[net-next-2.6.git] / kernel / trace / trace_syscalls.c

#include <trace/syscall.h>
#include <trace/events/syscalls.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
#include <linux/perf_event.h>
#include <asm/syscall.h>

#include "trace_output.h"
#include "trace.h"

static DEFINE_MUTEX(syscall_trace_lock);
static int sys_refcount_enter;
static int sys_refcount_exit;
static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);

static int syscall_enter_register(struct ftrace_event_call *event,
				 enum trace_reg type);
static int syscall_exit_register(struct ftrace_event_call *event,
				 enum trace_reg type);

static int syscall_enter_define_fields(struct ftrace_event_call *call);
static int syscall_exit_define_fields(struct ftrace_event_call *call);

/* All syscall exit events have the same fields */
static LIST_HEAD(syscall_exit_fields);

static struct list_head *
syscall_get_enter_fields(struct ftrace_event_call *call)
{
	struct syscall_metadata *entry = call->data;

	return &entry->enter_fields;
}

static struct list_head *
syscall_get_exit_fields(struct ftrace_event_call *call)
{
	return &syscall_exit_fields;
}

struct trace_event_functions enter_syscall_print_funcs = {
	.trace                  = print_syscall_enter,
};

struct trace_event_functions exit_syscall_print_funcs = {
	.trace                  = print_syscall_exit,
};

struct ftrace_event_class event_class_syscall_enter = {
	.system			= "syscalls",
	.reg			= syscall_enter_register,
	.define_fields		= syscall_enter_define_fields,
	.get_fields		= syscall_get_enter_fields,
	.raw_init		= init_syscall_trace,
};

struct ftrace_event_class event_class_syscall_exit = {
	.system			= "syscalls",
	.reg			= syscall_exit_register,
	.define_fields		= syscall_exit_define_fields,
	.get_fields		= syscall_get_exit_fields,
	.raw_init		= init_syscall_trace,
};

extern unsigned long __start_syscalls_metadata[];
extern unsigned long __stop_syscalls_metadata[];

static struct syscall_metadata **syscalls_metadata;

static struct syscall_metadata *find_syscall_meta(unsigned long syscall)
{
	struct syscall_metadata *start;
	struct syscall_metadata *stop;
	char str[KSYM_SYMBOL_LEN];


	start = (struct syscall_metadata *)__start_syscalls_metadata;
	stop = (struct syscall_metadata *)__stop_syscalls_metadata;
	kallsyms_lookup(syscall, NULL, NULL, NULL, str);

	for ( ; start < stop; start++) {
		/*
		 * Only compare after the "sys" prefix. Archs that use
		 * syscall wrappers may have syscalls symbols aliases prefixed
		 * with "SyS" instead of "sys", leading to an unwanted
		 * mismatch.
		 */
		if (start->name && !strcmp(start->name + 3, str + 3))
			return start;
	}
	return NULL;
}

static struct syscall_metadata *syscall_nr_to_meta(int nr)
{
	if (!syscalls_metadata || nr >= NR_syscalls || nr < 0)
		return NULL;

	return syscalls_metadata[nr];
}

enum print_line_t
print_syscall_enter(struct trace_iterator *iter, int flags,
		    struct trace_event *event)
{
	struct trace_seq *s = &iter->seq;
	struct trace_entry *ent = iter->ent;
	struct syscall_trace_enter *trace;
	struct syscall_metadata *entry;
	int i, ret, syscall;

	trace = (typeof(trace))ent;
	syscall = trace->nr;
	entry = syscall_nr_to_meta(syscall);

	if (!entry)
		goto end;

	if (entry->enter_event->event.type != ent->type) {
		WARN_ON_ONCE(1);
		goto end;
	}

	ret = trace_seq_printf(s, "%s(", entry->name);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	for (i = 0; i < entry->nb_args; i++) {
		/* parameter types */
		if (trace_flags & TRACE_ITER_VERBOSE) {
			ret = trace_seq_printf(s, "%s ", entry->types[i]);
			if (!ret)
				return TRACE_TYPE_PARTIAL_LINE;
		}
		/* parameter values */
		ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i],
				       trace->args[i],
				       i == entry->nb_args - 1 ? "" : ", ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	ret = trace_seq_putc(s, ')');
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

end:
	ret =  trace_seq_putc(s, '\n');
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

enum print_line_t
print_syscall_exit(struct trace_iterator *iter, int flags,
		   struct trace_event *event)
{
	struct trace_seq *s = &iter->seq;
	struct trace_entry *ent = iter->ent;
	struct syscall_trace_exit *trace;
	int syscall;
	struct syscall_metadata *entry;
	int ret;

	trace = (typeof(trace))ent;
	syscall = trace->nr;
	entry = syscall_nr_to_meta(syscall);

	if (!entry) {
		trace_seq_printf(s, "\n");
		return TRACE_TYPE_HANDLED;
	}

	if (entry->exit_event->event.type != ent->type) {
		WARN_ON_ONCE(1);
		return TRACE_TYPE_UNHANDLED;
	}

	ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
				trace->ret);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

extern char *__bad_type_size(void);

#define SYSCALL_FIELD(type, name)					\
	sizeof(type) != sizeof(trace.name) ?				\
		__bad_type_size() :					\
		#type, #name, offsetof(typeof(trace), name),		\
		sizeof(trace.name), is_signed_type(type)

static
int  __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
{
	int i;
	int pos = 0;

	/* When len=0, we just calculate the needed length */
#define LEN_OR_ZERO (len ? len - pos : 0)

	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
	for (i = 0; i < entry->nb_args; i++) {
		pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
				entry->args[i], sizeof(unsigned long),
				i == entry->nb_args - 1 ? "" : ", ");
	}
	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");

	for (i = 0; i < entry->nb_args; i++) {
		pos += snprintf(buf + pos, LEN_OR_ZERO,
				", ((unsigned long)(REC->%s))", entry->args[i]);
	}

