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

/*
 * lttng-syscalls.c
 *
 * LTTng syscall probes.
 *
 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

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

#include "wrapper/tracepoint.h"
#include "lttng-events.h"

#ifndef CONFIG_COMPAT
# ifndef is_compat_task
#  define is_compat_task()	(0)
# endif
#endif

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

/*
 * Forward declarations for old kernels.
 */
struct mmsghdr;
struct rlimit64;
struct oldold_utsname;
struct old_utsname;
struct sel_arg_struct;
struct mmap_arg_struct;
struct file_handle;

/*
 * 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_NOINIT
#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers

#define PARAMS(args...)	args

/* Hijack probe callback for system calls */
#undef TP_PROBE_CB
#define TP_PROBE_CB(_template)		&syscall_entry_probe
#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk)	\
	TRACE_EVENT(_name, PARAMS(_proto), PARAMS(_args),\
		PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk)	\
	DECLARE_EVENT_CLASS_NOARGS(_name, PARAMS(_struct), PARAMS(_assign),\
		PARAMS(_printk))
#define SC_DEFINE_EVENT_NOARGS(_template, _name)			\
	DEFINE_EVENT_NOARGS(_template, _name)
#undef TRACE_SYSTEM
#define TRACE_SYSTEM syscalls_integers
#include "instrumentation/syscalls/headers/syscalls_integers.h"
#undef TRACE_SYSTEM
#define TRACE_SYSTEM syscalls_pointers
#include "instrumentation/syscalls/headers/syscalls_pointers.h"
#undef TRACE_SYSTEM
#undef SC_TRACE_EVENT
#undef SC_DECLARE_EVENT_CLASS_NOARGS
#undef SC_DEFINE_EVENT_NOARGS

#define TRACE_SYSTEM syscalls_unknown
#include "instrumentation/syscalls/headers/syscalls_unknown.h"
#undef TRACE_SYSTEM

/* For compat syscalls */
#undef _TRACE_SYSCALLS_integers_H
#undef _TRACE_SYSCALLS_pointers_H

/* Hijack probe callback for system calls */
#undef TP_PROBE_CB
#define TP_PROBE_CB(_template)		&syscall_entry_probe
#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk)	\
	TRACE_EVENT(compat_##_name, PARAMS(_proto), PARAMS(_args),	\
		PARAMS(_struct), PARAMS(_assign),			\
		PARAMS(_printk))
#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
	DECLARE_EVENT_CLASS_NOARGS(compat_##_name, PARAMS(_struct),	\
		PARAMS(_assign), PARAMS(_printk))
#define SC_DEFINE_EVENT_NOARGS(_template, _name)			\
	DEFINE_EVENT_NOARGS(compat_##_template, compat_##_name)
#define TRACE_SYSTEM compat_syscalls_integers
#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
#undef TRACE_SYSTEM
#define TRACE_SYSTEM compat_syscalls_pointers
#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
#undef TRACE_SYSTEM
#undef SC_TRACE_EVENT
#undef SC_DECLARE_EVENT_CLASS_NOARGS
#undef SC_DEFINE_EVENT_NOARGS
#undef TP_PROBE_CB

#undef TP_MODULE_NOINIT
#undef LTTNG_PACKAGE_BUILD
#undef CREATE_TRACE_POINTS

struct trace_syscall_entry {
	void *func;
	const struct lttng_event_desc *desc;
	const struct lttng_event_field *fields;
	unsigned int nrargs;
};

#define CREATE_SYSCALL_TABLE

#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,		\
	},

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

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

/* Create compatibility syscall table */
const struct trace_syscall_entry compat_sc_table[] = {
#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
};

#undef CREATE_SYSCALL_TABLE

static void syscall_entry_unknown(struct lttng_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);
	if (unlikely(is_compat_task()))
		__event_probe__compat_sys_unknown(event, id, args);
	else
		__event_probe__sys_unknown(event, id, args);
}

void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
{
	struct lttng_channel *chan = __data;
	struct lttng_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 = ARRAY_SIZE(compat_sc_table);
		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;
	}
}

/* noinline to diminish caller stack size */
static
int fill_table(const struct trace_syscall_entry *table, size_t table_len,
	struct lttng_event **chan_table, struct lttng_channel *chan, void *filter)
{
	const struct lttng_event_desc *desc;
	unsigned int i;

