[lttng-modules.git] / lttng-syscalls.c

/*
 * lttng-syscalls.c
 *
 * Copyright 2010-2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * LTTng syscall probes.
 *
 * Dual LGPL v2.1/GPL v2 license.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/compat.h>
#include <asm/ptrace.h>
#include <asm/syscall.h>

#include "ltt-events.h"

#ifndef CONFIG_COMPAT
static inline int is_compat_task(void)
{
	return 0;
}
#endif

void syscall_entry_probe(void *__data, struct pt_regs *regs, long id);

/*
 * Take care of NOARGS not supported by mainline.
 */
#define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print)
#define DEFINE_EVENT_NOARGS(template, name)
#define TRACE_EVENT_NOARGS(name, struct, assign, print)

/*
 * Create LTTng tracepoint probes.
 */
#define LTTNG_PACKAGE_BUILD
#define CREATE_TRACE_POINTS
#define TP_MODULE_OVERRIDE
#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers

/* Hijack probe callback for system calls */
#define TP_PROBE_CB(_template)		&syscall_entry_probe
#include "instrumentation/syscalls/headers/syscalls_integers.h"
#include "instrumentation/syscalls/headers/syscalls_pointers.h"
#undef TP_PROBE_CB

#include "instrumentation/syscalls/headers/syscalls_unknown.h"

#undef TP_MODULE_OVERRIDE
#undef LTTNG_PACKAGE_BUILD
#undef CREATE_TRACE_POINTS

#undef TRACE_SYSCALL_TABLE
#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs)	\
	[ _nr ] = {						\
		.func = __event_probe__##_template,		\
		.nrargs = (_nrargs),				\
		.fields = __event_fields___##_template,		\
		.desc = &__event_desc___##_name,		\
	},

#define CREATE_SYSCALL_TABLE

static const struct trace_syscall_entry sc_table[] = {
#include "instrumentation/syscalls/headers/syscalls_integers.h"
#include "instrumentation/syscalls/headers/syscalls_pointers.h"
};

#undef CREATE_SYSCALL_TABLE

//extern const struct trace_syscall_entry compat_sc_table[];
//extern const size_t compat_sc_table_len;
//temp disable
static const struct trace_syscall_entry compat_sc_table[] = { };
static const size_t compat_sc_table_len;

static void syscall_entry_unknown(struct ltt_event *event,
	struct pt_regs *regs, unsigned int id)
{
	unsigned long args[UNKNOWN_SYSCALL_NRARGS];

	syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
	__event_probe__sys_unknown(event, id, args);
}

void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
{
	struct ltt_channel *chan = __data;
	struct ltt_event *event, *unknown_event;
	const struct trace_syscall_entry *table, *entry;
	size_t table_len;

	if (unlikely(is_compat_task())) {
		table = compat_sc_table;
		table_len = compat_sc_table_len;
		unknown_event = chan->sc_compat_unknown;
	} else {
		table = sc_table;
		table_len = ARRAY_SIZE(sc_table);
		unknown_event = chan->sc_unknown;
	}
	if (unlikely(id >= table_len)) {
		syscall_entry_unknown(unknown_event, regs, id);
		return;
	}
	if (unlikely(is_compat_task()))
		event = chan->compat_sc_table[id];
	else
		event = chan->sc_table[id];
	if (unlikely(!event)) {
		syscall_entry_unknown(unknown_event, regs, id);
		return;
	}
	entry = &table[id];
	WARN_ON_ONCE(!entry);

	switch (entry->nrargs) {
	case 0:
	{
		void (*fptr)(void *__data) = entry->func;

		fptr(event);
		break;
	}
	case 1:
	{
		void (*fptr)(void *__data, unsigned long arg0) = entry->func;
		unsigned long args[1];

		syscall_get_arguments(current, regs, 0, entry->nrargs, args);
		fptr(event, args[0]);
		break;
	}
	case 2:
	{
		void (*fptr)(void *__data,
			unsigned long arg0,
			unsigned long arg1) = entry->func;
		unsigned long args[2];