#undef LEN_OR_ZERO

	/* return the length of print_fmt */
	return pos;
}

static int set_syscall_print_fmt(struct ftrace_event_call *call)
{
	char *print_fmt;
	int len;
	struct syscall_metadata *entry = call->data;

	if (entry->enter_event != call) {
		call->print_fmt = "\"0x%lx\", REC->ret";
		return 0;
	}

	/* First: called with 0 length to calculate the needed length */
	len = __set_enter_print_fmt(entry, NULL, 0);

	print_fmt = kmalloc(len + 1, GFP_KERNEL);
	if (!print_fmt)
		return -ENOMEM;

	/* Second: actually write the @print_fmt */
	__set_enter_print_fmt(entry, print_fmt, len + 1);
	call->print_fmt = print_fmt;

	return 0;
}

static void free_syscall_print_fmt(struct ftrace_event_call *call)
{
	struct syscall_metadata *entry = call->data;

	if (entry->enter_event == call)
		kfree(call->print_fmt);
}

static int syscall_enter_define_fields(struct ftrace_event_call *call)
{
	struct syscall_trace_enter trace;
	struct syscall_metadata *meta = call->data;
	int ret;
	int i;
	int offset = offsetof(typeof(trace), args);

	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
	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,
					 FILTER_OTHER);
		offset += sizeof(unsigned long);
	}

	return ret;
}

static int syscall_exit_define_fields(struct ftrace_event_call *call)
{
	struct syscall_trace_exit trace;
	int ret;

	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
	if (ret)
		return ret;

	ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
				 FILTER_OTHER);

	return ret;
}

void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id)
{
	struct syscall_trace_enter *entry;
	struct syscall_metadata *sys_data;
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	int size;
	int syscall_nr;

	syscall_nr = syscall_get_nr(current, regs);
	if (syscall_nr < 0)
		return;
	if (!test_bit(syscall_nr, enabled_enter_syscalls))
		return;

	sys_data = syscall_nr_to_meta(syscall_nr);
	if (!sys_data)
		return;

	size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;

	event = trace_current_buffer_lock_reserve(&buffer,
			sys_data->enter_event->event.type, size, 0, 0);
	if (!event)
		return;

	entry = ring_buffer_event_data(event);
	entry->nr = syscall_nr;
	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);

	if (!filter_current_check_discard(buffer, sys_data->enter_event,
					  entry, event))
		trace_current_buffer_unlock_commit(buffer, event, 0, 0);
}

void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
{
	struct syscall_trace_exit *entry;
	struct syscall_metadata *sys_data;
	struct ring_buffer_event *event;
	struct ring_buffer *buffer;
	int syscall_nr;

	syscall_nr = syscall_get_nr(current, regs);
	if (syscall_nr < 0)
		return;
	if (!test_bit(syscall_nr, enabled_exit_syscalls))
		return;

	sys_data = syscall_nr_to_meta(syscall_nr);
	if (!sys_data)
		return;

	event = trace_current_buffer_lock_reserve(&buffer,
			sys_data->exit_event->event.type, sizeof(*entry), 0, 0);
	if (!event)
		return;

	entry = ring_buffer_event_data(event);
	entry->nr = syscall_nr;
	entry->ret = syscall_get_return_value(current, regs);

	if (!filter_current_check_discard(buffer, sys_data->exit_event,
					  entry, event))
		trace_current_buffer_unlock_commit(buffer, event, 0, 0);
}

int reg_event_syscall_enter(struct ftrace_event_call *call)
{
	int ret = 0;
	int num;

	num = ((struct syscall_metadata *)call->data)->syscall_nr;
	if (num < 0 || num >= NR_syscalls)
		return -ENOSYS;
	mutex_lock(&syscall_trace_lock);
	if (!sys_refcount_enter)
		ret = register_trace_sys_enter(ftrace_syscall_enter, NULL);
	if (!ret) {
		set_bit(num, enabled_enter_syscalls);
		sys_refcount_enter++;
	}
	mutex_unlock(&syscall_trace_lock);
	return ret;
}

void unreg_event_syscall_enter(struct ftrace_event_call *call)
{
	int num;

	num = ((struct syscall_metadata *)call->data)->syscall_nr;
	if (num < 0 || num >= NR_syscalls)
		return;
	mutex_lock(&syscall_trace_lock);
	sys_refcount_enter--;
	clear_bit(num, enabled_enter_syscalls);
	if (!sys_refcount_enter)
		unregister_trace_sys_enter(ftrace_syscall_enter, NULL);
	mutex_unlock(&syscall_trace_lock);
}

int reg_event_syscall_exit(struct ftrace_event_call *call)
{
	int ret = 0;
	int num;

	num = ((struct syscall_metadata *)call->data)->syscall_nr;
	if (num < 0 || num >= NR_syscalls)
		return -ENOSYS;
	mutex_lock(&syscall_trace_lock);
	if (!sys_refcount_exit)
		ret = register_trace_sys_exit(ftrace_syscall_exit, NULL);
	if (!ret) {
		set_bit(num, enabled_exit_syscalls);
		sys_refcount_exit++;
	}
	mutex_unlock(&syscall_trace_lock);
	return ret;
}

void unreg_event_syscall_exit(struct ftrace_event_call *call)
{
	int num;

	num = ((struct syscall_metadata *)call->data)->syscall_nr;
	if (num < 0 || num >= NR_syscalls)
		return;
	mutex_lock(&syscall_trace_lock);
	sys_refcount_exit--;
	clear_bit(num, enabled_exit_syscalls);
	if (!sys_refcount_exit)
		unregister_trace_sys_exit(ftrace_syscall_exit, NULL);
	mutex_unlock(&syscall_trace_lock);
}

int init_syscall_trace(struct ftrace_event_call *call)
{
	int id;

