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

/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
 *
 * lttng-context.c
 *
 * LTTng trace/channel/event context management.
 *
 * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#include <linux/module.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <wrapper/vmalloc.h>	/* for wrapper_vmalloc_sync_all() */
#include <lttng-events.h>
#include <lttng-tracer.h>

/*
 * The filter implementation requires that two consecutive "get" for the
 * same context performed by the same thread return the same result.
 */

/*
 * Static array of contexts, for $ctx filters.
 */
struct lttng_ctx *lttng_static_ctx;

int lttng_find_context(struct lttng_ctx *ctx, const char *name)
{
	unsigned int i;

	for (i = 0; i < ctx->nr_fields; i++) {
		/* Skip allocated (but non-initialized) contexts */
		if (!ctx->fields[i].event_field.name)
			continue;
		if (!strcmp(ctx->fields[i].event_field.name, name))
			return 1;
	}
	return 0;
}
EXPORT_SYMBOL_GPL(lttng_find_context);

int lttng_get_context_index(struct lttng_ctx *ctx, const char *name)
{
	unsigned int i;
	const char *subname;

	if (!ctx)
		return -1;
	if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) {
		subname = name + strlen("$ctx.");
	} else {
		subname = name;
	}
	for (i = 0; i < ctx->nr_fields; i++) {
		/* Skip allocated (but non-initialized) contexts */
		if (!ctx->fields[i].event_field.name)
			continue;
		if (!strcmp(ctx->fields[i].event_field.name, subname))
			return i;
	}
	return -1;
}
EXPORT_SYMBOL_GPL(lttng_get_context_index);

/*
 * Note: as we append context information, the pointer location may change.
 */
struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
{
	struct lttng_ctx_field *field;
	struct lttng_ctx *ctx;

	if (!*ctx_p) {
		*ctx_p = kzalloc(sizeof(struct lttng_ctx), GFP_KERNEL);
		if (!*ctx_p)
			return NULL;
		(*ctx_p)->largest_align = 1;
	}
	ctx = *ctx_p;
	if (ctx->nr_fields + 1 > ctx->allocated_fields) {
		struct lttng_ctx_field *new_fields;

		ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields);
		new_fields = lttng_kvzalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field), GFP_KERNEL);
		if (!new_fields)
			return NULL;
		if (ctx->fields)
			memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields);
		lttng_kvfree(ctx->fields);
		ctx->fields = new_fields;
	}
	field = &ctx->fields[ctx->nr_fields];
	ctx->nr_fields++;
	return field;
}
EXPORT_SYMBOL_GPL(lttng_append_context);

/*
 * lttng_context_update() should be called at least once between context
 * modification and trace start.
 */
void lttng_context_update(struct lttng_ctx *ctx)
{
	int i;
	size_t largest_align = 8;	/* in bits */

	for (i = 0; i < ctx->nr_fields; i++) {
		struct lttng_type *type;
		size_t field_align = 8;

		type = &ctx->fields[i].event_field.type;
		switch (type->atype) {
		case atype_integer:
			field_align = type->u.basic.integer.alignment;
			break;
		case atype_array:
		case atype_array_bitfield:
		{
			struct lttng_basic_type *btype;

			btype = &type->u.array.elem_type;
			switch (btype->atype) {
			case atype_integer:
				field_align = btype->u.basic.integer.alignment;
				break;
			case atype_string:
				break;

			case atype_array:
			case atype_sequence:
			case atype_array_bitfield:
			case atype_sequence_bitfield:
			case atype_struct:
			case atype_array_compound:
			case atype_sequence_compound:
			case atype_variant:
			default:
				WARN_ON_ONCE(1);
				break;
			}
			break;
		}
		case atype_sequence:
		case atype_sequence_bitfield:
		{
			struct lttng_basic_type *btype;

			btype = &type->u.sequence.length_type;
			switch (btype->atype) {
			case atype_integer:
				field_align = btype->u.basic.integer.alignment;
				break;

			case atype_string:
			case atype_array:
			case atype_sequence:
			case atype_array_bitfield:
			case atype_sequence_bitfield:
			case atype_struct:
			case atype_array_compound:
			case atype_sequence_compound:
			case atype_variant:
			default:
				WARN_ON_ONCE(1);
				break;
			}