		syscall_get_arguments(current, regs, 0, entry->nrargs, args);
		fptr(event, args[0], args[1]);
		break;
	}
	case 3:
	{
		void (*fptr)(void *__data,
			unsigned long arg0,
			unsigned long arg1,
			unsigned long arg2) = entry->func;
		unsigned long args[3];

		syscall_get_arguments(current, regs, 0, entry->nrargs, args);
		fptr(event, args[0], args[1], args[2]);
		break;
	}
	case 4:
	{
		void (*fptr)(void *__data,
			unsigned long arg0,
			unsigned long arg1,
			unsigned long arg2,
			unsigned long arg3) = entry->func;
		unsigned long args[4];

		syscall_get_arguments(current, regs, 0, entry->nrargs, args);
		fptr(event, args[0], args[1], args[2], args[3]);
		break;
	}
	case 5:
	{
		void (*fptr)(void *__data,
			unsigned long arg0,
			unsigned long arg1,
			unsigned long arg2,
			unsigned long arg3,
			unsigned long arg4) = entry->func;
		unsigned long args[5];

		syscall_get_arguments(current, regs, 0, entry->nrargs, args);
		fptr(event, args[0], args[1], args[2], args[3], args[4]);
		break;
	}
	case 6:
	{
		void (*fptr)(void *__data,
			unsigned long arg0,
			unsigned long arg1,
			unsigned long arg2,
			unsigned long arg3,
			unsigned long arg4,
			unsigned long arg5) = entry->func;
		unsigned long args[6];

		syscall_get_arguments(current, regs, 0, entry->nrargs, args);
		fptr(event, args[0], args[1], args[2],
			args[3], args[4], args[5]);
		break;
	}
	default:
		break;
	}
}

static
int fill_table(const struct trace_syscall_entry *table, size_t table_len,
	struct ltt_event **chan_table, struct ltt_channel *chan, void *filter)
{
	unsigned int i;

	/* Allocate events for each syscall, insert into table */
	for (i = 0; i < table_len; i++) {
		struct lttng_kernel_event ev;
		const struct lttng_event_desc *desc = table[i].desc;

		if (!desc) {
			/* Unknown syscall */
			continue;
		}
		/*
		 * Skip those already populated by previous failed
		 * register for this channel.
		 */
		if (chan_table[i])
			continue;
		memset(&ev, 0, sizeof(ev));
		strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
		ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
		ev.instrumentation = LTTNG_KERNEL_NOOP;
		chan_table[i] = ltt_event_create(chan, &ev, filter,
						desc);
		if (!chan_table[i]) {
			/*
			 * If something goes wrong in event registration
			 * after the first one, we have no choice but to
			 * leave the previous events in there, until
			 * deleted by session teardown.
			 */
			return -EINVAL;
		}
	}
	return 0;
}

int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
{
	int ret;

	wrapper_vmalloc_sync_all();

	if (!chan->sc_table) {
		/* create syscall table mapping syscall to events */
		chan->sc_table = kzalloc(sizeof(struct ltt_event *)
					* ARRAY_SIZE(sc_table), GFP_KERNEL);
		if (!chan->sc_table)
			return -ENOMEM;
	}

#ifdef CONFIG_COMPAT
	if (!chan->compat_sc_table) {
		/* create syscall table mapping compat syscall to events */
		chan->compat_sc_table = kzalloc(sizeof(struct ltt_event *)
					* compat_sc_table_len, GFP_KERNEL);
		if (!chan->compat_sc_table)
			return -ENOMEM;
	}
#endif
	if (!chan->sc_unknown) {
		struct lttng_kernel_event ev;
		const struct lttng_event_desc *desc =
			&__event_desc___sys_unknown;

		memset(&ev, 0, sizeof(ev));
		strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
		ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
		ev.instrumentation = LTTNG_KERNEL_NOOP;
		chan->sc_unknown = ltt_event_create(chan, &ev, filter,
						    desc);
		if (!chan->sc_unknown) {
			return -EINVAL;
		}
	}

	if (!chan->sc_compat_unknown) {
		struct lttng_kernel_event ev;
		const struct lttng_event_desc *desc =
			&__event_desc___compat_sys_unknown;

