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Commit 540b7b8d authored by Li Zefan's avatar Li Zefan Committed by Ingo Molnar
Browse files

tracing/syscalls: Add filtering support 



Add filtering support for syscall events:

 # echo 'mode == 0666' > events/syscalls/sys_enter_open
 # echo 'ret == 0' > events/syscalls/sys_exit_open
 # echo 1 > events/syscalls/sys_enter_open
 # echo 1 > events/syscalls/sys_exit_open
 # cat trace
 ...
   modprobe-3084 [001] 117.463140: sys_open(filename: 917d3e8, flags: 0, mode: 1b6)
   modprobe-3084 [001] 117.463176: sys_open -> 0x0
       less-3086 [001] 117.510455: sys_open(filename: 9c6bdb8, flags: 8000, mode: 1b6)
   sendmail-2574 [001] 122.145840: sys_open(filename: b807a365, flags: 0, mode: 1b6)
 ...

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A8BAFCB.1040006@cn.fujitsu.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e647d6b3

include/linux/ftrace_event.h

+3 −2
Original line number Diff line number Diff line
@@ -140,8 +140,9 @@ extern int filter_current_check_discard(struct ftrace_event_call *call, 
					void *rec,

					struct ring_buffer_event *event);



extern int trace_define_field(struct ftrace_event_call *call, char *type,

			      char *name, int offset, int size, int is_signed);

extern int trace_define_field(struct ftrace_event_call *call,

			      const char *type, const char *name,

			      int offset, int size, int is_signed);

extern int trace_define_common_fields(struct ftrace_event_call *call);



#define is_signed_type(type)	(((type)(-1)) < 0)

include/linux/syscalls.h

+11 −5
Original line number Diff line number Diff line
@@ -190,6 +190,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \ 
		.event                  = &event_syscall_enter,		\

		.raw_init		= init_enter_##sname,		\

		.show_format		= syscall_enter_format,		\

		.define_fields		= syscall_enter_define_fields,	\

		.regfunc		= reg_event_syscall_enter,	\

		.unregfunc		= unreg_event_syscall_enter,	\

		.data			= "sys"#sname,			\
@@ -226,6 +227,7 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \ 
		.event                  = &event_syscall_exit,		\

		.raw_init		= init_exit_##sname,		\

		.show_format		= syscall_exit_format,		\

		.define_fields		= syscall_exit_define_fields,	\

		.regfunc		= reg_event_syscall_exit,	\

		.unregfunc		= unreg_event_syscall_exit,	\

		.data			= "sys"#sname,			\
@@ -233,6 +235,8 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \ 
	}



#define SYSCALL_METADATA(sname, nb)				\

	SYSCALL_TRACE_ENTER_EVENT(sname);			\

	SYSCALL_TRACE_EXIT_EVENT(sname);			\

	static const struct syscall_metadata __used		\

	  __attribute__((__aligned__(4)))			\

	  __attribute__((section("__syscalls_metadata")))	\
@@ -241,20 +245,22 @@ static void prof_sysexit_disable_##sname(struct ftrace_event_call *event_call) \ 
		.nb_args 	= nb,				\

		.types		= types_##sname,		\

		.args		= args_##sname,			\

	};							\

	SYSCALL_TRACE_ENTER_EVENT(sname);			\

	SYSCALL_TRACE_EXIT_EVENT(sname);

		.enter_event	= &event_enter_##sname,		\

		.exit_event	= &event_exit_##sname,		\

	};



#define SYSCALL_DEFINE0(sname)					\

	SYSCALL_TRACE_ENTER_EVENT(_##sname);			\

	SYSCALL_TRACE_EXIT_EVENT(_##sname);			\

	static const struct syscall_metadata __used		\

	  __attribute__((__aligned__(4)))			\

	  __attribute__((section("__syscalls_metadata")))	\

	  __syscall_meta_##sname = {				\

		.name 		= "sys_"#sname,			\

		.nb_args 	= 0,				\

		.enter_event	= &event_enter__##sname,	\

		.exit_event	= &event_exit__##sname,		\

	};							\

	SYSCALL_TRACE_ENTER_EVENT(_##sname);			\

	SYSCALL_TRACE_EXIT_EVENT(_##sname);			\

	asmlinkage long sys_##sname(void)