	if (set_syscall_print_fmt(call) < 0)
		return -ENOMEM;

	id = trace_event_raw_init(call);

	if (id < 0) {
		free_syscall_print_fmt(call);
		return id;
	}

	return id;
}

unsigned long __init arch_syscall_addr(int nr)
{
	return (unsigned long)sys_call_table[nr];
}

int __init init_ftrace_syscalls(void)
{
	struct syscall_metadata *meta;
	unsigned long addr;
	int i;

	syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) *
					NR_syscalls, GFP_KERNEL);
	if (!syscalls_metadata) {
		WARN_ON(1);
		return -ENOMEM;
	}

	for (i = 0; i < NR_syscalls; i++) {
		addr = arch_syscall_addr(i);
		meta = find_syscall_meta(addr);
		if (!meta)
			continue;

		meta->syscall_nr = i;
		syscalls_metadata[i] = meta;
	}

	return 0;
}
core_initcall(init_ftrace_syscalls);

#ifdef CONFIG_PERF_EVENTS

static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls);
static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls);
static int sys_perf_refcount_enter;
static int sys_perf_refcount_exit;

static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
{
	struct syscall_metadata *sys_data;
	struct syscall_trace_enter *rec;
	struct hlist_head *head;
	int syscall_nr;
	int rctx;
	int size;

	syscall_nr = syscall_get_nr(current, regs);
	if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
		return;

	sys_data = syscall_nr_to_meta(syscall_nr);
	if (!sys_data)
		return;

	/* get the size after alignment with the u32 buffer size field */
	size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
	size = ALIGN(size + sizeof(u32), sizeof(u64));
	size -= sizeof(u32);

	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
		      "perf buffer not large enough"))
		return;

	rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
				sys_data->enter_event->event.type, regs, &rctx);
	if (!rec)
		return;

	rec->nr = syscall_nr;
	syscall_get_arguments(current, regs, 0, sys_data->nb_args,
			       (unsigned long *)&rec->args);

	head = this_cpu_ptr(sys_data->enter_event->perf_events);
	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
}

int perf_sysenter_enable(struct ftrace_event_call *call)
{
	int ret = 0;
	int num;

	num = ((struct syscall_metadata *)call->data)->syscall_nr;

	mutex_lock(&syscall_trace_lock);
	if (!sys_perf_refcount_enter)
		ret = register_trace_sys_enter(perf_syscall_enter, NULL);
	if (ret) {
		pr_info("event trace: Could not activate"
				"syscall entry trace point");
	} else {
		set_bit(num, enabled_perf_enter_syscalls);
		sys_perf_refcount_enter++;
	}
	mutex_unlock(&syscall_trace_lock);
	return ret;
}

void perf_sysenter_disable(struct ftrace_event_call *call)
{
	int num;

	num = ((struct syscall_metadata *)call->data)->syscall_nr;

	mutex_lock(&syscall_trace_lock);
	sys_perf_refcount_enter--;
	clear_bit(num, enabled_perf_enter_syscalls);
	if (!sys_perf_refcount_enter)
		unregister_trace_sys_enter(perf_syscall_enter, NULL);
	mutex_unlock(&syscall_trace_lock);
}

static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
{
	struct syscall_metadata *sys_data;
	struct syscall_trace_exit *rec;
	struct hlist_head *head;
	int syscall_nr;
	int rctx;
	int size;

	syscall_nr = syscall_get_nr(current, regs);
	if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
		return;

	sys_data = syscall_nr_to_meta(syscall_nr);
	if (!sys_data)
		return;

	/* We can probably do that at build time */
	size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
	size -= sizeof(u32);

	/*
	 * Impossible, but be paranoid with the future
	 * How to put this check outside runtime?
	 */
	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
		"exit event has grown above perf buffer size"))
		return;

	rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
				sys_data->exit_event->event.type, regs, &rctx);
	if (!rec)
		return;

	rec->nr = syscall_nr;
	rec->ret = syscall_get_return_value(current, regs);

	head = this_cpu_ptr(sys_data->exit_event->perf_events);
	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
}

int perf_sysexit_enable(struct ftrace_event_call *call)
{
	int ret = 0;
	int num;

	num = ((struct syscall_metadata *)call->data)->syscall_nr;

	mutex_lock(&syscall_trace_lock);
	if (!sys_perf_refcount_exit)
		ret = register_trace_sys_exit(perf_syscall_exit, NULL);
	if (ret) {
		pr_info("event trace: Could not activate"
				"syscall exit trace point");
	} else {
		set_bit(num, enabled_perf_exit_syscalls);
		sys_perf_refcount_exit++;
	}
	mutex_unlock(&syscall_trace_lock);
	return ret;
}

void perf_sysexit_disable(struct ftrace_event_call *call)
{
	int num;

	num = ((struct syscall_metadata *)call->data)->syscall_nr;

	mutex_lock(&syscall_trace_lock);
	sys_perf_refcount_exit--;
	clear_bit(num, enabled_perf_exit_syscalls);
	if (!sys_perf_refcount_exit)
		unregister_trace_sys_exit(perf_syscall_exit, NULL);
	mutex_unlock(&syscall_trace_lock);
}

#endif /* CONFIG_PERF_EVENTS */

static int syscall_enter_register(struct ftrace_event_call *event,
				 enum trace_reg type)
{
	switch (type) {
	case TRACE_REG_REGISTER:
		return reg_event_syscall_enter(event);
	case TRACE_REG_UNREGISTER:
		unreg_event_syscall_enter(event);
		return 0;

#ifdef CONFIG_PERF_EVENTS
	case TRACE_REG_PERF_REGISTER:
		return perf_sysenter_enable(event);
	case TRACE_REG_PERF_UNREGISTER:
		perf_sysenter_disable(event);
		return 0;
#endif
	}
	return 0;
}

static int syscall_exit_register(struct ftrace_event_call *event,
				 enum trace_reg type)
{
	switch (type) {
	case TRACE_REG_REGISTER:
		return reg_event_syscall_exit(event);
	case TRACE_REG_UNREGISTER:
		unreg_event_syscall_exit(event);
		return 0;

