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

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

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

#include "ltt-events.h"

static 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

/* Hijack probe callback for system calls */
#define TP_PROBE_CB(_template)		&syscall_entry_probe
#define TP_MODULE_OVERRIDE

#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers
#include "instrumentation/syscalls/headers/syscalls_integers.h"
#include "instrumentation/syscalls/headers/syscalls_pointers.h"

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

#undef CREATE_SYSCALL_TABLE

static void syscall_entry_probe(void *__data, struct pt_regs *regs, long id)
{
	struct trace_syscall_entry *entry;
	struct ltt_channel *chan = __data;
	struct ltt_event *event;

	if (unlikely(id >= ARRAY_SIZE(sc_table)))
		return;
	entry = &sc_table[id];
	if (unlikely(!entry->func))
		return;
	event = chan->sc_table[id];
	WARN_ON_ONCE(!event);

	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;
	}
}

int lttng_syscalls_register(struct ltt_channel *chan, void *filter)
{
	unsigned int i;
	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;
	}

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

		if (!desc)
			continue;
		/*
		 * Skip those already populated by previous failed
		 * register for this channel.
		 */
		if (chan->sc_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->sc_table[i] = ltt_event_create(chan, &ev, filter,
						     desc);
		if (!chan->sc_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;
		}
	}
	ret = tracepoint_probe_register("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_enter",
			(void *) syscall_entry_probe, chan);
	if (ret)
		return ret;
	/* ltt_event destroy will be performed by ltt_session_destroy() */
	kfree(chan->sc_table);
	return 0;
}
Commit	Line	Data
259b6cb3 MD	1	/*
	2	* lttng-syscalls.c
	3	*
	4	* Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*
	6	* LTTng sched probes.
	7	*
	8	* Dual LGPL v2.1/GPL v2 license.
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/slab.h>
	13	#include <asm/ptrace.h>
	14	#include <asm/syscall.h>
	15
	16	#include "ltt-events.h"
	17
	18	static void syscall_entry_probe(void __data, struct pt_regs regs, long id);
	19
f7bdf4db MD	20	/*
	21	* Take care of NOARGS not supported by mainline.
	22	*/
	23	#define DECLARE_EVENT_CLASS_NOARGS(name, tstruct, assign, print)
	24	#define DEFINE_EVENT_NOARGS(template, name)
	25	#define TRACE_EVENT_NOARGS(name, struct, assign, print)
	26
259b6cb3 MD	27	/*
	28	* Create LTTng tracepoint probes.
	29	*/
	30	#define LTTNG_PACKAGE_BUILD
	31	#define CREATE_TRACE_POINTS
	32
	33	/* Hijack probe callback for system calls */
	34	#define TP_PROBE_CB(_template) &syscall_entry_probe
	35	#define TP_MODULE_OVERRIDE
	36
	37	#define TRACE_INCLUDE_PATH ../instrumentation/syscalls/headers
177b3692 MD	38	#include "instrumentation/syscalls/headers/syscalls_integers.h"
177b3692 MD	39	#include "instrumentation/syscalls/headers/syscalls_pointers.h"
259b6cb3 MD	40
	41	#undef TP_MODULE_OVERRIDE
	42	#undef TP_PROBE_CB
	43	#undef LTTNG_PACKAGE_BUILD
	44	#undef CREATE_TRACE_POINTS
	45
	46	struct trace_syscall_entry {
	47	void *func;
f7bdf4db	48	const struct lttng_event_desc *desc;
259b6cb3 MD	49	const struct lttng_event_field *fields;
	50	unsigned int nrargs;
	51	};
	52
259b6cb3 MD	53	#define CREATE_SYSCALL_TABLE
	54
	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	},
	63
	64	static struct trace_syscall_entry sc_table[] = {
177b3692 MD	65	#include "instrumentation/syscalls/headers/syscalls_integers.h"
177b3692 MD	66	#include "instrumentation/syscalls/headers/syscalls_pointers.h"
259b6cb3 MD	67	};
	68
	69	#undef CREATE_SYSCALL_TABLE
	70
	71	static void syscall_entry_probe(void __data, struct pt_regs regs, long id)
	72	{
	73	struct trace_syscall_entry *entry;
	74	struct ltt_channel *chan = __data;
	75	struct ltt_event *event;
	76
	77	if (unlikely(id >= ARRAY_SIZE(sc_table)))
	78	return;
	79	entry = &sc_table[id];