			btype = &type->u.sequence.elem_type;
			switch (btype->atype) {
			case atype_integer:
				field_align = max_t(size_t,
					field_align,
					btype->u.basic.integer.alignment);
				break;

			case atype_string:
				break;

			case atype_array:
			case atype_sequence:
			case atype_array_bitfield:
			case atype_sequence_bitfield:
			case atype_struct:
			case atype_array_compound:
			case atype_sequence_compound:
			case atype_variant:
			default:
				WARN_ON_ONCE(1);
				break;
			}
			break;
		}
		case atype_string:
			break;

		case atype_struct:
		case atype_array_compound:
		case atype_sequence_compound:
		case atype_variant:
			break;

		case atype_enum:
		default:
			WARN_ON_ONCE(1);
			break;
		}
		largest_align = max_t(size_t, largest_align, field_align);
	}
	ctx->largest_align = largest_align >> 3;	/* bits to bytes */
}

/*
 * Remove last context field.
 */
void lttng_remove_context_field(struct lttng_ctx **ctx_p,
				struct lttng_ctx_field *field)
{
	struct lttng_ctx *ctx;

	ctx = *ctx_p;
	ctx->nr_fields--;
	WARN_ON_ONCE(&ctx->fields[ctx->nr_fields] != field);
	memset(&ctx->fields[ctx->nr_fields], 0, sizeof(struct lttng_ctx_field));
}
EXPORT_SYMBOL_GPL(lttng_remove_context_field);

void lttng_destroy_context(struct lttng_ctx *ctx)
{
	int i;

	if (!ctx)
		return;
	for (i = 0; i < ctx->nr_fields; i++) {
		if (ctx->fields[i].destroy)
			ctx->fields[i].destroy(&ctx->fields[i]);
	}
	lttng_kvfree(ctx->fields);
	kfree(ctx);
}

int lttng_context_init(void)
{
	int ret;

	ret = lttng_add_hostname_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_hostname_to_ctx");
	}
	ret = lttng_add_nice_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_nice_to_ctx");
	}
	ret = lttng_add_pid_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_pid_to_ctx");
	}
	ret = lttng_add_ppid_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_ppid_to_ctx");
	}
	ret = lttng_add_prio_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_prio_to_ctx");
	}
	ret = lttng_add_procname_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_procname_to_ctx");
	}
	ret = lttng_add_tid_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_tid_to_ctx");
	}
	ret = lttng_add_vppid_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_vppid_to_ctx");
	}
	ret = lttng_add_vtid_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_vtid_to_ctx");
	}
	ret = lttng_add_vpid_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_vpid_to_ctx");
	}
	ret = lttng_add_cpu_id_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_cpu_id_to_ctx");
	}
	ret = lttng_add_interruptible_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_interruptible_to_ctx");
	}
	ret = lttng_add_need_reschedule_to_ctx(&lttng_static_ctx);
	if (ret) {
		printk(KERN_WARNING "Cannot add context lttng_add_need_reschedule_to_ctx");
	}
	ret = lttng_add_preemptible_to_ctx(&lttng_static_ctx);
	if (ret && ret != -ENOSYS) {
		printk(KERN_WARNING "Cannot add context lttng_add_preemptible_to_ctx");
	}
	ret = lttng_add_migratable_to_ctx(&lttng_static_ctx);
	if (ret && ret != -ENOSYS) {
		printk(KERN_WARNING "Cannot add context lttng_add_migratable_to_ctx");
	}
	/* TODO: perf counters for filtering */
	return 0;
}