#ifdef CONFIG_PERF_EVENTS
	case TRACE_REG_PERF_REGISTER:
		return perf_sysexit_enable(event);
	case TRACE_REG_PERF_UNREGISTER:
		perf_sysexit_disable(event);
		return 0;
#endif
	}
	return 0;
}
Commit	Line	Data
47788c58	1	#include <trace/syscall.h>
1c569f02	2	#include <trace/events/syscalls.h>
5a0e3ad6	3	#include <linux/slab.h>
ee08c6ec	4	#include <linux/kernel.h>
fb34a08c	5	#include <linux/ftrace.h>
cdd6c482	6	#include <linux/perf_event.h>
ee08c6ec FW	7	#include <asm/syscall.h>
	8
	9	#include "trace_output.h"
	10	#include "trace.h"
	11
5be71b61	12	static DEFINE_MUTEX(syscall_trace_lock);
fb34a08c JB	13	static int sys_refcount_enter;
fb34a08c JB	14	static int sys_refcount_exit;
57421dbb JB	15	static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls);
57421dbb JB	16	static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls);
ee08c6ec	17
2239291a SR	18	static int syscall_enter_register(struct ftrace_event_call *event,
	19	enum trace_reg type);
	20	static int syscall_exit_register(struct ftrace_event_call *event,
	21	enum trace_reg type);
	22
2e33af02 SR	23	static int syscall_enter_define_fields(struct ftrace_event_call *call);
	24	static int syscall_exit_define_fields(struct ftrace_event_call *call);
	25
c9642c49 LZ	26	/* All syscall exit events have the same fields */
	27	static LIST_HEAD(syscall_exit_fields);
	28
2e33af02 SR	29	static struct list_head *
	30	syscall_get_enter_fields(struct ftrace_event_call *call)
	31	{
	32	struct syscall_metadata *entry = call->data;
	33
	34	return &entry->enter_fields;
	35	}
	36
	37	static struct list_head *
	38	syscall_get_exit_fields(struct ftrace_event_call *call)
	39	{
c9642c49	40	return &syscall_exit_fields;
2e33af02 SR	41	}
2e33af02 SR	42
80decc70 SR	43	struct trace_event_functions enter_syscall_print_funcs = {
	44	.trace = print_syscall_enter,
	45	};
	46
	47	struct trace_event_functions exit_syscall_print_funcs = {
	48	.trace = print_syscall_exit,
	49	};
	50
2239291a SR	51	struct ftrace_event_class event_class_syscall_enter = {
2239291a SR	52	.system = "syscalls",
2e33af02 SR	53	.reg = syscall_enter_register,
	54	.define_fields = syscall_enter_define_fields,
	55	.get_fields = syscall_get_enter_fields,
0405ab80	56	.raw_init = init_syscall_trace,
2239291a SR	57	};
	58
	59	struct ftrace_event_class event_class_syscall_exit = {
	60	.system = "syscalls",
2e33af02 SR	61	.reg = syscall_exit_register,
	62	.define_fields = syscall_exit_define_fields,
	63	.get_fields = syscall_get_exit_fields,
0405ab80	64	.raw_init = init_syscall_trace,
8f082018 SR	65	};
8f082018 SR	66
c44fc770 FW	67	extern unsigned long __start_syscalls_metadata[];
	68	extern unsigned long __stop_syscalls_metadata[];
	69
	70	static struct syscall_metadata **syscalls_metadata;
	71
	72	static struct syscall_metadata *find_syscall_meta(unsigned long syscall)
	73	{
	74	struct syscall_metadata *start;
	75	struct syscall_metadata *stop;
	76	char str[KSYM_SYMBOL_LEN];
	77
	78
	79	start = (struct syscall_metadata *)__start_syscalls_metadata;
	80	stop = (struct syscall_metadata *)__stop_syscalls_metadata;
	81	kallsyms_lookup(syscall, NULL, NULL, NULL, str);
	82
	83	for ( ; start < stop; start++) {
	84	/*
	85	* Only compare after the "sys" prefix. Archs that use
	86	* syscall wrappers may have syscalls symbols aliases prefixed
	87	* with "SyS" instead of "sys", leading to an unwanted
	88	* mismatch.
	89	*/
	90	if (start->name && !strcmp(start->name + 3, str + 3))
	91	return start;
	92	}
	93	return NULL;
	94	}
	95
	96	static struct syscall_metadata *syscall_nr_to_meta(int nr)
	97	{
	98	if (!syscalls_metadata \|\| nr >= NR_syscalls \|\| nr < 0)
	99	return NULL;
	100
	101	return syscalls_metadata[nr];
	102	}
	103
bed1ffca	104	enum print_line_t
a9a57763 SR	105	print_syscall_enter(struct trace_iterator *iter, int flags,
a9a57763 SR	106	struct trace_event *event)
bed1ffca FW	107	{
	108	struct trace_seq *s = &iter->seq;
	109	struct trace_entry *ent = iter->ent;
	110	struct syscall_trace_enter *trace;
	111	struct syscall_metadata *entry;
	112	int i, ret, syscall;
	113
64c12e04	114	trace = (typeof(trace))ent;
bed1ffca	115	syscall = trace->nr;
bed1ffca	116	entry = syscall_nr_to_meta(syscall);
64c12e04	117
bed1ffca FW	118	if (!entry)
	119	goto end;
	120
32c0edae	121	if (entry->enter_event->event.type != ent->type) {
64c12e04 JB	122	WARN_ON_ONCE(1);
	123	goto end;
	124	}
	125
bed1ffca FW	126	ret = trace_seq_printf(s, "%s(", entry->name);
	127	if (!ret)
