Commit 7ead8b83 authored by Li Zefan's avatar Li Zefan Committed by Ingo Molnar
Browse files

tracing/events: Add module tracepoints 



Add trace points to trace module_load, module_free, module_get,
module_put and module_request, and use trace_event facility to
get the trace output.

Here's the sample output:

     TASK-PID    CPU#    TIMESTAMP  FUNCTION
        | |       |          |         |
    <...>-42    [000]     1.758380: module_request: fb0 wait=1 call_site=fb_open
    ...
    <...>-60    [000]     3.269403: module_load: scsi_wait_scan
    <...>-60    [000]     3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0
    <...>-61    [001]     3.273168: module_free: scsi_wait_scan
    ...
    <...>-1021  [000]    13.836081: module_load: sunrpc
    <...>-1021  [000]    13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1
    <...>-1027  [000]    13.848098: module_get: sunrpc call_site=try_module_get refcnt=0
    <...>-1027  [000]    13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1
    <...>-1027  [000]    13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0
    ...
 modprobe-2587  [001]  1088.437213: module_load: trace_events_sample F
 modprobe-2587  [001]  1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0

Note:

- the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0

- the module refcnt is percpu, so it can be negative in a
  specific cpu

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 60d970c2

include/linux/module.h

+11 −3
Original line number Diff line number Diff line
@@ -17,10 +17,12 @@ 
#include <linux/moduleparam.h>

#include <linux/marker.h>

#include <linux/tracepoint.h>

#include <asm/local.h>



#include <asm/local.h>

#include <asm/module.h>



#include <trace/events/module.h>



/* Not Yet Implemented */

#define MODULE_SUPPORTED_DEVICE(name)
@@ -462,7 +464,10 @@ static inline local_t *__module_ref_addr(struct module *mod, int cpu) 
static inline void __module_get(struct module *module)

{

	if (module) {

		local_inc(__module_ref_addr(module, get_cpu()));

		unsigned int cpu = get_cpu();

		local_inc(__module_ref_addr(module, cpu));

		trace_module_get(module, _THIS_IP_,

				 local_read(__module_ref_addr(module, cpu)));

		put_cpu();

	}

}
@@ -473,8 +478,11 @@ static inline int try_module_get(struct module *module) 


	if (module) {

		unsigned int cpu = get_cpu();

		if (likely(module_is_live(module)))

		if (likely(module_is_live(module))) {

			local_inc(__module_ref_addr(module, cpu));

			trace_module_get(module, _THIS_IP_,

				local_read(__module_ref_addr(module, cpu)));

		}

		else

			ret = 0;

		put_cpu();

include/trace/events/module.h

0 → 100644
+126 −0
Original line number Diff line number Diff line 
#undef TRACE_SYSTEM

#define TRACE_SYSTEM module



#if !defined(_TRACE_MODULE_H) || defined(TRACE_HEADER_MULTI_READ)

#define _TRACE_MODULE_H



#include <linux/tracepoint.h>



#ifdef CONFIG_MODULES



struct module;



#define show_module_flags(flags) __print_flags(flags, "",	\

	{ (1UL << TAINT_PROPRIETARY_MODULE),	"P" },		\

	{ (1UL << TAINT_FORCED_MODULE),		"F" },		\

	{ (1UL << TAINT_CRAP),			"C" })



TRACE_EVENT(module_load,



	TP_PROTO(struct module *mod),



	TP_ARGS(mod),



	TP_STRUCT__entry(

		__field(	unsigned int,	taints		)

		__string(	name,		mod->name	)

	),



	TP_fast_assign(

		__entry->taints = mod->taints;

		__assign_str(name, mod->name);

	),



	TP_printk("%s %s", __get_str(name), show_module_flags(__entry->taints))

);



TRACE_EVENT(module_free,



	TP_PROTO(struct module *mod),



	TP_ARGS(mod),



	TP_STRUCT__entry(

		__string(	name,		mod->name	)

	),



	TP_fast_assign(

		__assign_str(name, mod->name);

	),



	TP_printk("%s", __get_str(name))