void lttng_context_exit(void)
{
	lttng_destroy_context(lttng_static_ctx);
	lttng_static_ctx = NULL;
}
Commit	Line	Data
9f36eaed MJ	1	/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
9f36eaed MJ	2	*
a90917c3	3	* lttng-context.c
2dccf128	4	*
2dccf128	5	* LTTng trace/channel/event context management.
17baffe2	6	*
886d51a3	7	* Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
2dccf128 MD	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/list.h>
	12	#include <linux/mutex.h>
	13	#include <linux/slab.h>
241ae9a8 MD	14	#include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_all() */
	15	#include <lttng-events.h>
	16	#include <lttng-tracer.h>
2dccf128	17
07dfc1d0 MD	18	/*
	19	* The filter implementation requires that two consecutive "get" for the
	20	* same context performed by the same thread return the same result.
	21	*/
	22
	23	/*
	24	* Static array of contexts, for $ctx filters.
	25	*/
	26	struct lttng_ctx *lttng_static_ctx;
	27
44252f0f MD	28	int lttng_find_context(struct lttng_ctx ctx, const char name)
	29	{
	30	unsigned int i;
	31
	32	for (i = 0; i < ctx->nr_fields; i++) {
4b58a8e4 MD	33	/* Skip allocated (but non-initialized) contexts */
	34	if (!ctx->fields[i].event_field.name)
	35	continue;
44252f0f MD	36	if (!strcmp(ctx->fields[i].event_field.name, name))
	37	return 1;
	38	}
	39	return 0;
	40	}
	41	EXPORT_SYMBOL_GPL(lttng_find_context);
	42
07dfc1d0 MD	43	int lttng_get_context_index(struct lttng_ctx ctx, const char name)
	44	{
	45	unsigned int i;
0451bcec	46	const char *subname;
07dfc1d0 MD	47
	48	if (!ctx)
	49	return -1;
0451bcec MD	50	if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) {
	51	subname = name + strlen("$ctx.");
	52	} else {
	53	subname = name;
	54	}
07dfc1d0 MD	55	for (i = 0; i < ctx->nr_fields; i++) {
	56	/* Skip allocated (but non-initialized) contexts */
	57	if (!ctx->fields[i].event_field.name)
	58	continue;
0451bcec	59	if (!strcmp(ctx->fields[i].event_field.name, subname))
07dfc1d0 MD	60	return i;
	61	}
	62	return -1;
	63	}
	64	EXPORT_SYMBOL_GPL(lttng_get_context_index);
	65
2001023e MD	66	/*
	67	* Note: as we append context information, the pointer location may change.
	68	*/
2dccf128 MD	69	struct lttng_ctx_field lttng_append_context(struct lttng_ctx *ctx_p)
	70	{
	71	struct lttng_ctx_field *field;
	72	struct lttng_ctx *ctx;
	73
	74	if (!*ctx_p) {
	75	*ctx_p = kzalloc(sizeof(struct lttng_ctx), GFP_KERNEL);
	76	if (!*ctx_p)
	77	return NULL;
a9dd15da	78	(*ctx_p)->largest_align = 1;
2dccf128 MD	79	}
	80	ctx = *ctx_p;
	81	if (ctx->nr_fields + 1 > ctx->allocated_fields) {
	82	struct lttng_ctx_field *new_fields;
	83
0f034e0f	84	ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields);
48f5e0b5	85	new_fields = lttng_kvzalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field), GFP_KERNEL);
2dccf128 MD	86	if (!new_fields)
	87	return NULL;
	88	if (ctx->fields)
77aefe99	89	memcpy(new_fields, ctx->fields, sizeof(ctx->fields) ctx->nr_fields);
48f5e0b5	90	lttng_kvfree(ctx->fields);
2dccf128 MD	91	ctx->fields = new_fields;
	92	}
	93	field = &ctx->fields[ctx->nr_fields];
	94	ctx->nr_fields++;
	95	return field;
	96	}
	97	EXPORT_SYMBOL_GPL(lttng_append_context);
	98
a9dd15da MD	99	/*
	100	* lttng_context_update() should be called at least once between context
	101	* modification and trace start.
	102	*/