		memset(&ev, 0, sizeof(ev));
		strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
		ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
		ev.instrumentation = LTTNG_KERNEL_NOOP;
		chan->sc_compat_unknown = ltt_event_create(chan, &ev, filter,
							   desc);
		if (!chan->sc_compat_unknown) {
			return -EINVAL;
		}
	}

	if (!chan->sc_exit) {
		struct lttng_kernel_event ev;
		const struct lttng_event_desc *desc =
			&__event_desc___exit_syscall;

		memset(&ev, 0, sizeof(ev));
		strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
		ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
		ev.instrumentation = LTTNG_KERNEL_NOOP;
		chan->sc_exit = ltt_event_create(chan, &ev, filter,
						 desc);
		if (!chan->sc_exit) {
			return -EINVAL;
		}
	}

	ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
			chan->sc_table, chan, filter);
	if (ret)
		return ret;
#ifdef CONFIG_COMPAT
	ret = fill_table(compat_sc_table, compat_sc_table_len,
			chan->compat_sc_table, chan, filter);
	if (ret)
		return ret;
#endif
	ret = tracepoint_probe_register("sys_enter",
			(void *) syscall_entry_probe, chan);
	if (ret)
		return ret;
	/*
	 * We change the name of sys_exit tracepoint due to namespace
	 * conflict with sys_exit syscall entry.
	 */
	ret = tracepoint_probe_register("sys_exit",
			(void *) __event_probe__exit_syscall,
			chan->sc_exit);
	if (ret) {
		WARN_ON_ONCE(tracepoint_probe_unregister("sys_enter",
			(void *) syscall_entry_probe, chan));
	}
	return ret;
}

/*
 * Only called at session destruction.
 */
int lttng_syscalls_unregister(struct ltt_channel *chan)
{
	int ret;

