[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 <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);
		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 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);
		if (!chan->sc_unknown) {
			return -EINVAL;
		}
	}

	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);
		if (!chan->sc_compat_unknown) {
			return -EINVAL;
		}
	}

	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);
		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, ARRAY_SIZE(compat_sc_table),
			chan->compat_sc_table, chan, filter);
	if (ret)
		return ret;
#endif
	ret = kabi_2635_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 = kabi_2635_tracepoint_probe_register("sys_exit",
			(void *) __event_probe__exit_syscall,
			chan->sc_exit);
	if (ret) {
		WARN_ON_ONCE(kabi_2635_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 = kabi_2635_tracepoint_probe_unregister("sys_exit",
			(void *) __event_probe__exit_syscall,
			chan->sc_exit);
	if (ret)
		return ret;
	ret = kabi_2635_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>
259b6cb3 MD	26	#include <asm/ptrace.h>
	27	#include <asm/syscall.h>
	28
3a523f5b	29	#include "wrapper/tracepoint.h"
a90917c3	30	#include "lttng-events.h"
259b6cb3	31
6333ace3	32	#ifndef CONFIG_COMPAT
bfa949bf MD	33	# ifndef is_compat_task
	34	# define is_compat_task() (0)
	35	# endif
6333ace3 MD	36	#endif
6333ace3 MD	37
a93244f8	38	static
2faf7d1b	39	void syscall_entry_probe(void __data, struct pt_regs regs, long id);
259b6cb3	40
3a523f5b MD	41	/*
	42	* Forward declarations for old kernels.
	43	*/
	44	struct mmsghdr;
	45	struct rlimit64;
	46	struct oldold_utsname;
	47	struct old_utsname;
	48	struct sel_arg_struct;
	49	struct mmap_arg_struct;
	50
f7bdf4db MD	51	/*
	52	* Take care of NOARGS not supported by mainline.
	53	*/
	54	#define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print)
	55	#define DEFINE_EVENT_NOARGS(template, name)
	56	#define TRACE_EVENT_NOARGS(name, struct, assign, print)
	57
259b6cb3 MD	58	/*
	59	* Create LTTng tracepoint probes.
	60	*/
	61	#define LTTNG_PACKAGE_BUILD
	62	#define CREATE_TRACE_POINTS
2655f9ad	63	#define TP_MODULE_NOINIT
2f804c0a	64	#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers
259b6cb3	65
a93244f8 MD	66	#define PARAMS(args...) args
a93244f8 MD	67
259b6cb3	68	/* Hijack probe callback for system calls */
a93244f8	69	#undef TP_PROBE_CB
259b6cb3	70	#define TP_PROBE_CB(_template) &syscall_entry_probe
a93244f8 MD	71	#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
	72	TRACE_EVENT(_name, PARAMS(_proto), PARAMS(_args),\
	73	PARAMS(_struct), PARAMS(_assign), PARAMS(_printk))
	74	#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
	75	DECLARE_EVENT_CLASS_NOARGS(_name, PARAMS(_struct), PARAMS(_assign),\
	76	PARAMS(_printk))
	77	#define SC_DEFINE_EVENT_NOARGS(_template, _name) \
	78	DEFINE_EVENT_NOARGS(_template, _name)
	79	#undef TRACE_SYSTEM
	80	#define TRACE_SYSTEM syscalls_integers
177b3692	81	#include "instrumentation/syscalls/headers/syscalls_integers.h"
a93244f8 MD	82	#undef TRACE_SYSTEM
a93244f8 MD	83	#define TRACE_SYSTEM syscalls_pointers
177b3692	84	#include "instrumentation/syscalls/headers/syscalls_pointers.h"
a93244f8 MD	85	#undef TRACE_SYSTEM
	86	#undef SC_TRACE_EVENT
	87	#undef SC_DECLARE_EVENT_CLASS_NOARGS
	88	#undef SC_DEFINE_EVENT_NOARGS
2f804c0a	89
a93244f8	90	#define TRACE_SYSTEM syscalls_unknown
63728b02	91	#include "instrumentation/syscalls/headers/syscalls_unknown.h"
a93244f8 MD	92	#undef TRACE_SYSTEM
	93
	94	/* For compat syscalls */
	95	#undef _TRACE_SYSCALLS_integers_H
	96	#undef _TRACE_SYSCALLS_pointers_H
	97
	98	/* Hijack probe callback for system calls */
	99	#undef TP_PROBE_CB
	100	#define TP_PROBE_CB(_template) &syscall_entry_probe