	103	void lttng_context_update(struct lttng_ctx *ctx)
	104	{
	105	int i;
	106	size_t largest_align = 8; /* in bits */
	107
	108	for (i = 0; i < ctx->nr_fields; i++) {
	109	struct lttng_type *type;
	110	size_t field_align = 8;
	111
	112	type = &ctx->fields[i].event_field.type;
	113	switch (type->atype) {
	114	case atype_integer:
	115	field_align = type->u.basic.integer.alignment;
	116	break;
	117	case atype_array:
3834b99f	118	case atype_array_bitfield:
a9dd15da MD	119	{
	120	struct lttng_basic_type *btype;
	121
	122	btype = &type->u.array.elem_type;
	123	switch (btype->atype) {
	124	case atype_integer:
	125	field_align = btype->u.basic.integer.alignment;
	126	break;
	127	case atype_string:
	128	break;
	129
	130	case atype_array:
	131	case atype_sequence:
3834b99f MD	132	case atype_array_bitfield:
3834b99f MD	133	case atype_sequence_bitfield:
f513b2bf MD	134	case atype_struct:
	135	case atype_array_compound:
	136	case atype_sequence_compound:
65c85aa6	137	case atype_variant:
a9dd15da MD	138	default:
	139	WARN_ON_ONCE(1);
	140	break;
	141	}
	142	break;
	143	}
	144	case atype_sequence:
3834b99f	145	case atype_sequence_bitfield:
a9dd15da MD	146	{
	147	struct lttng_basic_type *btype;
	148
	149	btype = &type->u.sequence.length_type;
	150	switch (btype->atype) {
	151	case atype_integer:
	152	field_align = btype->u.basic.integer.alignment;
	153	break;
	154
	155	case atype_string:
	156	case atype_array:
	157	case atype_sequence:
3834b99f MD	158	case atype_array_bitfield:
3834b99f MD	159	case atype_sequence_bitfield:
f513b2bf MD	160	case atype_struct:
	161	case atype_array_compound:
	162	case atype_sequence_compound:
65c85aa6	163	case atype_variant:
a9dd15da MD	164	default:
	165	WARN_ON_ONCE(1);
	166	break;
	167	}
	168
	169	btype = &type->u.sequence.elem_type;
	170	switch (btype->atype) {
	171	case atype_integer:
	172	field_align = max_t(size_t,
	173	field_align,
	174	btype->u.basic.integer.alignment);
	175	break;
	176
	177	case atype_string:
	178	break;
	179
	180	case atype_array:
	181	case atype_sequence:
3834b99f MD	182	case atype_array_bitfield:
3834b99f MD	183	case atype_sequence_bitfield:
f513b2bf MD	184	case atype_struct:
	185	case atype_array_compound:
	186	case atype_sequence_compound:
65c85aa6	187	case atype_variant:
a9dd15da MD	188	default:
	189	WARN_ON_ONCE(1);
	190	break;
	191	}
	192	break;
	193	}
	194	case atype_string:
	195	break;
	196
f513b2bf MD	197	case atype_struct:
	198	case atype_array_compound:
	199	case atype_sequence_compound:
65c85aa6	200	case atype_variant:
f513b2bf MD	201	break;
f513b2bf MD	202
a9dd15da MD	203	case atype_enum:
	204	default:
	205	WARN_ON_ONCE(1);
	206	break;
	207	}
	208	largest_align = max_t(size_t, largest_align, field_align);
	209	}
	210	ctx->largest_align = largest_align >> 3; /* bits to bytes */
	211	}
	212
4cae220c MD	213	/*
	214	* Remove last context field.
	215	*/
8289661d MD	216	void lttng_remove_context_field(struct lttng_ctx **ctx_p,
	217	struct lttng_ctx_field *field)
	218	{
	219	struct lttng_ctx *ctx;
	220
	221	ctx = *ctx_p;
	222	ctx->nr_fields--;
4cae220c	223	WARN_ON_ONCE(&ctx->fields[ctx->nr_fields] != field);
8289661d MD	224	memset(&ctx->fields[ctx->nr_fields], 0, sizeof(struct lttng_ctx_field));
	225	}
	226	EXPORT_SYMBOL_GPL(lttng_remove_context_field);
	227
2dccf128 MD	228	void lttng_destroy_context(struct lttng_ctx *ctx)
