[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;

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