	128	return TRACE_TYPE_PARTIAL_LINE;
	129
	130	for (i = 0; i < entry->nb_args; i++) {
	131	/* parameter types */
ba8b3a40	132	if (trace_flags & TRACE_ITER_VERBOSE) {
bed1ffca FW	133	ret = trace_seq_printf(s, "%s ", entry->types[i]);
	134	if (!ret)
	135	return TRACE_TYPE_PARTIAL_LINE;
	136	}
	137	/* parameter values */
4539f077	138	ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i],
bed1ffca	139	trace->args[i],
4539f077	140	i == entry->nb_args - 1 ? "" : ", ");
bed1ffca FW	141	if (!ret)
	142	return TRACE_TYPE_PARTIAL_LINE;
	143	}
	144
4539f077 LZ	145	ret = trace_seq_putc(s, ')');
	146	if (!ret)
	147	return TRACE_TYPE_PARTIAL_LINE;
	148
bed1ffca	149	end:
4539f077 LZ	150	ret = trace_seq_putc(s, '\n');
	151	if (!ret)
	152	return TRACE_TYPE_PARTIAL_LINE;
	153
bed1ffca FW	154	return TRACE_TYPE_HANDLED;
	155	}
	156
	157	enum print_line_t
a9a57763 SR	158	print_syscall_exit(struct trace_iterator *iter, int flags,
a9a57763 SR	159	struct trace_event *event)
bed1ffca FW	160	{
	161	struct trace_seq *s = &iter->seq;
	162	struct trace_entry *ent = iter->ent;
	163	struct syscall_trace_exit *trace;
	164	int syscall;
	165	struct syscall_metadata *entry;
	166	int ret;
	167
64c12e04	168	trace = (typeof(trace))ent;
bed1ffca	169	syscall = trace->nr;
bed1ffca	170	entry = syscall_nr_to_meta(syscall);
64c12e04	171
bed1ffca FW	172	if (!entry) {
	173	trace_seq_printf(s, "\n");
	174	return TRACE_TYPE_HANDLED;
	175	}
	176
32c0edae	177	if (entry->exit_event->event.type != ent->type) {
64c12e04 JB	178	WARN_ON_ONCE(1);
	179	return TRACE_TYPE_UNHANDLED;
	180	}
	181
bed1ffca FW	182	ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name,
	183	trace->ret);
	184	if (!ret)
	185	return TRACE_TYPE_PARTIAL_LINE;
	186
	187	return TRACE_TYPE_HANDLED;
	188	}
	189
e6971969 LZ	190	extern char *__bad_type_size(void);
	191
	192	#define SYSCALL_FIELD(type, name) \
	193	sizeof(type) != sizeof(trace.name) ? \
	194	__bad_type_size() : \
26a50744 TZ	195	#type, #name, offsetof(typeof(trace), name), \
26a50744 TZ	196	sizeof(trace.name), is_signed_type(type)
e6971969	197
50307a45 LJ	198	static
	199	int __set_enter_print_fmt(struct syscall_metadata entry, char buf, int len)
	200	{
	201	int i;
	202	int pos = 0;
	203
	204	/* When len=0, we just calculate the needed length */
	205	#define LEN_OR_ZERO (len ? len - pos : 0)
	206
	207	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
	208	for (i = 0; i < entry->nb_args; i++) {
	209	pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s",
	210	entry->args[i], sizeof(unsigned long),
	211	i == entry->nb_args - 1 ? "" : ", ");
	212	}
	213	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
	214
	215	for (i = 0; i < entry->nb_args; i++) {
	216	pos += snprintf(buf + pos, LEN_OR_ZERO,
	217	", ((unsigned long)(REC->%s))", entry->args[i]);
	218	}
	219
	220	#undef LEN_OR_ZERO
	221
	222	/* return the length of print_fmt */
	223	return pos;
	224	}
	225
	226	static int set_syscall_print_fmt(struct ftrace_event_call *call)
	227	{
	228	char *print_fmt;
	229	int len;
	230	struct syscall_metadata *entry = call->data;
	231
	232	if (entry->enter_event != call) {
	233	call->print_fmt = "\"0x%lx\", REC->ret";
	234	return 0;
	235	}
	236
	237	/* First: called with 0 length to calculate the needed length */
	238	len = __set_enter_print_fmt(entry, NULL, 0);
	239
	240	print_fmt = kmalloc(len + 1, GFP_KERNEL);
	241	if (!print_fmt)
	242	return -ENOMEM;
	243
	244	/* Second: actually write the @print_fmt */
	245	__set_enter_print_fmt(entry, print_fmt, len + 1);
	246	call->print_fmt = print_fmt;
	247
	248	return 0;
	249	}
	250
	251	static void free_syscall_print_fmt(struct ftrace_event_call *call)
	252	{
	253	struct syscall_metadata *entry = call->data;
	254
	255	if (entry->enter_event == call)
	256	kfree(call->print_fmt);
	257	}
	258
2e33af02	259	static int syscall_enter_define_fields(struct ftrace_event_call *call)
540b7b8d LZ	260	{
540b7b8d LZ	261	struct syscall_trace_enter trace;
31c16b13	262	struct syscall_metadata *meta = call->data;
540b7b8d	263	int ret;
540b7b8d LZ	264	int i;
	265	int offset = offsetof(typeof(trace), args);
	266
0f1ef51d LJ	267	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
	268	if (ret)
	269	return ret;
	270
540b7b8d	271	for (i = 0; i < meta->nb_args; i++) {
aeaeae11 FW	272	ret = trace_define_field(call, meta->types[i],
aeaeae11 FW	273	meta->args[i], offset,
43b51ead LZ	274	sizeof(unsigned long), 0,
43b51ead LZ	275	FILTER_OTHER);