	if (!chan->sc_table)
		return 0;
	ret = tracepoint_probe_unregister("sys_exit",
			(void *) __event_probe__exit_syscall,
			chan->sc_exit);
	if (ret)
		return ret;
	ret = tracepoint_probe_unregister("sys_enter",
			(void *) syscall_entry_probe, chan);
	if (ret)
		return ret;
	/* ltt_event destroy will be performed by ltt_session_destroy() */
	kfree(chan->sc_table);
#ifdef CONFIG_COMPAT
	kfree(chan->compat_sc_table);
#endif
	return 0;
}
Commit	Line	Data
259b6cb3 MD	1	/*
	2	* lttng-syscalls.c
	3	*
2faf7d1b	4	* Copyright 2010-2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
259b6cb3	5	*
2faf7d1b	6	* LTTng syscall probes.
259b6cb3 MD	7	*
	8	* Dual LGPL v2.1/GPL v2 license.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/slab.h>
6333ace3	13	#include <linux/compat.h>
259b6cb3 MD	14	#include <asm/ptrace.h>
	15	#include <asm/syscall.h>
	16
	17	#include "ltt-events.h"
	18
6333ace3 MD	19	#ifndef CONFIG_COMPAT
	20	static inline int is_compat_task(void)
	21	{
	22	return 0;
	23	}
	24	#endif
	25
2faf7d1b	26	void syscall_entry_probe(void __data, struct pt_regs regs, long id);
259b6cb3	27
f7bdf4db MD	28	/*
	29	* Take care of NOARGS not supported by mainline.
	30	*/
	31	#define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print)
	32	#define DEFINE_EVENT_NOARGS(template, name)
	33	#define TRACE_EVENT_NOARGS(name, struct, assign, print)
	34
259b6cb3 MD	35	/*
	36	* Create LTTng tracepoint probes.
	37	*/
	38	#define LTTNG_PACKAGE_BUILD
	39	#define CREATE_TRACE_POINTS
2f804c0a MD	40	#define TP_MODULE_OVERRIDE
2f804c0a MD	41	#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers
259b6cb3 MD	42
	43	/* Hijack probe callback for system calls */
	44	#define TP_PROBE_CB(_template) &syscall_entry_probe
177b3692 MD	45	#include "instrumentation/syscalls/headers/syscalls_integers.h"
177b3692 MD	46	#include "instrumentation/syscalls/headers/syscalls_pointers.h"
2f804c0a MD	47	#undef TP_PROBE_CB
2f804c0a MD	48
63728b02	49	#include "instrumentation/syscalls/headers/syscalls_unknown.h"
259b6cb3 MD	50
259b6cb3 MD	51	#undef TP_MODULE_OVERRIDE
259b6cb3 MD	52	#undef LTTNG_PACKAGE_BUILD
	53	#undef CREATE_TRACE_POINTS
	54
259b6cb3	55	#undef TRACE_SYSCALL_TABLE
f7bdf4db	56	#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
259b6cb3	57	[ _nr ] = { \
f7bdf4db	58	.func = __event_probe__##_template, \
259b6cb3	59	.nrargs = (_nrargs), \
f7bdf4db MD	60	.fields = __event_fields___##_template, \
f7bdf4db MD	61	.desc = &__event_desc___##_name, \
259b6cb3 MD	62	},
259b6cb3 MD	63
49c50022 MD	64	#define CREATE_SYSCALL_TABLE
	65
	66	static const struct trace_syscall_entry sc_table[] = {
177b3692 MD	67	#include "instrumentation/syscalls/headers/syscalls_integers.h"
177b3692 MD	68	#include "instrumentation/syscalls/headers/syscalls_pointers.h"
259b6cb3 MD	69	};
	70
	71	#undef CREATE_SYSCALL_TABLE
	72
2faf7d1b MD	73	//extern const struct trace_syscall_entry compat_sc_table[];
	74	//extern const size_t compat_sc_table_len;
	75	//temp disable
91a951f3	76	static const struct trace_syscall_entry compat_sc_table[] = { };
2faf7d1b MD	77	static const size_t compat_sc_table_len;
2faf7d1b MD	78
b76dc1a0	79	static void syscall_entry_unknown(struct ltt_event *event,
f405cfce MD	80	struct pt_regs *regs, unsigned int id)
	81	{
	82	unsigned long args[UNKNOWN_SYSCALL_NRARGS];
f405cfce	83
f405cfce MD	84	syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
	85	__event_probe__sys_unknown(event, id, args);
	86	}
	87
2faf7d1b	88	void syscall_entry_probe(void __data, struct pt_regs regs, long id)
259b6cb3	89	{
259b6cb3	90	struct ltt_channel *chan = __data;
49c50022 MD	91	struct ltt_event event, unknown_event;
	92	const struct trace_syscall_entry table, entry;
	93	size_t table_len;
259b6cb3	94
b76dc1a0	95	if (unlikely(is_compat_task())) {
49c50022	96	table = compat_sc_table;
2faf7d1b	97	table_len = compat_sc_table_len;
49c50022 MD	98	unknown_event = chan->sc_compat_unknown;
	99	} else {