#else

#define SYSCALL_DEFINE0(name)	   asmlinkage long sys_##name(void)

include/trace/syscall.h

+7 −0
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ DECLARE_TRACE_WITH_CALLBACK(syscall_exit, 
 * @args: list of args as strings (args[i] matches types[i])

 * @enter_id: associated ftrace enter event id

 * @exit_id: associated ftrace exit event id

 * @enter_event: associated syscall_enter trace event

 * @exit_event: associated syscall_exit trace event

 */

struct syscall_metadata {

	const char	*name;
@@ -42,6 +44,9 @@ struct syscall_metadata { 
	const char	**args;

	int		enter_id;

	int		exit_id;



	struct ftrace_event_call *enter_event;

	struct ftrace_event_call *exit_event;

};



#ifdef CONFIG_FTRACE_SYSCALLS
@@ -59,6 +64,8 @@ extern int syscall_enter_format(struct ftrace_event_call *call, 
				struct trace_seq *s);

extern int syscall_exit_format(struct ftrace_event_call *call,

				struct trace_seq *s);

extern int syscall_enter_define_fields(struct ftrace_event_call *call);

extern int syscall_exit_define_fields(struct ftrace_event_call *call);

enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags);

enum print_line_t print_syscall_exit(struct trace_iterator *iter, int flags);

#endif

kernel/trace/trace_events.c

+3 −2
Original line number Diff line number Diff line
@@ -27,8 +27,8 @@ DEFINE_MUTEX(event_mutex); 


LIST_HEAD(ftrace_events);



int trace_define_field(struct ftrace_event_call *call, char *type,

		       char *name, int offset, int size, int is_signed)

int trace_define_field(struct ftrace_event_call *call, const char *type,

		       const char *name, int offset, int size, int is_signed)

{

	struct ftrace_event_field *field;
@@ -83,6 +83,7 @@ int trace_define_common_fields(struct ftrace_event_call *call) 


	return ret;

}

EXPORT_SYMBOL_GPL(trace_define_common_fields);



#ifdef CONFIG_MODULES

kernel/trace/trace_syscalls.c

+47 −4
Original line number Diff line number Diff line
@@ -165,6 +165,49 @@ int syscall_exit_format(struct ftrace_event_call *call, struct trace_seq *s) 
	return trace_seq_printf(s, "\nprint fmt: \"0x%%lx\", REC->ret\n");

}



int syscall_enter_define_fields(struct ftrace_event_call *call)

{

	struct syscall_trace_enter trace;

	struct syscall_metadata *meta;

	int ret;

	int nr;

	int i;

	int offset = offsetof(typeof(trace), args);



	nr = syscall_name_to_nr(call->data);

	meta = syscall_nr_to_meta(nr);



	if (!meta)

		return 0;



	ret = trace_define_common_fields(call);

	if (ret)

		return ret;



	for (i = 0; i < meta->nb_args; i++) {

		ret = trace_define_field(call, meta->types[i],

					 meta->args[i], offset,

					 sizeof(unsigned long), 0);

		offset += sizeof(unsigned long);

	}



	return ret;

}



int syscall_exit_define_fields(struct ftrace_event_call *call)

{

	struct syscall_trace_exit trace;

	int ret;



	ret = trace_define_common_fields(call);

	if (ret)

		return ret;



	ret = trace_define_field(call, SYSCALL_FIELD(unsigned long, ret), 0);



	return ret;

}



void ftrace_syscall_enter(struct pt_regs *regs, long id)

{

	struct syscall_trace_enter *entry;
@@ -192,8 +235,8 @@ void ftrace_syscall_enter(struct pt_regs *regs, long id) 
	entry->nr = syscall_nr;

	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);



	if (!filter_current_check_discard(sys_data->enter_event, entry, event))

		trace_current_buffer_unlock_commit(event, 0, 0);

	trace_wake_up();

}



void ftrace_syscall_exit(struct pt_regs *regs, long ret)
@@ -220,8 +263,8 @@ void ftrace_syscall_exit(struct pt_regs *regs, long ret) 
	entry->nr = syscall_nr;

	entry->ret = syscall_get_return_value(current, regs);



	if (!filter_current_check_discard(sys_data->exit_event, entry, event))

		trace_current_buffer_unlock_commit(event, 0, 0);

	trace_wake_up();

}



int reg_event_syscall_enter(void *ptr)