540b7b8d LZ	276	offset += sizeof(unsigned long);
	277	}
	278
	279	return ret;
	280	}
	281
2e33af02	282	static int syscall_exit_define_fields(struct ftrace_event_call *call)
540b7b8d LZ	283	{
	284	struct syscall_trace_exit trace;
	285	int ret;
	286
0f1ef51d LJ	287	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
	288	if (ret)
	289	return ret;
	290
26a50744	291	ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
43b51ead	292	FILTER_OTHER);
540b7b8d LZ	293
	294	return ret;
	295	}
	296
38516ab5	297	void ftrace_syscall_enter(void ignore, struct pt_regs regs, long id)
ee08c6ec	298	{
bed1ffca FW	299	struct syscall_trace_enter *entry;
	300	struct syscall_metadata *sys_data;
	301	struct ring_buffer_event *event;
e77405ad	302	struct ring_buffer *buffer;
bed1ffca	303	int size;
ee08c6ec FW	304	int syscall_nr;
	305
	306	syscall_nr = syscall_get_nr(current, regs);
cd0980fc HB	307	if (syscall_nr < 0)
cd0980fc HB	308	return;
fb34a08c JB	309	if (!test_bit(syscall_nr, enabled_enter_syscalls))
fb34a08c JB	310	return;
ee08c6ec	311
bed1ffca FW	312	sys_data = syscall_nr_to_meta(syscall_nr);
	313	if (!sys_data)
	314	return;
	315
	316	size = sizeof(entry) + sizeof(unsigned long) sys_data->nb_args;
	317
fcc19438	318	event = trace_current_buffer_lock_reserve(&buffer,
32c0edae	319	sys_data->enter_event->event.type, size, 0, 0);
bed1ffca FW	320	if (!event)
	321	return;
	322
	323	entry = ring_buffer_event_data(event);
	324	entry->nr = syscall_nr;
	325	syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args);
	326
e77405ad SR	327	if (!filter_current_check_discard(buffer, sys_data->enter_event,
	328	entry, event))
	329	trace_current_buffer_unlock_commit(buffer, event, 0, 0);
ee08c6ec FW	330	}
ee08c6ec FW	331
38516ab5	332	void ftrace_syscall_exit(void ignore, struct pt_regs regs, long ret)
ee08c6ec	333	{
bed1ffca FW	334	struct syscall_trace_exit *entry;
	335	struct syscall_metadata *sys_data;
	336	struct ring_buffer_event *event;
e77405ad	337	struct ring_buffer *buffer;
ee08c6ec FW	338	int syscall_nr;
	339
	340	syscall_nr = syscall_get_nr(current, regs);
cd0980fc HB	341	if (syscall_nr < 0)
cd0980fc HB	342	return;
fb34a08c JB	343	if (!test_bit(syscall_nr, enabled_exit_syscalls))
fb34a08c JB	344	return;
ee08c6ec	345
bed1ffca FW	346	sys_data = syscall_nr_to_meta(syscall_nr);
	347	if (!sys_data)
	348	return;
	349
fcc19438	350	event = trace_current_buffer_lock_reserve(&buffer,
32c0edae	351	sys_data->exit_event->event.type, sizeof(*entry), 0, 0);
bed1ffca FW	352	if (!event)
	353	return;
	354
	355	entry = ring_buffer_event_data(event);
	356	entry->nr = syscall_nr;
	357	entry->ret = syscall_get_return_value(current, regs);
	358
e77405ad SR	359	if (!filter_current_check_discard(buffer, sys_data->exit_event,
	360	entry, event))
	361	trace_current_buffer_unlock_commit(buffer, event, 0, 0);
ee08c6ec FW	362	}
ee08c6ec FW	363
bd1a5c84	364	int reg_event_syscall_enter(struct ftrace_event_call *call)
ee08c6ec	365	{
fb34a08c JB	366	int ret = 0;
fb34a08c JB	367	int num;
fb34a08c	368
c252f657	369	num = ((struct syscall_metadata *)call->data)->syscall_nr;
57421dbb	370	if (num < 0 \|\| num >= NR_syscalls)
fb34a08c JB	371	return -ENOSYS;
	372	mutex_lock(&syscall_trace_lock);
	373	if (!sys_refcount_enter)
38516ab5	374	ret = register_trace_sys_enter(ftrace_syscall_enter, NULL);
3b8e4273	375	if (!ret) {
fb34a08c JB	376	set_bit(num, enabled_enter_syscalls);
	377	sys_refcount_enter++;
	378	}
	379	mutex_unlock(&syscall_trace_lock);
	380	return ret;
ee08c6ec FW	381	}
ee08c6ec FW	382
bd1a5c84	383	void unreg_event_syscall_enter(struct ftrace_event_call *call)
ee08c6ec	384	{
fb34a08c	385	int num;
ee08c6ec	386
c252f657	387	num = ((struct syscall_metadata *)call->data)->syscall_nr;
57421dbb	388	if (num < 0 \|\| num >= NR_syscalls)
fb34a08c JB	389	return;
	390	mutex_lock(&syscall_trace_lock);
	391	sys_refcount_enter--;
	392	clear_bit(num, enabled_enter_syscalls);
	393	if (!sys_refcount_enter)
38516ab5	394	unregister_trace_sys_enter(ftrace_syscall_enter, NULL);
fb34a08c JB	395	mutex_unlock(&syscall_trace_lock);
fb34a08c JB	396	}
ee08c6ec	397
bd1a5c84	398	int reg_event_syscall_exit(struct ftrace_event_call *call)
ee08c6ec	399	{
fb34a08c JB	400	int ret = 0;
fb34a08c JB	401	int num;
fb34a08c	402
c252f657	403	num = ((struct syscall_metadata *)call->data)->syscall_nr;
57421dbb	404	if (num < 0 \|\| num >= NR_syscalls)
fb34a08c JB	405	return -ENOSYS;
	406	mutex_lock(&syscall_trace_lock);