	100	table = sc_table;
	101	table_len = ARRAY_SIZE(sc_table);
	102	unknown_event = chan->sc_unknown;
b76dc1a0	103	}
49c50022 MD	104	if (unlikely(id >= table_len)) {
49c50022 MD	105	syscall_entry_unknown(unknown_event, regs, id);
259b6cb3	106	return;
f405cfce	107	}
49c50022 MD	108	if (unlikely(is_compat_task()))
	109	event = chan->compat_sc_table[id];
	110	else
	111	event = chan->sc_table[id];
f405cfce	112	if (unlikely(!event)) {
49c50022	113	syscall_entry_unknown(unknown_event, regs, id);
f405cfce MD	114	return;
f405cfce MD	115	}
49c50022	116	entry = &table[id];
f405cfce	117	WARN_ON_ONCE(!entry);
259b6cb3 MD	118
	119	switch (entry->nrargs) {
	120	case 0:
	121	{
	122	void (fptr)(void __data) = entry->func;
	123
	124	fptr(event);
	125	break;
	126	}
	127	case 1:
	128	{
	129	void (fptr)(void __data, unsigned long arg0) = entry->func;
	130	unsigned long args[1];
	131
	132	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	133	fptr(event, args[0]);
	134	break;
	135	}
	136	case 2:
	137	{
	138	void (fptr)(void __data,
	139	unsigned long arg0,
	140	unsigned long arg1) = entry->func;
	141	unsigned long args[2];
	142
	143	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	144	fptr(event, args[0], args[1]);
	145	break;
	146	}
	147	case 3:
	148	{
	149	void (fptr)(void __data,
	150	unsigned long arg0,
	151	unsigned long arg1,
	152	unsigned long arg2) = entry->func;
	153	unsigned long args[3];
	154
	155	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	156	fptr(event, args[0], args[1], args[2]);
	157	break;
	158	}
	159	case 4:
	160	{
	161	void (fptr)(void __data,
	162	unsigned long arg0,
	163	unsigned long arg1,
	164	unsigned long arg2,
	165	unsigned long arg3) = entry->func;
	166	unsigned long args[4];
	167
	168	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	169	fptr(event, args[0], args[1], args[2], args[3]);
	170	break;
	171	}
	172	case 5:
	173	{
	174	void (fptr)(void __data,
	175	unsigned long arg0,
	176	unsigned long arg1,
	177	unsigned long arg2,
	178	unsigned long arg3,
	179	unsigned long arg4) = entry->func;
	180	unsigned long args[5];
	181
182	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
183	fptr(event, args[0], args[1], args[2], args[3], args[4]);
184	break;
185	}
186	case 6:
187	{
188	void (fptr)(void __data,
189	unsigned long arg0,
190	unsigned long arg1,
191	unsigned long arg2,
192	unsigned long arg3,
193	unsigned long arg4,
194	unsigned long arg5) = entry->func;
195	unsigned long args[6];
196
197	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
198	fptr(event, args[0], args[1], args[2],
199	args[3], args[4], args[5]);
200	break;
201	}
202	default:
203	break;
204	}
205	}
206
49c50022 MD	207	static
	208	int fill_table(const struct trace_syscall_entry *table, size_t table_len,
	209	struct ltt_event *chan_table, struct ltt_channel chan, void *filter)
259b6cb3 MD	210	{
259b6cb3 MD	211	unsigned int i;
49c50022 MD	212
	213	/* Allocate events for each syscall, insert into table */
	214	for (i = 0; i < table_len; i++) {
	215	struct lttng_kernel_event ev;
	216	const struct lttng_event_desc *desc = table[i].desc;
	217
	218	if (!desc) {
	219	/* Unknown syscall */
	220	continue;
	221	}
	222	/*
	223	* Skip those already populated by previous failed
	224	* register for this channel.
	225	*/
	226	if (chan_table[i])
	227	continue;
	228	memset(&ev, 0, sizeof(ev));
	229	strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
	230	ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
	231	ev.instrumentation = LTTNG_KERNEL_NOOP;
	232	chan_table[i] = ltt_event_create(chan, &ev, filter,
	233	desc);
	234	if (!chan_table[i]) {
	235	/*
	236	* If something goes wrong in event registration
	237	* after the first one, we have no choice but to
	238	* leave the previous events in there, until
	239	* deleted by session teardown.
	240	*/
	241	return -EINVAL;
	242	}
	243	}
	244	return 0;
	245	}
	246
	247	int lttng_syscalls_register(struct ltt_channel chan, void filter)