	/* Allocate events for each syscall, insert into table */
	for (i = 0; i < table_len; i++) {
		struct lttng_kernel_event ev;
		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_KERNEL_SYM_NAME_LEN);
		ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
		ev.instrumentation = LTTNG_KERNEL_NOOP;
		chan_table[i] = lttng_event_create(chan, &ev, filter,
						desc);
		WARN_ON_ONCE(!chan_table[i]);
		if (IS_ERR(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 PTR_ERR(chan_table[i]);
		}
	}
	return 0;
}

int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
{
	struct lttng_kernel_event ev;
	int ret;

	wrapper_vmalloc_sync_all();

	if (!chan->sc_table) {
		/* create syscall table mapping syscall to events */
		chan->sc_table = kzalloc(sizeof(struct lttng_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 lttng_event *)
					* ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
		if (!chan->compat_sc_table)
			return -ENOMEM;
	}
#endif
	if (!chan->sc_unknown) {
		const struct lttng_event_desc *desc =
			&__event_desc___sys_unknown;

		memset(&ev, 0, sizeof(ev));
		strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
		ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
		ev.instrumentation = LTTNG_KERNEL_NOOP;
		chan->sc_unknown = lttng_event_create(chan, &ev, filter,
						    desc);
		WARN_ON_ONCE(!chan->sc_unknown);
		if (IS_ERR(chan->sc_unknown)) {
			return PTR_ERR(chan->sc_unknown);
		}
	}

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

		memset(&ev, 0, sizeof(ev));
		strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
		ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
		ev.instrumentation = LTTNG_KERNEL_NOOP;
		chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter,
							   desc);
		WARN_ON_ONCE(!chan->sc_unknown);
		if (IS_ERR(chan->sc_compat_unknown)) {
			return PTR_ERR(chan->sc_compat_unknown);
		}
	}

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

		memset(&ev, 0, sizeof(ev));
		strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
		ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
		ev.instrumentation = LTTNG_KERNEL_NOOP;
		chan->sc_exit = lttng_event_create(chan, &ev, filter,
						 desc);
		WARN_ON_ONCE(!chan->sc_exit);
		if (IS_ERR(chan->sc_exit)) {
			return PTR_ERR(chan->sc_exit);
		}
	}

	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, ARRAY_SIZE(compat_sc_table),
			chan->compat_sc_table, chan, filter);
	if (ret)
		return ret;
#endif
	ret = lttng_wrapper_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 = lttng_wrapper_tracepoint_probe_register("sys_exit",
			(void *) __event_probe__exit_syscall,
			chan->sc_exit);
	if (ret) {
		WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
			(void *) syscall_entry_probe, chan));
	}
	return ret;
}