);



TRACE_EVENT(module_get,



	TP_PROTO(struct module *mod, unsigned long ip, int refcnt),



	TP_ARGS(mod, ip, refcnt),



	TP_STRUCT__entry(

		__field(	unsigned long,	ip		)

		__field(	int,		refcnt		)

		__string(	name,		mod->name	)

	),



	TP_fast_assign(

		__entry->ip	= ip;

		__entry->refcnt	= refcnt;

		__assign_str(name, mod->name);

	),



	TP_printk("%s call_site=%pf refcnt=%d",

		  __get_str(name), (void *)__entry->ip, __entry->refcnt)

);



TRACE_EVENT(module_put,



	TP_PROTO(struct module *mod, unsigned long ip, int refcnt),



	TP_ARGS(mod, ip, refcnt),



	TP_STRUCT__entry(

		__field(	unsigned long,	ip		)

		__field(	int,		refcnt		)

		__string(	name,		mod->name	)

	),



	TP_fast_assign(

		__entry->ip	= ip;

		__entry->refcnt	= refcnt;

		__assign_str(name, mod->name);

	),



	TP_printk("%s call_site=%pf refcnt=%d",

		  __get_str(name), (void *)__entry->ip, __entry->refcnt)

);



TRACE_EVENT(module_request,



	TP_PROTO(char *name, bool wait, unsigned long ip),



	TP_ARGS(name, wait, ip),



	TP_STRUCT__entry(

		__field(	bool,		wait		)

		__field(	unsigned long,	ip		)

		__string(	name,		name		)

	),



	TP_fast_assign(

		__entry->wait	= wait;

		__entry->ip	= ip;

		__assign_str(name, name);

	),



	TP_printk("%s wait=%d call_site=%pf",

		  __get_str(name), (int)__entry->wait, (void *)__entry->ip)

);



#endif /* CONFIG_MODULES */



#endif /* _TRACE_MODULE_H */



/* This part must be outside protection */

#include <trace/define_trace.h>

kernel/kmod.c

+4 −0
Original line number Diff line number Diff line
@@ -37,6 +37,8 @@ 
#include <linux/suspend.h>

#include <asm/uaccess.h>



#include <trace/events/module.h>



extern int max_threads;



static struct workqueue_struct *khelper_wq;
@@ -108,6 +110,8 @@ int __request_module(bool wait, const char *fmt, ...) 
		return -ENOMEM;

	}



	trace_module_request(module_name, wait, _RET_IP_);



	ret = call_usermodehelper(modprobe_path, argv, envp,

			wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);

	atomic_dec(&kmod_concurrent);

kernel/module.c

+11 −0
Original line number Diff line number Diff line
@@ -55,6 +55,11 @@ 
#include <linux/percpu.h>

#include <linux/kmemleak.h>



#define CREATE_TRACE_POINTS

#include <trace/events/module.h>



EXPORT_TRACEPOINT_SYMBOL(module_get);



#if 0

#define DEBUGP printk

#else
@@ -940,6 +945,8 @@ void module_put(struct module *module) 
	if (module) {

		unsigned int cpu = get_cpu();

		local_dec(__module_ref_addr(module, cpu));

		trace_module_put(module, _RET_IP_,

				 local_read(__module_ref_addr(module, cpu)));

		/* Maybe they're waiting for us to drop reference? */

		if (unlikely(!module_is_live(module)))

			wake_up_process(module->waiter);
@@ -1491,6 +1498,8 @@ static int __unlink_module(void *_mod) 
/* Free a module, remove from lists, etc (must hold module_mutex). */

static void free_module(struct module *mod)

{

	trace_module_free(mod);



	/* Delete from various lists */

	stop_machine(__unlink_module, mod, NULL);

	remove_notes_attrs(mod);
@@ -2358,6 +2367,8 @@ static noinline struct module *load_module(void __user *umod, 
	/* Get rid of temporary copy */

	vfree(hdr);



	trace_module_load(mod);



	/* Done! */

	return mod;

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