	101	#define SC_TRACE_EVENT(_name, _proto, _args, _struct, _assign, _printk) \
	102	TRACE_EVENT(compat_##_name, PARAMS(_proto), PARAMS(_args), \
	103	PARAMS(_struct), PARAMS(_assign), \
	104	PARAMS(_printk))
	105	#define SC_DECLARE_EVENT_CLASS_NOARGS(_name, _struct, _assign, _printk) \
	106	DECLARE_EVENT_CLASS_NOARGS(compat_##_name, PARAMS(_struct), \
	107	PARAMS(_assign), PARAMS(_printk))
	108	#define SC_DEFINE_EVENT_NOARGS(_template, _name) \
	109	DEFINE_EVENT_NOARGS(compat_##_template, compat_##_name)
	110	#define TRACE_SYSTEM compat_syscalls_integers
	111	#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
	112	#undef TRACE_SYSTEM
	113	#define TRACE_SYSTEM compat_syscalls_pointers
	114	#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
	115	#undef TRACE_SYSTEM
	116	#undef SC_TRACE_EVENT
	117	#undef SC_DECLARE_EVENT_CLASS_NOARGS
	118	#undef SC_DEFINE_EVENT_NOARGS
	119	#undef TP_PROBE_CB
259b6cb3	120
2655f9ad	121	#undef TP_MODULE_NOINIT
259b6cb3 MD	122	#undef LTTNG_PACKAGE_BUILD
	123	#undef CREATE_TRACE_POINTS
	124
a93244f8 MD	125	struct trace_syscall_entry {
	126	void *func;
	127	const struct lttng_event_desc *desc;
	128	const struct lttng_event_field *fields;
	129	unsigned int nrargs;
	130	};
	131
	132	#define CREATE_SYSCALL_TABLE
	133
259b6cb3	134	#undef TRACE_SYSCALL_TABLE
f7bdf4db	135	#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
259b6cb3	136	[ _nr ] = { \
f7bdf4db	137	.func = __event_probe__##_template, \
259b6cb3	138	.nrargs = (_nrargs), \
f7bdf4db MD	139	.fields = __event_fields___##_template, \
f7bdf4db MD	140	.desc = &__event_desc___##_name, \
259b6cb3 MD	141	},
259b6cb3 MD	142
49c50022	143	static const struct trace_syscall_entry sc_table[] = {
177b3692 MD	144	#include "instrumentation/syscalls/headers/syscalls_integers.h"
177b3692 MD	145	#include "instrumentation/syscalls/headers/syscalls_pointers.h"
259b6cb3 MD	146	};
259b6cb3 MD	147
a93244f8 MD	148	#undef TRACE_SYSCALL_TABLE
	149	#define TRACE_SYSCALL_TABLE(_template, _name, _nr, _nrargs) \
	150	[ _nr ] = { \
	151	.func = __event_probe__##compat_##_template, \
	152	.nrargs = (_nrargs), \
	153	.fields = __event_fields___##compat_##_template,\
	154	.desc = &__event_desc___##compat_##_name, \
	155	},
	156
	157	/* Create compatibility syscall table */
	158	const struct trace_syscall_entry compat_sc_table[] = {
	159	#include "instrumentation/syscalls/headers/compat_syscalls_integers.h"
	160	#include "instrumentation/syscalls/headers/compat_syscalls_pointers.h"
	161	};
259b6cb3	162
a93244f8	163	#undef CREATE_SYSCALL_TABLE
2faf7d1b	164
a90917c3	165	static void syscall_entry_unknown(struct lttng_event *event,
f405cfce MD	166	struct pt_regs *regs, unsigned int id)
	167	{
	168	unsigned long args[UNKNOWN_SYSCALL_NRARGS];
f405cfce	169
f405cfce	170	syscall_get_arguments(current, regs, 0, UNKNOWN_SYSCALL_NRARGS, args);
a93244f8 MD	171	if (unlikely(is_compat_task()))
	172	__event_probe__compat_sys_unknown(event, id, args);
	173	else
	174	__event_probe__sys_unknown(event, id, args);
f405cfce MD	175	}
f405cfce MD	176
2faf7d1b	177	void syscall_entry_probe(void __data, struct pt_regs regs, long id)
259b6cb3	178	{
a90917c3 MD	179	struct lttng_channel *chan = __data;
a90917c3 MD	180	struct lttng_event event, unknown_event;
49c50022 MD	181	const struct trace_syscall_entry table, entry;
49c50022 MD	182	size_t table_len;
259b6cb3	183
b76dc1a0	184	if (unlikely(is_compat_task())) {
49c50022	185	table = compat_sc_table;
a93244f8	186	table_len = ARRAY_SIZE(compat_sc_table);
49c50022 MD	187	unknown_event = chan->sc_compat_unknown;
	188	} else {
	189	table = sc_table;
	190	table_len = ARRAY_SIZE(sc_table);
	191	unknown_event = chan->sc_unknown;
b76dc1a0	192	}
49c50022 MD	193	if (unlikely(id >= table_len)) {
49c50022 MD	194	syscall_entry_unknown(unknown_event, regs, id);