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

	if (!chan->sc_table)
		return 0;
	ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
			(void *) __event_probe__exit_syscall,
			chan->sc_exit);
	if (ret)
		return ret;
	ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
			(void *) syscall_entry_probe, chan);
	if (ret)
		return ret;
	/* lttng_event destroy will be performed by lttng_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	* LTTng syscall probes.
259b6cb3	5	*
886d51a3 MD	6	* Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*
	8	* This library is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; only
	11	* version 2.1 of the License.
	12	*
	13	* This library is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with this library; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
259b6cb3 MD	21	*/
	22
	23	#include <linux/module.h>
	24	#include <linux/slab.h>
6333ace3	25	#include <linux/compat.h>
abc0446a	26	#include <linux/err.h>
259b6cb3 MD	27	#include <asm/ptrace.h>
	28	#include <asm/syscall.h>
	29
3a523f5b	30	#include "wrapper/tracepoint.h"
a90917c3	31	#include "lttng-events.h"
259b6cb3	32
6333ace3	33	#ifndef CONFIG_COMPAT
bfa949bf MD	34	# ifndef is_compat_task
	35	# define is_compat_task() (0)
	36	# endif
6333ace3 MD	37	#endif
6333ace3 MD	38
a93244f8	39	static
2faf7d1b	40	void syscall_entry_probe(void __data, struct pt_regs regs, long id);
259b6cb3	41
3a523f5b MD	42	/*
	43	* Forward declarations for old kernels.
	44	*/
	45	struct mmsghdr;
	46	struct rlimit64;
	47	struct oldold_utsname;
	48	struct old_utsname;
	49	struct sel_arg_struct;
	50	struct mmap_arg_struct;
50cd7500	51	struct file_handle;
3a523f5b	52
f7bdf4db MD	53	/*
	54	* Take care of NOARGS not supported by mainline.
	55	*/
	56	#define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print)
	57	#define DEFINE_EVENT_NOARGS(template, name)
	58	#define TRACE_EVENT_NOARGS(name, struct, assign, print)
	59
259b6cb3 MD	60	/*
	61	* Create LTTng tracepoint probes.
	62	*/
	63	#define LTTNG_PACKAGE_BUILD
	64	#define CREATE_TRACE_POINTS
2655f9ad	65	#define TP_MODULE_NOINIT
2f804c0a	66	#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers
259b6cb3	67
a93244f8 MD	68	#define PARAMS(args...) args
a93244f8 MD	69
259b6cb3	70	/* Hijack probe callback for system calls */
a93244f8	71	#undef TP_PROBE_CB
259b6cb3	72	#define TP_PROBE_CB(_template) &syscall_entry_probe
a93244f8 MD	73	#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
	74	TRACE_EVENT(_name, PARAMS(_proto), PARAMS(_args),\
	75	PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
	76	#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
	77	DECLARE_EVENT_CLASS_NOARGS(_name, PARAMS(_struct), PARAMS(_assign),\
	78	PARAMS(_printk))
	79	#define SC_DEFINE_EVENT_NOARGS(_template, _name) \
	80	DEFINE_EVENT_NOARGS(_template, _name)
	81	#undef TRACE_SYSTEM
	82	#define TRACE_SYSTEM syscalls_integers
177b3692	83	#include "instrumentation/syscalls/headers/syscalls_integers.h"
a93244f8 MD	84	#undef TRACE_SYSTEM
a93244f8 MD	85	#define TRACE_SYSTEM syscalls_pointers
177b3692	86	#include "instrumentation/syscalls/headers/syscalls_pointers.h"
a93244f8 MD	87	#undef TRACE_SYSTEM
	88	#undef SC_TRACE_EVENT
	89	#undef SC_DECLARE_EVENT_CLASS_NOARGS
	90	#undef SC_DEFINE_EVENT_NOARGS
2f804c0a	91
a93244f8	92	#define TRACE_SYSTEM syscalls_unknown
63728b02	93	#include "instrumentation/syscalls/headers/syscalls_unknown.h"
a93244f8 MD	94	#undef TRACE_SYSTEM
	95
	96	/* For compat syscalls */
	97	#undef _TRACE_SYSCALLS_integers_H
	98	#undef _TRACE_SYSCALLS_pointers_H
	99
	100	/* Hijack probe callback for system calls */
	101	#undef TP_PROBE_CB
	102	#define TP_PROBE_CB(_template) &syscall_entry_probe
	103	#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
	104	TRACE_EVENT(compat_##_name, PARAMS(_proto), PARAMS(_args), \
	105	PARAMS(_struct), PARAMS(_assign), \
	106	PARAMS(_printk))
	107	#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