	248	{
259b6cb3 MD	249	int ret;
	250
	251	wrapper_vmalloc_sync_all();
259b6cb3 MD	252
	253	if (!chan->sc_table) {
	254	/* create syscall table mapping syscall to events */
	255	chan->sc_table = kzalloc(sizeof(struct ltt_event *)
	256	* ARRAY_SIZE(sc_table), GFP_KERNEL);
	257	if (!chan->sc_table)
	258	return -ENOMEM;
	259	}
	260
49c50022 MD	261	#ifdef CONFIG_COMPAT
	262	if (!chan->compat_sc_table) {
	263	/* create syscall table mapping compat syscall to events */
	264	chan->compat_sc_table = kzalloc(sizeof(struct ltt_event *)
2faf7d1b	265	* compat_sc_table_len, GFP_KERNEL);
49c50022 MD	266	if (!chan->compat_sc_table)
	267	return -ENOMEM;
	268	}
	269	#endif
f405cfce MD	270	if (!chan->sc_unknown) {
f405cfce MD	271	struct lttng_kernel_event ev;
f405cfce MD	272	const struct lttng_event_desc *desc =
f405cfce MD	273	&__event_desc___sys_unknown;
2f804c0a	274
f405cfce MD	275	memset(&ev, 0, sizeof(ev));
	276	strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
	277	ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
	278	ev.instrumentation = LTTNG_KERNEL_NOOP;
	279	chan->sc_unknown = ltt_event_create(chan, &ev, filter,
	280	desc);
	281	if (!chan->sc_unknown) {
	282	return -EINVAL;
	283	}
	284	}
	285
b76dc1a0 MD	286	if (!chan->sc_compat_unknown) {
	287	struct lttng_kernel_event ev;
	288	const struct lttng_event_desc *desc =
	289	&__event_desc___compat_sys_unknown;
	290
	291	memset(&ev, 0, sizeof(ev));
	292	strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
	293	ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
	294	ev.instrumentation = LTTNG_KERNEL_NOOP;
	295	chan->sc_compat_unknown = ltt_event_create(chan, &ev, filter,
	296	desc);
	297	if (!chan->sc_compat_unknown) {
	298	return -EINVAL;
	299	}
	300	}
	301
2f804c0a MD	302	if (!chan->sc_exit) {
	303	struct lttng_kernel_event ev;
	304	const struct lttng_event_desc *desc =
	305	&__event_desc___exit_syscall;
	306
	307	memset(&ev, 0, sizeof(ev));
	308	strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
	309	ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
	310	ev.instrumentation = LTTNG_KERNEL_NOOP;
	311	chan->sc_exit = ltt_event_create(chan, &ev, filter,
	312	desc);
	313	if (!chan->sc_exit) {
	314	return -EINVAL;
	315	}
	316	}
	317
49c50022 MD	318	ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
	319	chan->sc_table, chan, filter);
	320	if (ret)
	321	return ret;
	322	#ifdef CONFIG_COMPAT
2faf7d1b	323	ret = fill_table(compat_sc_table, compat_sc_table_len,
49c50022 MD	324	chan->compat_sc_table, chan, filter);
	325	if (ret)
	326	return ret;
	327	#endif
259b6cb3 MD	328	ret = tracepoint_probe_register("sys_enter",
259b6cb3 MD	329	(void *) syscall_entry_probe, chan);
63728b02 MD	330	if (ret)
	331	return ret;
	332	/*
	333	* We change the name of sys_exit tracepoint due to namespace
	334	* conflict with sys_exit syscall entry.
	335	*/
	336	ret = tracepoint_probe_register("sys_exit",
2c01ec07	337	(void *) __event_probe__exit_syscall,
2f804c0a	338	chan->sc_exit);
63728b02 MD	339	if (ret) {
	340	WARN_ON_ONCE(tracepoint_probe_unregister("sys_enter",
	341	(void *) syscall_entry_probe, chan));
	342	}
259b6cb3 MD	343	return ret;
	344	}
	345
	346	/*
	347	* Only called at session destruction.
	348	*/
	349	int lttng_syscalls_unregister(struct ltt_channel *chan)
	350	{
	351	int ret;
	352
	353	if (!chan->sc_table)
	354	return 0;
63728b02	355	ret = tracepoint_probe_unregister("sys_exit",
2c01ec07	356	(void *) __event_probe__exit_syscall,
2f804c0a	357	chan->sc_exit);
63728b02 MD	358	if (ret)
63728b02 MD	359	return ret;
259b6cb3 MD	360	ret = tracepoint_probe_unregister("sys_enter",
	361	(void *) syscall_entry_probe, chan);
	362	if (ret)
	363	return ret;
	364	/* ltt_event destroy will be performed by ltt_session_destroy() */
	365	kfree(chan->sc_table);
49c50022 MD	366	#ifdef CONFIG_COMPAT
	367	kfree(chan->compat_sc_table);
	368	#endif
259b6cb3 MD	369	return 0;
259b6cb3 MD	370	}