	229	{
	230	int i;
	231
8070f5c0 MD	232	if (!ctx)
8070f5c0 MD	233	return;
9e7e4892 MD	234	for (i = 0; i < ctx->nr_fields; i++) {
	235	if (ctx->fields[i].destroy)
	236	ctx->fields[i].destroy(&ctx->fields[i]);
	237	}
48f5e0b5	238	lttng_kvfree(ctx->fields);
2dccf128 MD	239	kfree(ctx);
2dccf128 MD	240	}
07dfc1d0 MD	241
	242	int lttng_context_init(void)
	243	{
	244	int ret;
	245
f127e61e MD	246	ret = lttng_add_hostname_to_ctx(&lttng_static_ctx);
f127e61e MD	247	if (ret) {
38c4a82c	248	printk(KERN_WARNING "Cannot add context lttng_add_hostname_to_ctx");
f127e61e MD	249	}
f127e61e MD	250	ret = lttng_add_nice_to_ctx(&lttng_static_ctx);
07dfc1d0	251	if (ret) {
38c4a82c	252	printk(KERN_WARNING "Cannot add context lttng_add_nice_to_ctx");
07dfc1d0	253	}
07dfc1d0 MD	254	ret = lttng_add_pid_to_ctx(&lttng_static_ctx);
07dfc1d0 MD	255	if (ret) {
38c4a82c	256	printk(KERN_WARNING "Cannot add context lttng_add_pid_to_ctx");
07dfc1d0	257	}
f127e61e	258	ret = lttng_add_ppid_to_ctx(&lttng_static_ctx);
07dfc1d0	259	if (ret) {
38c4a82c	260	printk(KERN_WARNING "Cannot add context lttng_add_ppid_to_ctx");
07dfc1d0 MD	261	}
	262	ret = lttng_add_prio_to_ctx(&lttng_static_ctx);
	263	if (ret) {
38c4a82c	264	printk(KERN_WARNING "Cannot add context lttng_add_prio_to_ctx");
07dfc1d0	265	}
f127e61e	266	ret = lttng_add_procname_to_ctx(&lttng_static_ctx);
07dfc1d0	267	if (ret) {
38c4a82c	268	printk(KERN_WARNING "Cannot add context lttng_add_procname_to_ctx");
07dfc1d0 MD	269	}
	270	ret = lttng_add_tid_to_ctx(&lttng_static_ctx);
	271	if (ret) {
38c4a82c	272	printk(KERN_WARNING "Cannot add context lttng_add_tid_to_ctx");
07dfc1d0	273	}
f127e61e	274	ret = lttng_add_vppid_to_ctx(&lttng_static_ctx);
07dfc1d0	275	if (ret) {
38c4a82c	276	printk(KERN_WARNING "Cannot add context lttng_add_vppid_to_ctx");
07dfc1d0	277	}
f127e61e	278	ret = lttng_add_vtid_to_ctx(&lttng_static_ctx);
07dfc1d0	279	if (ret) {
38c4a82c	280	printk(KERN_WARNING "Cannot add context lttng_add_vtid_to_ctx");
07dfc1d0	281	}
f127e61e	282	ret = lttng_add_vpid_to_ctx(&lttng_static_ctx);
07dfc1d0	283	if (ret) {
38c4a82c	284	printk(KERN_WARNING "Cannot add context lttng_add_vpid_to_ctx");
07dfc1d0	285	}
b3699d90 MD	286	ret = lttng_add_cpu_id_to_ctx(&lttng_static_ctx);
	287	if (ret) {
	288	printk(KERN_WARNING "Cannot add context lttng_add_cpu_id_to_ctx");
	289	}
79150a49 JD	290	ret = lttng_add_interruptible_to_ctx(&lttng_static_ctx);
	291	if (ret) {
	292	printk(KERN_WARNING "Cannot add context lttng_add_interruptible_to_ctx");
	293	}
	294	ret = lttng_add_need_reschedule_to_ctx(&lttng_static_ctx);
	295	if (ret) {
	296	printk(KERN_WARNING "Cannot add context lttng_add_need_reschedule_to_ctx");
	297	}
79150a49	298	ret = lttng_add_preemptible_to_ctx(&lttng_static_ctx);
d0e59d6f	299	if (ret && ret != -ENOSYS) {
79150a49 JD	300	printk(KERN_WARNING "Cannot add context lttng_add_preemptible_to_ctx");
79150a49 JD	301	}
79150a49	302	ret = lttng_add_migratable_to_ctx(&lttng_static_ctx);
d0e59d6f	303	if (ret && ret != -ENOSYS) {
79150a49 JD	304	printk(KERN_WARNING "Cannot add context lttng_add_migratable_to_ctx");
79150a49 JD	305	}
f127e61e	306	/* TODO: perf counters for filtering */
07dfc1d0 MD	307	return 0;
	308	}
	309
	310	void lttng_context_exit(void)
	311	{
	312	lttng_destroy_context(lttng_static_ctx);
	313	lttng_static_ctx = NULL;
	314	}