	108	DECLARE_EVENT_CLASS_NOARGS(compat_##_name, PARAMS(_struct), \
	109	PARAMS(_assign), PARAMS(_printk))
	110	#define SC_DEFINE_EVENT_NOARGS(_template, _name) \
	111	DEFINE_EVENT_NOARGS(compat_##_template, compat_##_name)
	112	#define TRACE_SYSTEM compat_syscalls_integers
	113	#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
	114	#undef TRACE_SYSTEM
	115	#define TRACE_SYSTEM compat_syscalls_pointers
	116	#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
	117	#undef TRACE_SYSTEM
	118	#undef SC_TRACE_EVENT
	119	#undef SC_DECLARE_EVENT_CLASS_NOARGS
	120	#undef SC_DEFINE_EVENT_NOARGS
	121	#undef TP_PROBE_CB
259b6cb3	122
2655f9ad	123	#undef TP_MODULE_NOINIT
259b6cb3 MD	124	#undef LTTNG_PACKAGE_BUILD
	125	#undef CREATE_TRACE_POINTS
	126
a93244f8 MD	127	struct trace_syscall_entry {
	128	void *func;
	129	const struct lttng_event_desc *desc;
	130	const struct lttng_event_field *fields;
	131	unsigned int nrargs;
	132	};
	133
	134	#define CREATE_SYSCALL_TABLE
	135
259b6cb3	136	#undef TRACE_SYSCALL_TABLE
f7bdf4db	137	#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
259b6cb3	138	[ _nr ] = { \
f7bdf4db	139	.func = __event_probe__##_template, \
259b6cb3	140	.nrargs = (_nrargs), \
f7bdf4db MD	141	.fields = __event_fields___##_template, \
f7bdf4db MD	142	.desc = &__event_desc___##_name, \
259b6cb3 MD	143	},
259b6cb3 MD	144
49c50022	145	static const struct trace_syscall_entry sc_table[] = {
177b3692 MD	146	#include "instrumentation/syscalls/headers/syscalls_integers.h"
177b3692 MD	147	#include "instrumentation/syscalls/headers/syscalls_pointers.h"
259b6cb3 MD	148	};
259b6cb3 MD	149
a93244f8 MD	150	#undef TRACE_SYSCALL_TABLE
	151	#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
	152	[ _nr ] = { \
	153	.func = __event_probe__##compat_##_template, \
	154	.nrargs = (_nrargs), \
	155	.fields = __event_fields___##compat_##_template,\
	156	.desc = &__event_desc___##compat_##_name, \
	157	},
	158
	159	/* Create compatibility syscall table */
	160	const struct trace_syscall_entry compat_sc_table[] = {
	161	#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
	162	#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
	163	};
259b6cb3	164
a93244f8	165	#undef CREATE_SYSCALL_TABLE
2faf7d1b	166
a90917c3	167	static void syscall_entry_unknown(struct lttng_event *event,
f405cfce MD	168	struct pt_regs *regs, unsigned int id)
	169	{
	170	unsigned long args[UNKNOWN_SYSCALL_NRARGS];
f405cfce	171
f405cfce	172	syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
a93244f8 MD	173	if (unlikely(is_compat_task()))
	174	__event_probe__compat_sys_unknown(event, id, args);
	175	else
	176	__event_probe__sys_unknown(event, id, args);
f405cfce MD	177	}
f405cfce MD	178
2faf7d1b	179	void syscall_entry_probe(void __data, struct pt_regs regs, long id)
259b6cb3	180	{
a90917c3 MD	181	struct lttng_channel *chan = __data;
a90917c3 MD	182	struct lttng_event event, unknown_event;
49c50022 MD	183	const struct trace_syscall_entry table, entry;
49c50022 MD	184	size_t table_len;
259b6cb3	185
b76dc1a0	186	if (unlikely(is_compat_task())) {
49c50022	187	table = compat_sc_table;
a93244f8	188	table_len = ARRAY_SIZE(compat_sc_table);
49c50022 MD	189	unknown_event = chan->sc_compat_unknown;
	190	} else {
	191	table = sc_table;
	192	table_len = ARRAY_SIZE(sc_table);
	193	unknown_event = chan->sc_unknown;
b76dc1a0	194	}
49c50022 MD	195	if (unlikely(id >= table_len)) {
49c50022 MD	196	syscall_entry_unknown(unknown_event, regs, id);
259b6cb3	197	return;
f405cfce	198	}
49c50022 MD	199	if (unlikely(is_compat_task()))
	200	event = chan->compat_sc_table[id];
	201	else
	202	event = chan->sc_table[id];
f405cfce	203	if (unlikely(!event)) {
49c50022	204	syscall_entry_unknown(unknown_event, regs, id);
f405cfce MD	205	return;
f405cfce MD	206	}
49c50022	207	entry = &table[id];
f405cfce	208	WARN_ON_ONCE(!entry);
259b6cb3 MD	209
	210	switch (entry->nrargs) {
	211	case 0:
	212	{
	213	void (fptr)(void __data) = entry->func;
	214
