shutdown(struct ftrace_ops *ops, int command)

static int ftrace_shutdown(struct ftrace_ops *ops, int command)

{

	bool hash_disable = true;

	int ret;



	if (unlikely(ftrace_disabled))

		return;

		return -ENODEV;



	ret = __unregister_ftrace_function(ops);

	if (ret)

		return ret;



	ftrace_start_up--;

	/*
@@ -2153,9 +2157,10 @@ static void ftrace_shutdown(struct ftrace_ops *ops, int command) 
	}



	if (!command || !ftrace_enabled)

		return;

		return 0;



	ftrace_run_update_code(command);

	return 0;

}



static void ftrace_startup_sysctl(void)
@@ -3060,8 +3065,6 @@ static void __enable_ftrace_function_probe(void) 
	if (i == FTRACE_FUNC_HASHSIZE)

		return;



	ret = __register_ftrace_function(&trace_probe_ops);

	if (!ret)

	ret = ftrace_startup(&trace_probe_ops, 0);



	ftrace_probe_registered = 1;
@@ -3069,7 +3072,6 @@ static void __enable_ftrace_function_probe(void) 


static void __disable_ftrace_function_probe(void)

{

	int ret;

	int i;



	if (!ftrace_probe_registered)
@@ -3082,8 +3084,6 @@ static void __disable_ftrace_function_probe(void) 
	}



	/* no more funcs left */

	ret = __unregister_ftrace_function(&trace_probe_ops);

	if (!ret)

	ftrace_shutdown(&trace_probe_ops, 0);



	ftrace_probe_registered = 0;
@@ -4368,10 +4368,13 @@ static inline void ftrace_startup_enable(int command) { } 
/* Keep as macros so we do not need to define the commands */

# define ftrace_startup(ops, command)					\

	({								\

		int ___ret = __register_ftrace_function(ops);		\

		if (!___ret)						\

			(ops)->flags |= FTRACE_OPS_FL_ENABLED;		\

		0;					\

		___ret;							\

	})

# define ftrace_shutdown(ops, command)	do { } while (0)

# define ftrace_shutdown(ops, command) __unregister_ftrace_function(ops)



# define ftrace_startup_sysctl()	do { } while (0)

# define ftrace_shutdown_sysctl()	do { } while (0)
@@ -4780,8 +4783,6 @@ int register_ftrace_function(struct ftrace_ops *ops) 


	mutex_lock(&ftrace_lock);



	ret = __register_ftrace_function(ops);

	if (!ret)

	ret = ftrace_startup(ops, 0);



	mutex_unlock(&ftrace_lock);
@@ -4801,9 +4802,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops) 
	int ret;



	mutex_lock(&ftrace_lock);

	ret = __unregister_ftrace_function(ops);

	if (!ret)

		ftrace_shutdown(ops, 0);

	ret = ftrace_shutdown(ops, 0);

	mutex_unlock(&ftrace_lock);



	return ret;
@@ -4997,6 +4996,13 @@ ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, 
	return NOTIFY_DONE;

}



/* Just a place holder for function graph */

static struct ftrace_ops fgraph_ops __read_mostly = {

	.func		= ftrace_stub,

	.flags		= FTRACE_OPS_FL_STUB | FTRACE_OPS_FL_GLOBAL |

				FTRACE_OPS_FL_RECURSION_SAFE,

};



int register_ftrace_graph(trace_func_graph_ret_t retfunc,

			trace_func_graph_ent_t entryfunc)

{
@@ -5023,7 +5029,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc, 
	ftrace_graph_return = retfunc;

	ftrace_graph_entry = entryfunc;



	ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);

	ret = ftrace_startup(&fgraph_ops, FTRACE_START_FUNC_RET);



out:

	mutex_unlock(&ftrace_lock);
@@ -5040,7 +5046,7 @@ void unregister_ftrace_graph(void) 
	ftrace_graph_active--;

	ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;

	ftrace_graph_entry = ftrace_graph_entry_stub;

	ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET);

	ftrace_shutdown(&fgraph_ops, FTRACE_STOP_FUNC_RET);

	unregister_pm_notifier(&ftrace_suspend_notifier);

	unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);

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