Commit 4c174688 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull tracing updates from Steven Rostedt:
 "New features for this release:

   - Pretty much a full rewrite of the processing of function plugins.
     i.e. echo do_IRQ:stacktrace > set_ftrace_filter

   - The rewrite was needed to add plugins to be unique to tracing
     instances. i.e. mkdir instance/foo; cd instances/foo; echo
     do_IRQ:stacktrace > set_ftrace_filter The old way was written very
     hacky. This removes a lot of those hacks.

   - New "function-fork" tracing option. When set, pids in the
     set_ftrace_pid will have their children added when the processes
     with their pids listed in the set_ftrace_pid file forks.

   - Exposure of "maxactive" for kretprobe in kprobe_events

   - Allow for builtin init functions to be traced by the function
     tracer (via the kernel command line). Module init function tracing
     will come in the next release.

   - Added more selftests, and have selftests also test in an instance"

* tag 'trace-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (60 commits)
  ring-buffer: Return reader page back into existing ring buffer
  selftests: ftrace: Allow some event trigger tests to run in an instance
  selftests: ftrace: Have some basic tests run in a tracing instance too
  selftests: ftrace: Have event tests also run in an tracing instance
  selftests: ftrace: Make func_event_triggers and func_traceonoff_triggers tests do instances
  selftests: ftrace: Allow some tests to be run in a tracing instance
  tracing/ftrace: Allow for instances to trigger their own stacktrace probes
  tracing/ftrace: Allow for the traceonoff probe be unique to instances
  tracing/ftrace: Enable snapshot function trigger to work with instances
  tracing/ftrace: Allow instances to have their own function probes
  tracing/ftrace: Add a better way to pass data via the probe functions
  ftrace: Dynamically create the probe ftrace_ops for the trace_array
  tracing: Pass the trace_array into ftrace_probe_ops functions
  tracing: Have the trace_array hold the list of registered func probes
  ftrace: If the hash for a probe fails to update then free what was initialized
  ftrace: Have the function probes call their own function
  ftrace: Have each function probe use its own ftrace_ops
  ftrace: Have unregister_ftrace_function_probe_func() return a value
  ftrace: Add helper function ftrace_hash_move_and_update_ops()
  ftrace: Remove data field from ftrace_func_probe structure
  ...
parents 9c35baf6 73a757e6

Documentation/trace/kprobetrace.txt

+4 −1
Original line number Diff line number Diff line
@@ -24,7 +24,7 @@ current_tracer. Instead of that, add probe points via 
Synopsis of kprobe_events

-------------------------

  p[:[GRP/]EVENT] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS]	: Set a probe

  r[:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS]		: Set a return probe

  r[MAXACTIVE][:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS]	: Set a return probe

  -:[GRP/]EVENT						: Clear a probe



 GRP		: Group name. If omitted, use "kprobes" for it.
@@ -33,6 +33,9 @@ Synopsis of kprobe_events 
 MOD		: Module name which has given SYM.

 SYM[+offs]	: Symbol+offset where the probe is inserted.

 MEMADDR	: Address where the probe is inserted.

 MAXACTIVE	: Maximum number of instances of the specified function that

		  can be probed simultaneously, or 0 for the default value

		  as defined in Documentation/kprobes.txt section 1.3.1.



 FETCHARGS	: Arguments. Each probe can have up to 128 args.

  %REG		: Fetch register REG

arch/x86/kernel/ftrace.c

+7 −1
Original line number Diff line number Diff line
@@ -533,7 +533,13 @@ static void do_sync_core(void *data) 


static void run_sync(void)

{

	int enable_irqs = irqs_disabled();

	int enable_irqs;



	/* No need to sync if there's only one CPU */

	if (num_online_cpus() == 1)

		return;



	enable_irqs = irqs_disabled();



	/* We may be called with interrupts disabled (on bootup). */

	if (enable_irqs)

include/linux/ftrace.h

+47 −45
Original line number Diff line number Diff line
@@ -42,8 +42,10 @@ 
/* Main tracing buffer and events set up */

#ifdef CONFIG_TRACING

void trace_init(void);

void early_trace_init(void);

#else

static inline void trace_init(void) { }

static inline void early_trace_init(void) { }

#endif



struct module;
@@ -144,6 +146,10 @@ struct ftrace_ops_hash { 
	struct ftrace_hash		*filter_hash;

	struct mutex			regex_lock;

};



void ftrace_free_init_mem(void);

#else

static inline void ftrace_free_init_mem(void) { }

#endif



/*
@@ -260,6 +266,7 @@ static inline int ftrace_nr_registered_ops(void) 
}

static inline void clear_ftrace_function(void) { }

static inline void ftrace_kill(void) { }

static inline void ftrace_free_init_mem(void) { }

#endif /* CONFIG_FUNCTION_TRACER */



#ifdef CONFIG_STACK_TRACER
@@ -279,15 +286,45 @@ int 
stack_trace_sysctl(struct ctl_table *table, int write,

		   void __user *buffer, size_t *lenp,

		   loff_t *ppos);

#endif



struct ftrace_func_command {

	struct list_head	list;

	char			*name;

	int			(*func)(struct ftrace_hash *hash,

					char *func, char *cmd,

					char *params, int enable);

};

/* DO NOT MODIFY THIS VARIABLE DIRECTLY! */

DECLARE_PER_CPU(int, disable_stack_tracer);



/**

 * stack_tracer_disable - temporarily disable the stack tracer

 *

 * There's a few locations (namely in RCU) where stack tracing

 * cannot be executed. This function is used to disable stack

 * tracing during those critical sections.