	215	fptr(event);
	216	break;
	217	}
	218	case 1:
	219	{
	220	void (fptr)(void __data, unsigned long arg0) = entry->func;
	221	unsigned long args[1];
	222
	223	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	224	fptr(event, args[0]);
	225	break;
	226	}
	227	case 2:
	228	{
	229	void (fptr)(void __data,
	230	unsigned long arg0,
	231	unsigned long arg1) = entry->func;
	232	unsigned long args[2];
	233
	234	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	235	fptr(event, args[0], args[1]);
	236	break;
	237	}
	238	case 3:
	239	{
	240	void (fptr)(void __data,
	241	unsigned long arg0,
	242	unsigned long arg1,
	243	unsigned long arg2) = entry->func;
	244	unsigned long args[3];
	245
	246	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	247	fptr(event, args[0], args[1], args[2]);
	248	break;
	249	}
	250	case 4:
	251	{
	252	void (fptr)(void __data,
	253	unsigned long arg0,
	254	unsigned long arg1,
	255	unsigned long arg2,
	256	unsigned long arg3) = entry->func;
	257	unsigned long args[4];
	258
	259	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	260	fptr(event, args[0], args[1], args[2], args[3]);
	261	break;
	262	}
	263	case 5:
	264	{
	265	void (fptr)(void __data,
	266	unsigned long arg0,
	267	unsigned long arg1,
	268	unsigned long arg2,
	269	unsigned long arg3,
	270	unsigned long arg4) = entry->func;
	271	unsigned long args[5];
	272
273	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
274	fptr(event, args[0], args[1], args[2], args[3], args[4]);
275	break;
276	}
277	case 6:
278	{
279	void (fptr)(void __data,
280	unsigned long arg0,
281	unsigned long arg1,
282	unsigned long arg2,
283	unsigned long arg3,
284	unsigned long arg4,
285	unsigned long arg5) = entry->func;
286	unsigned long args[6];
287
288	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
289	fptr(event, args[0], args[1], args[2],
290	args[3], args[4], args[5]);
291	break;
292	}
293	default:
294	break;
295	}
296	}
297
2a0c4816	298	/* noinline to diminish caller stack size */
49c50022 MD	299	static
49c50022 MD	300	int fill_table(const struct trace_syscall_entry *table, size_t table_len,
a90917c3	301	struct lttng_event *chan_table, struct lttng_channel chan, void *filter)
259b6cb3	302	{
2a0c4816	303	const struct lttng_event_desc *desc;
259b6cb3	304	unsigned int i;
49c50022 MD	305
	306	/* Allocate events for each syscall, insert into table */
	307	for (i = 0; i < table_len; i++) {
	308	struct lttng_kernel_event ev;
2a0c4816	309	desc = table[i].desc;
49c50022 MD	310
	311	if (!desc) {
	312	/* Unknown syscall */
	313	continue;
	314	}
	315	/*
	316	* Skip those already populated by previous failed
	317	* register for this channel.
	318	*/
	319	if (chan_table[i])
	320	continue;
	321	memset(&ev, 0, sizeof(ev));
f8695253 MD	322	strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
f8695253 MD	323	ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
49c50022	324	ev.instrumentation = LTTNG_KERNEL_NOOP;
a90917c3	325	chan_table[i] = lttng_event_create(chan, &ev, filter,
49c50022	326	desc);
abc0446a MD	327	WARN_ON_ONCE(!chan_table[i]);
abc0446a MD	328	if (IS_ERR(chan_table[i])) {
49c50022 MD	329	/*
	330	* If something goes wrong in event registration
	331	* after the first one, we have no choice but to
	332	* leave the previous events in there, until
	333	* deleted by session teardown.
	334	*/
abc0446a	335	return PTR_ERR(chan_table[i]);
49c50022 MD	336	}
	337	}
	338	return 0;
	339	}
	340
a90917c3	341	int lttng_syscalls_register(struct lttng_channel chan, void filter)
49c50022	342	{
2a0c4816	343	struct lttng_kernel_event ev;
259b6cb3 MD	344	int ret;
	345
	346	wrapper_vmalloc_sync_all();
259b6cb3 MD	347
	348	if (!chan->sc_table) {
	349	/* create syscall table mapping syscall to events */
a90917c3	350	chan->sc_table = kzalloc(sizeof(struct lttng_event *)
259b6cb3 MD	351	* ARRAY_SIZE(sc_table), GFP_KERNEL);
	352	if (!chan->sc_table)
	353	return -ENOMEM;
	354	}
	355
49c50022 MD	356	#ifdef CONFIG_COMPAT