259b6cb3	195	return;
f405cfce	196	}
49c50022 MD	197	if (unlikely(is_compat_task()))
	198	event = chan->compat_sc_table[id];
	199	else
	200	event = chan->sc_table[id];
f405cfce	201	if (unlikely(!event)) {
49c50022	202	syscall_entry_unknown(unknown_event, regs, id);
f405cfce MD	203	return;
f405cfce MD	204	}
49c50022	205	entry = &table[id];
f405cfce	206	WARN_ON_ONCE(!entry);
259b6cb3 MD	207
	208	switch (entry->nrargs) {
	209	case 0:
	210	{
	211	void (fptr)(void __data) = entry->func;
	212
	213	fptr(event);
	214	break;
	215	}
	216	case 1:
	217	{
	218	void (fptr)(void __data, unsigned long arg0) = entry->func;
	219	unsigned long args[1];
	220
	221	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	222	fptr(event, args[0]);
	223	break;
	224	}
	225	case 2:
	226	{
	227	void (fptr)(void __data,
	228	unsigned long arg0,
	229	unsigned long arg1) = entry->func;
	230	unsigned long args[2];
	231
	232	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	233	fptr(event, args[0], args[1]);
	234	break;
	235	}
	236	case 3:
	237	{
	238	void (fptr)(void __data,
	239	unsigned long arg0,
	240	unsigned long arg1,
	241	unsigned long arg2) = entry->func;
	242	unsigned long args[3];
	243
	244	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	245	fptr(event, args[0], args[1], args[2]);
	246	break;
	247	}
	248	case 4:
	249	{
	250	void (fptr)(void __data,
	251	unsigned long arg0,
	252	unsigned long arg1,
	253	unsigned long arg2,
	254	unsigned long arg3) = entry->func;
	255	unsigned long args[4];
	256
	257	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	258	fptr(event, args[0], args[1], args[2], args[3]);
	259	break;
	260	}
	261	case 5:
	262	{
	263	void (fptr)(void __data,
	264	unsigned long arg0,
	265	unsigned long arg1,
	266	unsigned long arg2,
	267	unsigned long arg3,
	268	unsigned long arg4) = entry->func;
	269	unsigned long args[5];
	270
271	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
272	fptr(event, args[0], args[1], args[2], args[3], args[4]);
273	break;
274	}
275	case 6:
276	{
277	void (fptr)(void __data,
278	unsigned long arg0,
279	unsigned long arg1,
280	unsigned long arg2,
281	unsigned long arg3,
282	unsigned long arg4,
283	unsigned long arg5) = entry->func;
284	unsigned long args[6];
285
286	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
287	fptr(event, args[0], args[1], args[2],
288	args[3], args[4], args[5]);
289	break;
290	}
291	default:
292	break;
293	}
294	}
295
2a0c4816	296	/* noinline to diminish caller stack size */
49c50022 MD	297	static
49c50022 MD	298	int fill_table(const struct trace_syscall_entry *table, size_t table_len,
a90917c3	299	struct lttng_event *chan_table, struct lttng_channel chan, void *filter)
259b6cb3	300	{
2a0c4816	301	const struct lttng_event_desc *desc;
259b6cb3	302	unsigned int i;
49c50022 MD	303
	304	/* Allocate events for each syscall, insert into table */
	305	for (i = 0; i < table_len; i++) {
	306	struct lttng_kernel_event ev;
2a0c4816	307	desc = table[i].desc;
49c50022 MD	308
	309	if (!desc) {
	310	/* Unknown syscall */
	311	continue;
	312	}
	313	/*
	314	* Skip those already populated by previous failed
	315	* register for this channel.
	316	*/
	317	if (chan_table[i])
	318	continue;
	319	memset(&ev, 0, sizeof(ev));
f8695253 MD	320	strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
f8695253 MD	321	ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
49c50022	322	ev.instrumentation = LTTNG_KERNEL_NOOP;
a90917c3	323	chan_table[i] = lttng_event_create(chan, &ev, filter,
49c50022 MD	324	desc);
	325	if (!chan_table[i]) {
	326	/*
	327	* If something goes wrong in event registration
	328	* after the first one, we have no choice but to
	329	* leave the previous events in there, until
	330	* deleted by session teardown.