 *

 * This function must be called with preemption or interrupts

 * disabled and stack_tracer_enable() must be called shortly after

 * while preemption or interrupts are still disabled.

 */

static inline void stack_tracer_disable(void)

{

	/* Preemption or interupts must be disabled */

	if (IS_ENABLED(CONFIG_PREEMPT_DEBUG))

		WARN_ON_ONCE(!preempt_count() || !irqs_disabled());

	this_cpu_inc(disable_stack_tracer);

}



/**

 * stack_tracer_enable - re-enable the stack tracer

 *

 * After stack_tracer_disable() is called, stack_tracer_enable()

 * must be called shortly afterward.

 */

static inline void stack_tracer_enable(void)

{

	if (IS_ENABLED(CONFIG_PREEMPT_DEBUG))

		WARN_ON_ONCE(!preempt_count() || !irqs_disabled());

	this_cpu_dec(disable_stack_tracer);

}

#else

static inline void stack_tracer_disable(void) { }

static inline void stack_tracer_enable(void) { }

#endif



#ifdef CONFIG_DYNAMIC_FTRACE
@@ -315,30 +352,6 @@ void ftrace_bug(int err, struct dyn_ftrace *rec); 


struct seq_file;



struct ftrace_probe_ops {

	void			(*func)(unsigned long ip,

					unsigned long parent_ip,

					void **data);

	int			(*init)(struct ftrace_probe_ops *ops,

					unsigned long ip, void **data);

	void			(*free)(struct ftrace_probe_ops *ops,

					unsigned long ip, void **data);

	int			(*print)(struct seq_file *m,

					 unsigned long ip,

					 struct ftrace_probe_ops *ops,

					 void *data);

};



extern int

register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,

			      void *data);

extern void

unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,

				void *data);

extern void

unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);

extern void unregister_ftrace_function_probe_all(char *glob);



extern int ftrace_text_reserved(const void *start, const void *end);



extern int ftrace_nr_registered_ops(void);
@@ -400,9 +413,6 @@ void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); 
void ftrace_free_filter(struct ftrace_ops *ops);

void ftrace_ops_set_global_filter(struct ftrace_ops *ops);



int register_ftrace_command(struct ftrace_func_command *cmd);

int unregister_ftrace_command(struct ftrace_func_command *cmd);



enum {

	FTRACE_UPDATE_CALLS		= (1 << 0),

	FTRACE_DISABLE_CALLS		= (1 << 1),
@@ -433,8 +443,8 @@ enum { 
	FTRACE_ITER_FILTER	= (1 << 0),

	FTRACE_ITER_NOTRACE	= (1 << 1),

	FTRACE_ITER_PRINTALL	= (1 << 2),

	FTRACE_ITER_DO_HASH	= (1 << 3),

	FTRACE_ITER_HASH	= (1 << 4),

	FTRACE_ITER_DO_PROBES	= (1 << 3),

	FTRACE_ITER_PROBE	= (1 << 4),

	FTRACE_ITER_ENABLED	= (1 << 5),

};
@@ -618,14 +628,6 @@ static inline void ftrace_enable_daemon(void) { } 
static inline void ftrace_module_init(struct module *mod) { }

static inline void ftrace_module_enable(struct module *mod) { }

static inline void ftrace_release_mod(struct module *mod) { }

static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)

{

	return -EINVAL;

}

static inline __init int unregister_ftrace_command(char *cmd_name)

{

	return -EINVAL;

}

static inline int ftrace_text_reserved(const void *start, const void *end)

{

	return 0;

include/linux/init.h

+3 −1
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ 


/* These are for everybody (although not all archs will actually

   discard it in modules) */

#define __init		__section(.init.text) __cold notrace __latent_entropy

#define __init		__section(.init.text) __cold __inittrace __latent_entropy

#define __initdata	__section(.init.data)

#define __initconst	__section(.init.rodata)

#define __exitdata	__section(.exit.data)
@@ -68,8 +68,10 @@ 


#ifdef MODULE

#define __exitused

#define __inittrace notrace

#else

#define __exitused  __used

#define __inittrace

#endif



#define __exit          __section(.exit.text) __exitused __cold notrace

include/linux/rcupdate.h

+5 −0
Original line number Diff line number Diff line
@@ -97,6 +97,7 @@ void do_trace_rcu_torture_read(const char *rcutorturename, 
			       unsigned long secs,

			       unsigned long c_old,

			       unsigned long c);

bool rcu_irq_enter_disabled(void);

#else

static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,

					  int *flags,
@@ -113,6 +114,10 @@ static inline void rcutorture_record_test_transition(void) 
static inline void rcutorture_record_progress(unsigned long vernum)

{

}

static inline bool rcu_irq_enter_disabled(void)

{

	return false;

}

#ifdef CONFIG_RCU_TRACE

void do_trace_rcu_torture_read(const char *rcutorturename,

			       struct rcu_head *rhp,

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