	407	if (!sys_refcount_exit)
38516ab5	408	ret = register_trace_sys_exit(ftrace_syscall_exit, NULL);
3b8e4273	409	if (!ret) {
fb34a08c JB	410	set_bit(num, enabled_exit_syscalls);
fb34a08c JB	411	sys_refcount_exit++;
ee08c6ec	412	}
fb34a08c JB	413	mutex_unlock(&syscall_trace_lock);
	414	return ret;
	415	}
ee08c6ec	416
bd1a5c84	417	void unreg_event_syscall_exit(struct ftrace_event_call *call)
fb34a08c JB	418	{
fb34a08c JB	419	int num;
ee08c6ec	420
c252f657	421	num = ((struct syscall_metadata *)call->data)->syscall_nr;
57421dbb	422	if (num < 0 \|\| num >= NR_syscalls)
fb34a08c JB	423	return;
	424	mutex_lock(&syscall_trace_lock);
	425	sys_refcount_exit--;
	426	clear_bit(num, enabled_exit_syscalls);
	427	if (!sys_refcount_exit)
38516ab5	428	unregister_trace_sys_exit(ftrace_syscall_exit, NULL);
fb34a08c	429	mutex_unlock(&syscall_trace_lock);
ee08c6ec	430	}
fb34a08c	431
a1301da0 LJ	432	int init_syscall_trace(struct ftrace_event_call *call)
	433	{
	434	int id;
	435
50307a45 LJ	436	if (set_syscall_print_fmt(call) < 0)
	437	return -ENOMEM;
	438
c7ef3a90 SR	439	id = trace_event_raw_init(call);
	440
	441	if (id < 0) {
50307a45	442	free_syscall_print_fmt(call);
c7ef3a90	443	return id;
50307a45	444	}
c7ef3a90 SR	445
c7ef3a90 SR	446	return id;
a1301da0 LJ	447	}
a1301da0 LJ	448
e7b8e675 MF	449	unsigned long __init arch_syscall_addr(int nr)
	450	{
	451	return (unsigned long)sys_call_table[nr];
	452	}
	453
c44fc770 FW	454	int __init init_ftrace_syscalls(void)
	455	{
	456	struct syscall_metadata *meta;
	457	unsigned long addr;
	458	int i;
	459
	460	syscalls_metadata = kzalloc(sizeof(syscalls_metadata)
	461	NR_syscalls, GFP_KERNEL);
	462	if (!syscalls_metadata) {
	463	WARN_ON(1);
	464	return -ENOMEM;
	465	}
	466
	467	for (i = 0; i < NR_syscalls; i++) {
	468	addr = arch_syscall_addr(i);
	469	meta = find_syscall_meta(addr);
c252f657 LJ	470	if (!meta)
	471	continue;
	472
	473	meta->syscall_nr = i;
c44fc770 FW	474	syscalls_metadata[i] = meta;
	475	}
	476
	477	return 0;
	478	}
	479	core_initcall(init_ftrace_syscalls);
	480
07b139c8	481	#ifdef CONFIG_PERF_EVENTS
19007a67	482
97d5a220 FW	483	static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls);
	484	static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls);
	485	static int sys_perf_refcount_enter;
	486	static int sys_perf_refcount_exit;
f4b5ffcc	487
38516ab5	488	static void perf_syscall_enter(void ignore, struct pt_regs regs, long id)
f4b5ffcc JB	489	{
f4b5ffcc JB	490	struct syscall_metadata *sys_data;
20ab4425	491	struct syscall_trace_enter *rec;
1c024eca	492	struct hlist_head *head;
f4b5ffcc	493	int syscall_nr;
4ed7c92d	494	int rctx;
19007a67	495	int size;
f4b5ffcc JB	496
f4b5ffcc JB	497	syscall_nr = syscall_get_nr(current, regs);
97d5a220	498	if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
f4b5ffcc JB	499	return;
	500
	501	sys_data = syscall_nr_to_meta(syscall_nr);
	502	if (!sys_data)
	503	return;
	504
19007a67 FW	505	/* get the size after alignment with the u32 buffer size field */
	506	size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
	507	size = ALIGN(size + sizeof(u32), sizeof(u64));
	508	size -= sizeof(u32);
	509
97d5a220 FW	510	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
97d5a220 FW	511	"perf buffer not large enough"))
20ab4425 FW	512	return;
20ab4425 FW	513
97d5a220	514	rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
ff5f149b	515	sys_data->enter_event->event.type, regs, &rctx);
430ad5a6 XG	516	if (!rec)
430ad5a6 XG	517	return;
20ab4425	518
20ab4425 FW	519	rec->nr = syscall_nr;
	520	syscall_get_arguments(current, regs, 0, sys_data->nb_args,
	521	(unsigned long *)&rec->args);
1c024eca	522
3771f077	523	head = this_cpu_ptr(sys_data->enter_event->perf_events);
1c024eca	524	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
f4b5ffcc JB	525	}
f4b5ffcc JB	526
97d5a220	527	int perf_sysenter_enable(struct ftrace_event_call *call)
f4b5ffcc JB	528	{
	529	int ret = 0;
	530	int num;
	531
3bbe84e9	532	num = ((struct syscall_metadata *)call->data)->syscall_nr;
f4b5ffcc JB	533
f4b5ffcc JB	534	mutex_lock(&syscall_trace_lock);
97d5a220	535	if (!sys_perf_refcount_enter)
38516ab5	536	ret = register_trace_sys_enter(perf_syscall_enter, NULL);
f4b5ffcc JB	537	if (ret) {
	538	pr_info("event trace: Could not activate"
	539	"syscall entry trace point");
	540	} else {
97d5a220 FW	541	set_bit(num, enabled_perf_enter_syscalls);
97d5a220 FW	542	sys_perf_refcount_enter++;