	331	*/
	332	return -EINVAL;
	333	}
	334	}
	335	return 0;
	336	}
	337
a90917c3	338	int lttng_syscalls_register(struct lttng_channel chan, void filter)
49c50022	339	{
2a0c4816	340	struct lttng_kernel_event ev;
259b6cb3 MD	341	int ret;
	342
	343	wrapper_vmalloc_sync_all();
259b6cb3 MD	344
	345	if (!chan->sc_table) {
	346	/* create syscall table mapping syscall to events */
a90917c3	347	chan->sc_table = kzalloc(sizeof(struct lttng_event *)
259b6cb3 MD	348	* ARRAY_SIZE(sc_table), GFP_KERNEL);
	349	if (!chan->sc_table)
	350	return -ENOMEM;
	351	}
	352
49c50022 MD	353	#ifdef CONFIG_COMPAT
	354	if (!chan->compat_sc_table) {
	355	/* create syscall table mapping compat syscall to events */
a90917c3	356	chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *)
a93244f8	357	* ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
49c50022 MD	358	if (!chan->compat_sc_table)
	359	return -ENOMEM;
	360	}
	361	#endif
f405cfce	362	if (!chan->sc_unknown) {
f405cfce MD	363	const struct lttng_event_desc *desc =
f405cfce MD	364	&__event_desc___sys_unknown;
2f804c0a	365
f405cfce	366	memset(&ev, 0, sizeof(ev));
f8695253 MD	367	strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
f8695253 MD	368	ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
f405cfce	369	ev.instrumentation = LTTNG_KERNEL_NOOP;
a90917c3	370	chan->sc_unknown = lttng_event_create(chan, &ev, filter,
f405cfce MD	371	desc);
	372	if (!chan->sc_unknown) {
	373	return -EINVAL;
	374	}
	375	}
	376
b76dc1a0	377	if (!chan->sc_compat_unknown) {
b76dc1a0 MD	378	const struct lttng_event_desc *desc =
	379	&__event_desc___compat_sys_unknown;
	380
	381	memset(&ev, 0, sizeof(ev));
f8695253 MD	382	strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
f8695253 MD	383	ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
b76dc1a0	384	ev.instrumentation = LTTNG_KERNEL_NOOP;
a90917c3	385	chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter,
b76dc1a0 MD	386	desc);
	387	if (!chan->sc_compat_unknown) {
	388	return -EINVAL;
	389	}
	390	}
	391
2f804c0a	392	if (!chan->sc_exit) {
2f804c0a MD	393	const struct lttng_event_desc *desc =
	394	&__event_desc___exit_syscall;
	395
	396	memset(&ev, 0, sizeof(ev));
f8695253 MD	397	strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
f8695253 MD	398	ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
2f804c0a	399	ev.instrumentation = LTTNG_KERNEL_NOOP;
a90917c3	400	chan->sc_exit = lttng_event_create(chan, &ev, filter,
2f804c0a MD	401	desc);
	402	if (!chan->sc_exit) {
	403	return -EINVAL;
	404	}
	405	}
	406
49c50022 MD	407	ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
	408	chan->sc_table, chan, filter);
	409	if (ret)
	410	return ret;
	411	#ifdef CONFIG_COMPAT
a93244f8	412	ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
49c50022 MD	413	chan->compat_sc_table, chan, filter);
	414	if (ret)
	415	return ret;
	416	#endif
3a523f5b	417	ret = kabi_2635_tracepoint_probe_register("sys_enter",
259b6cb3	418	(void *) syscall_entry_probe, chan);
63728b02 MD	419	if (ret)
	420	return ret;
	421	/*
	422	* We change the name of sys_exit tracepoint due to namespace
	423	* conflict with sys_exit syscall entry.
	424	*/
3a523f5b	425	ret = kabi_2635_tracepoint_probe_register("sys_exit",
2c01ec07	426	(void *) __event_probe__exit_syscall,
2f804c0a	427	chan->sc_exit);
63728b02	428	if (ret) {
3a523f5b	429	WARN_ON_ONCE(kabi_2635_tracepoint_probe_unregister("sys_enter",
63728b02 MD	430	(void *) syscall_entry_probe, chan));
63728b02 MD	431	}
259b6cb3 MD	432	return ret;
	433	}
	434
	435	/*
	436	* Only called at session destruction.
	437	*/
a90917c3	438	int lttng_syscalls_unregister(struct lttng_channel *chan)
259b6cb3 MD	439	{
	440	int ret;
	441
	442	if (!chan->sc_table)
	443	return 0;
3a523f5b	444	ret = kabi_2635_tracepoint_probe_unregister("sys_exit",
2c01ec07	445	(void *) __event_probe__exit_syscall,
2f804c0a	446	chan->sc_exit);
63728b02 MD	447	if (ret)
63728b02 MD	448	return ret;
3a523f5b	449	ret = kabi_2635_tracepoint_probe_unregister("sys_enter",
259b6cb3 MD	450	(void *) syscall_entry_probe, chan);
	451	if (ret)
	452	return ret;
a90917c3	453	/* lttng_event destroy will be performed by lttng_session_destroy() */
259b6cb3	454	kfree(chan->sc_table);
49c50022 MD	455	#ifdef CONFIG_COMPAT
	456	kfree(chan->compat_sc_table);
	457	#endif
259b6cb3 MD	458	return 0;
259b6cb3 MD	459	}