	80	if (unlikely(!entry->func))
	81	return;
	82	event = chan->sc_table[id];
	83	WARN_ON_ONCE(!event);
	84
	85	switch (entry->nrargs) {
	86	case 0:
	87	{
	88	void (fptr)(void __data) = entry->func;
	89
	90	fptr(event);
	91	break;
	92	}
	93	case 1:
	94	{
	95	void (fptr)(void __data, unsigned long arg0) = entry->func;
	96	unsigned long args[1];
	97
	98	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	99	fptr(event, args[0]);
	100	break;
	101	}
	102	case 2:
	103	{
	104	void (fptr)(void __data,
	105	unsigned long arg0,
	106	unsigned long arg1) = entry->func;
	107	unsigned long args[2];
	108
	109	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	110	fptr(event, args[0], args[1]);
	111	break;
	112	}
	113	case 3:
	114	{
	115	void (fptr)(void __data,
	116	unsigned long arg0,
	117	unsigned long arg1,
	118	unsigned long arg2) = entry->func;
	119	unsigned long args[3];
	120
	121	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
	122	fptr(event, args[0], args[1], args[2]);
	123	break;
	124	}
	125	case 4:
	126	{
	127	void (fptr)(void __data,
	128	unsigned long arg0,
	129	unsigned long arg1,
	130	unsigned long arg2,
131	unsigned long arg3) = entry->func;
132	unsigned long args[4];
133
134	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
135	fptr(event, args[0], args[1], args[2], args[3]);
136	break;
137	}
138	case 5:
139	{
140	void (fptr)(void __data,
141	unsigned long arg0,
142	unsigned long arg1,
143	unsigned long arg2,
144	unsigned long arg3,
145	unsigned long arg4) = entry->func;
146	unsigned long args[5];
147
148	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
149	fptr(event, args[0], args[1], args[2], args[3], args[4]);
150	break;
151	}
152	case 6:
153	{
154	void (fptr)(void __data,
155	unsigned long arg0,
156	unsigned long arg1,
157	unsigned long arg2,
158	unsigned long arg3,
159	unsigned long arg4,
160	unsigned long arg5) = entry->func;
161	unsigned long args[6];
162
163	syscall_get_arguments(current, regs, 0, entry->nrargs, args);
164	fptr(event, args[0], args[1], args[2],
165	args[3], args[4], args[5]);
166	break;
167	}
168	default:
169	break;
170	}
171	}
172
259b6cb3 MD	173	int lttng_syscalls_register(struct ltt_channel chan, void filter)
	174	{
	175	unsigned int i;
	176	int ret;
	177
	178	wrapper_vmalloc_sync_all();
259b6cb3 MD	179
	180	if (!chan->sc_table) {
	181	/* create syscall table mapping syscall to events */
	182	chan->sc_table = kzalloc(sizeof(struct ltt_event *)
	183	* ARRAY_SIZE(sc_table), GFP_KERNEL);
	184	if (!chan->sc_table)
	185	return -ENOMEM;
	186	}
	187
	188	/* Allocate events for each syscall, insert into table */
	189	for (i = 0; i < ARRAY_SIZE(sc_table); i++) {
	190	struct lttng_kernel_event ev;
	191	const struct lttng_event_desc *desc = sc_table[i].desc;
	192
	193	if (!desc)
	194	continue;
	195	/*
	196	* Skip those already populated by previous failed
	197	* register for this channel.
	198	*/
	199	if (chan->sc_table[i])
	200	continue;
	201	memset(&ev, 0, sizeof(ev));
	202	strncpy(ev.name, desc->name, LTTNG_SYM_NAME_LEN);
	203	ev.name[LTTNG_SYM_NAME_LEN - 1] = '\0';
	204	ev.instrumentation = LTTNG_KERNEL_NOOP;
	205	chan->sc_table[i] = ltt_event_create(chan, &ev, filter,
	206	desc);
	207	if (!chan->sc_table[i]) {
	208	/*
	209	* If something goes wrong in event registration
	210	* after the first one, we have no choice but to
	211	* leave the previous events in there, until
	212	* deleted by session teardown.
	213	*/
	214	return -EINVAL;
	215	}
	216	}
	217	ret = tracepoint_probe_register("sys_enter",
	218	(void *) syscall_entry_probe, chan);
	219	return ret;
	220	}
	221
	222	/*
	223	* Only called at session destruction.
	224	*/
	225	int lttng_syscalls_unregister(struct ltt_channel *chan)
	226	{
	227	int ret;
	228
	229	if (!chan->sc_table)
	230	return 0;
	231	ret = tracepoint_probe_unregister("sys_enter",
	232	(void *) syscall_entry_probe, chan);
	233	if (ret)
	234	return ret;
	235	/* ltt_event destroy will be performed by ltt_session_destroy() */
	236	kfree(chan->sc_table);
	237	return 0;
	238	}