	357	if (!chan->compat_sc_table) {
	358	/* create syscall table mapping compat syscall to events */
a90917c3	359	chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *)
a93244f8	360	* ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
49c50022 MD	361	if (!chan->compat_sc_table)
	362	return -ENOMEM;
	363	}
	364	#endif
f405cfce	365	if (!chan->sc_unknown) {
f405cfce MD	366	const struct lttng_event_desc *desc =
f405cfce MD	367	&__event_desc___sys_unknown;
2f804c0a	368
f405cfce	369	memset(&ev, 0, sizeof(ev));
f8695253 MD	370	strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
f8695253 MD	371	ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
f405cfce	372	ev.instrumentation = LTTNG_KERNEL_NOOP;
a90917c3	373	chan->sc_unknown = lttng_event_create(chan, &ev, filter,
f405cfce	374	desc);
abc0446a MD	375	WARN_ON_ONCE(!chan->sc_unknown);
	376	if (IS_ERR(chan->sc_unknown)) {
	377	return PTR_ERR(chan->sc_unknown);
f405cfce MD	378	}
	379	}
	380
b76dc1a0	381	if (!chan->sc_compat_unknown) {
b76dc1a0 MD	382	const struct lttng_event_desc *desc =
	383	&__event_desc___compat_sys_unknown;
	384
	385	memset(&ev, 0, sizeof(ev));
f8695253 MD	386	strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
f8695253 MD	387	ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
b76dc1a0	388	ev.instrumentation = LTTNG_KERNEL_NOOP;
a90917c3	389	chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter,
b76dc1a0	390	desc);
abc0446a MD	391	WARN_ON_ONCE(!chan->sc_unknown);
	392	if (IS_ERR(chan->sc_compat_unknown)) {
	393	return PTR_ERR(chan->sc_compat_unknown);
b76dc1a0 MD	394	}
	395	}
	396
2f804c0a	397	if (!chan->sc_exit) {
2f804c0a MD	398	const struct lttng_event_desc *desc =
	399	&__event_desc___exit_syscall;
	400
	401	memset(&ev, 0, sizeof(ev));
f8695253 MD	402	strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
f8695253 MD	403	ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
2f804c0a	404	ev.instrumentation = LTTNG_KERNEL_NOOP;
a90917c3	405	chan->sc_exit = lttng_event_create(chan, &ev, filter,
2f804c0a	406	desc);
abc0446a MD	407	WARN_ON_ONCE(!chan->sc_exit);
	408	if (IS_ERR(chan->sc_exit)) {
	409	return PTR_ERR(chan->sc_exit);
2f804c0a MD	410	}
	411	}
	412
49c50022 MD	413	ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
	414	chan->sc_table, chan, filter);
	415	if (ret)
	416	return ret;
	417	#ifdef CONFIG_COMPAT
a93244f8	418	ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
49c50022 MD	419	chan->compat_sc_table, chan, filter);
	420	if (ret)
	421	return ret;
	422	#endif
20591cf7	423	ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
259b6cb3	424	(void *) syscall_entry_probe, chan);
63728b02 MD	425	if (ret)
	426	return ret;
	427	/*
	428	* We change the name of sys_exit tracepoint due to namespace
	429	* conflict with sys_exit syscall entry.
	430	*/
20591cf7	431	ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
2c01ec07	432	(void *) __event_probe__exit_syscall,
2f804c0a	433	chan->sc_exit);
63728b02	434	if (ret) {
20591cf7	435	WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
63728b02 MD	436	(void *) syscall_entry_probe, chan));
63728b02 MD	437	}
259b6cb3 MD	438	return ret;
	439	}
	440
	441	/*
	442	* Only called at session destruction.
	443	*/
a90917c3	444	int lttng_syscalls_unregister(struct lttng_channel *chan)
259b6cb3 MD	445	{
	446	int ret;
	447
	448	if (!chan->sc_table)
	449	return 0;
20591cf7	450	ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
2c01ec07	451	(void *) __event_probe__exit_syscall,
2f804c0a	452	chan->sc_exit);
63728b02 MD	453	if (ret)
63728b02 MD	454	return ret;
20591cf7	455	ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
259b6cb3 MD	456	(void *) syscall_entry_probe, chan);
	457	if (ret)
	458	return ret;
a90917c3	459	/* lttng_event destroy will be performed by lttng_session_destroy() */
259b6cb3	460	kfree(chan->sc_table);
49c50022 MD	461	#ifdef CONFIG_COMPAT
	462	kfree(chan->compat_sc_table);
	463	#endif
259b6cb3 MD	464	return 0;
259b6cb3 MD	465	}