f4b5ffcc JB	543	}
	544	mutex_unlock(&syscall_trace_lock);
	545	return ret;
	546	}
	547
97d5a220	548	void perf_sysenter_disable(struct ftrace_event_call *call)
f4b5ffcc JB	549	{
	550	int num;
	551
3bbe84e9	552	num = ((struct syscall_metadata *)call->data)->syscall_nr;
f4b5ffcc JB	553
f4b5ffcc JB	554	mutex_lock(&syscall_trace_lock);
97d5a220 FW	555	sys_perf_refcount_enter--;
	556	clear_bit(num, enabled_perf_enter_syscalls);
	557	if (!sys_perf_refcount_enter)
38516ab5	558	unregister_trace_sys_enter(perf_syscall_enter, NULL);
f4b5ffcc JB	559	mutex_unlock(&syscall_trace_lock);
	560	}
	561
38516ab5	562	static void perf_syscall_exit(void ignore, struct pt_regs regs, long ret)
f4b5ffcc JB	563	{
f4b5ffcc JB	564	struct syscall_metadata *sys_data;
20ab4425	565	struct syscall_trace_exit *rec;
1c024eca	566	struct hlist_head *head;
f4b5ffcc	567	int syscall_nr;
4ed7c92d	568	int rctx;
20ab4425	569	int size;
f4b5ffcc JB	570
f4b5ffcc JB	571	syscall_nr = syscall_get_nr(current, regs);
97d5a220	572	if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
f4b5ffcc JB	573	return;
	574
	575	sys_data = syscall_nr_to_meta(syscall_nr);
	576	if (!sys_data)
	577	return;
	578
20ab4425 FW	579	/* We can probably do that at build time */
	580	size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
	581	size -= sizeof(u32);
19007a67	582
20ab4425 FW	583	/*
	584	* Impossible, but be paranoid with the future
	585	* How to put this check outside runtime?
	586	*/
97d5a220 FW	587	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
97d5a220 FW	588	"exit event has grown above perf buffer size"))
20ab4425 FW	589	return;
20ab4425 FW	590
97d5a220	591	rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
ff5f149b	592	sys_data->exit_event->event.type, regs, &rctx);
430ad5a6 XG	593	if (!rec)
430ad5a6 XG	594	return;
20ab4425	595
20ab4425 FW	596	rec->nr = syscall_nr;
	597	rec->ret = syscall_get_return_value(current, regs);
	598
3771f077	599	head = this_cpu_ptr(sys_data->exit_event->perf_events);
1c024eca	600	perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
f4b5ffcc JB	601	}
f4b5ffcc JB	602
97d5a220	603	int perf_sysexit_enable(struct ftrace_event_call *call)
f4b5ffcc JB	604	{
	605	int ret = 0;
	606	int num;
	607
3bbe84e9	608	num = ((struct syscall_metadata *)call->data)->syscall_nr;
f4b5ffcc JB	609
f4b5ffcc JB	610	mutex_lock(&syscall_trace_lock);
97d5a220	611	if (!sys_perf_refcount_exit)
38516ab5	612	ret = register_trace_sys_exit(perf_syscall_exit, NULL);
f4b5ffcc JB	613	if (ret) {
f4b5ffcc JB	614	pr_info("event trace: Could not activate"
6574658b	615	"syscall exit trace point");
f4b5ffcc	616	} else {
97d5a220 FW	617	set_bit(num, enabled_perf_exit_syscalls);
97d5a220 FW	618	sys_perf_refcount_exit++;
f4b5ffcc JB	619	}
	620	mutex_unlock(&syscall_trace_lock);
	621	return ret;
	622	}
	623
97d5a220	624	void perf_sysexit_disable(struct ftrace_event_call *call)
f4b5ffcc JB	625	{
	626	int num;
	627
3bbe84e9	628	num = ((struct syscall_metadata *)call->data)->syscall_nr;
f4b5ffcc JB	629
f4b5ffcc JB	630	mutex_lock(&syscall_trace_lock);
97d5a220 FW	631	sys_perf_refcount_exit--;
	632	clear_bit(num, enabled_perf_exit_syscalls);
	633	if (!sys_perf_refcount_exit)
38516ab5	634	unregister_trace_sys_exit(perf_syscall_exit, NULL);
f4b5ffcc JB	635	mutex_unlock(&syscall_trace_lock);
	636	}
	637
07b139c8	638	#endif /* CONFIG_PERF_EVENTS */
f4b5ffcc	639
2239291a SR	640	static int syscall_enter_register(struct ftrace_event_call *event,
	641	enum trace_reg type)
	642	{
	643	switch (type) {
	644	case TRACE_REG_REGISTER:
	645	return reg_event_syscall_enter(event);
	646	case TRACE_REG_UNREGISTER:
	647	unreg_event_syscall_enter(event);
	648	return 0;
	649
	650	#ifdef CONFIG_PERF_EVENTS
	651	case TRACE_REG_PERF_REGISTER:
	652	return perf_sysenter_enable(event);
	653	case TRACE_REG_PERF_UNREGISTER:
	654	perf_sysenter_disable(event);
	655	return 0;
	656	#endif
	657	}
	658	return 0;
	659	}
	660
	661	static int syscall_exit_register(struct ftrace_event_call *event,
	662	enum trace_reg type)
	663	{
	664	switch (type) {
	665	case TRACE_REG_REGISTER:
	666	return reg_event_syscall_exit(event);
	667	case TRACE_REG_UNREGISTER:
	668	unreg_event_syscall_exit(event);
	669	return 0;
	670
	671	#ifdef CONFIG_PERF_EVENTS
	672	case TRACE_REG_PERF_REGISTER:
	673	return perf_sysexit_enable(event);
	674	case TRACE_REG_PERF_UNREGISTER:
	675	perf_sysexit_disable(event);
	676	return 0;
	677	#endif
	678	}
	679	return 0;
	680	}