[lttng-tools.git] / src / bin / lttng-sessiond / context.c

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _LGPL_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <urcu/list.h>

#include <common/error.h>
#include <common/sessiond-comm/sessiond-comm.h>

#include "context.h"
#include "kernel.h"
#include "ust-app.h"
#include "trace-ust.h"
#include "agent.h"

/*
 * Add kernel context to all channel.
 */
static int add_kctx_all_channels(struct ltt_kernel_session *ksession,
		struct ltt_kernel_context *kctx)
{
	int ret;
	struct ltt_kernel_channel *kchan;

	assert(ksession);
	assert(kctx);

	DBG("Adding kernel context to all channels");

	/* Go over all channels */
	cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
		ret = kernel_add_channel_context(kchan, kctx);
		if (ret != 0) {
			goto error;
		}
	}

	ret = LTTNG_OK;

error:
	return ret;
}

/*
 * Add kernel context to a specific channel.
 */
static int add_kctx_to_channel(struct ltt_kernel_context *kctx,
		struct ltt_kernel_channel *kchan)
{
	int ret;

	assert(kchan);
	assert(kctx);

	DBG("Add kernel context to channel '%s'", kchan->channel->name);

	ret = kernel_add_channel_context(kchan, kctx);
	if (ret != 0) {
		goto error;
	}

	ret = LTTNG_OK;

error:
	return ret;
}

/*
 * Add UST context to channel.
 */
static int add_uctx_to_channel(struct ltt_ust_session *usess,
		enum lttng_domain_type domain,
		struct ltt_ust_channel *uchan, struct lttng_event_context *ctx)
{
	int ret;
	struct ltt_ust_context *uctx = NULL;

	assert(usess);
	assert(uchan);
	assert(ctx);

	/* Check if context is duplicate */
	cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
		if (trace_ust_match_context(uctx, ctx)) {
			ret = -EEXIST;
			goto duplicate;
		}
	}
	uctx = NULL;

	switch (domain) {
	case LTTNG_DOMAIN_JUL:
	case LTTNG_DOMAIN_LOG4J:
	{
		struct agent *agt;

		if (ctx->ctx != LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
			/* Other contexts are not needed by the agent. */
			break;
		}
		agt = trace_ust_find_agent(usess, domain);

		if (!agt) {
			agt = agent_create(domain);
			if (!agt) {
				ret = LTTNG_ERR_NOMEM;
				goto error;
			}
			agent_add(agt, usess->agents);
		}
		ret = agent_add_context(ctx, agt);
		if (ret != LTTNG_OK) {
			goto error;
		}

		ret = agent_enable_context(ctx, domain);
		if (ret != LTTNG_OK) {
			goto error;
		}
		break;
	}
	case LTTNG_DOMAIN_UST:
		break;
	default:
		assert(0);
	}

	/* Create ltt UST context */
	uctx = trace_ust_create_context(ctx);
	if (uctx == NULL) {
		ret = -EINVAL;
		goto error;
	}

	ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx);
	if (ret < 0) {
		goto error;
	}

	rcu_read_lock();

	/* Add ltt UST context node to ltt UST channel */
	lttng_ht_add_ulong(uchan->ctx, &uctx->node);
	rcu_read_unlock();
	cds_list_add_tail(&uctx->list, &uchan->ctx_list);

	DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name);

	return 0;

error:
	free(uctx);
duplicate:
	return ret;
}

/*
 * Add kernel context to tracer.
 */
int context_kernel_add(struct ltt_kernel_session *ksession,
		struct lttng_event_context *ctx, char *channel_name)
{
	int ret;
	struct ltt_kernel_channel *kchan;
	struct ltt_kernel_context *kctx;

	assert(ksession);
	assert(ctx);
	assert(channel_name);

	kctx = trace_kernel_create_context(NULL);
	if (!kctx) {
		ret = LTTNG_ERR_NOMEM;
		goto error;
	}

	/* Setup kernel context structure */
	switch (ctx->ctx) {
	case LTTNG_EVENT_CONTEXT_PID:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PID;
		break;
	case LTTNG_EVENT_CONTEXT_PROCNAME:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PROCNAME;
		break;
	case LTTNG_EVENT_CONTEXT_PRIO:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PRIO;
		break;
	case LTTNG_EVENT_CONTEXT_NICE:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NICE;
		break;
	case LTTNG_EVENT_CONTEXT_VPID:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPID;
		break;
	case LTTNG_EVENT_CONTEXT_TID:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_TID;
		break;
	case LTTNG_EVENT_CONTEXT_VTID:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VTID;
		break;
	case LTTNG_EVENT_CONTEXT_PPID:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PPID;
		break;
	case LTTNG_EVENT_CONTEXT_VPPID:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPPID;
		break;
	case LTTNG_EVENT_CONTEXT_HOSTNAME:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_HOSTNAME;
		break;
	case LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER:
	case LTTNG_EVENT_CONTEXT_PERF_COUNTER:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER;
		break;
	case LTTNG_EVENT_CONTEXT_INTERRUPTIBLE:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE;
		break;
	case LTTNG_EVENT_CONTEXT_PREEMPTIBLE:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PREEMPTIBLE;
		break;
	case LTTNG_EVENT_CONTEXT_NEED_RESCHEDULE:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE;
		break;
	case LTTNG_EVENT_CONTEXT_MIGRATABLE:
		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_MIGRATABLE;
		break;
	default:
		ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
		goto error;
	}

	kctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
	kctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
	strncpy(kctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
			LTTNG_SYMBOL_NAME_LEN);
	kctx->ctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';

	if (*channel_name == '\0') {
		ret = add_kctx_all_channels(ksession, kctx);
		if (ret != LTTNG_OK) {
			goto error;
		}
	} else {
		/* Get kernel channel */
		kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
		if (kchan == NULL) {
			ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
			goto error;
		}

		ret = add_kctx_to_channel(kctx, kchan);
		if (ret != LTTNG_OK) {
			goto error;
		}
	}

	return LTTNG_OK;

error:
	if (kctx) {
		trace_kernel_destroy_context(kctx);
	}
	return ret;
}

/*
 * Add UST context to tracer.
 */
int context_ust_add(struct ltt_ust_session *usess,
		enum lttng_domain_type domain, struct lttng_event_context *ctx,
		char *channel_name)
{
	int ret = LTTNG_OK;
	struct lttng_ht_iter iter;
	struct lttng_ht *chan_ht;
	struct ltt_ust_channel *uchan = NULL;

	assert(usess);
	assert(ctx);
	assert(channel_name);

	rcu_read_lock();

	chan_ht = usess->domain_global.channels;

	/* Get UST channel if defined */
	if (channel_name[0] != '\0') {
		uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
		if (uchan == NULL) {
			ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
			goto error;
		}
	}

	if (uchan) {
		/* Add ctx to channel */
		ret = add_uctx_to_channel(usess, domain, uchan, ctx);
	} else {
		rcu_read_lock();
		/* Add ctx all events, all channels */
		cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
			ret = add_uctx_to_channel(usess, domain, uchan, ctx);
			if (ret < 0) {
				ERR("Failed to add context to channel %s",
						uchan->name);
				continue;
			}
		}
		rcu_read_unlock();
	}

	switch (ret) {
	case -EEXIST:
		ret = LTTNG_ERR_UST_CONTEXT_EXIST;
		break;
	case -ENOMEM:
		ret = LTTNG_ERR_FATAL;
		break;
	case -EINVAL:
		ret = LTTNG_ERR_UST_CONTEXT_INVAL;
		break;
	case -ENOSYS:
		ret = LTTNG_ERR_UNKNOWN_DOMAIN;
		break;
	default:
		ret = LTTNG_OK;
		break;
	}

error:
	rcu_read_unlock();
	return ret;
}
Commit	Line	Data
b579acd9	1	/*
bdf64013 JG	2	* Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
bdf64013 JG	3	* Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
b579acd9	4	*
d14d33bf AM	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License, version 2 only,
	7	* as published by the Free Software Foundation.
b579acd9	8	*
d14d33bf AM	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
b579acd9	13	*
d14d33bf AM	14	* You should have received a copy of the GNU General Public License along
	15	* with this program; if not, write to the Free Software Foundation, Inc.,
	16	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
b579acd9 DG	17	*/
b579acd9 DG	18
6c1c0768	19	#define _LGPL_SOURCE
b579acd9 DG	20	#include <stdio.h>
	21	#include <stdlib.h>
	22	#include <string.h>
	23	#include <unistd.h>
54d01ffb	24	#include <urcu/list.h>
1e307fab	25
db758600	26	#include <common/error.h>
10a8a223	27	#include <common/sessiond-comm/sessiond-comm.h>
b579acd9	28
b579acd9	29	#include "context.h"
4771f025	30	#include "kernel.h"
55cc08a6	31	#include "ust-app.h"
34378f76	32	#include "trace-ust.h"
bdf64013	33	#include "agent.h"
b579acd9	34
b579acd9 DG	35	/*
b579acd9 DG	36	* Add kernel context to all channel.
b579acd9 DG	37	*/
b579acd9 DG	38	static int add_kctx_all_channels(struct ltt_kernel_session *ksession,
645328ae	39	struct ltt_kernel_context *kctx)
b579acd9	40	{
601d5acf	41	int ret;
b579acd9 DG	42	struct ltt_kernel_channel *kchan;
b579acd9 DG	43
0525e9ae DG	44	assert(ksession);
	45	assert(kctx);
	46
601d5acf	47	DBG("Adding kernel context to all channels");
b579acd9 DG	48
	49	/* Go over all channels */
	50	cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
601d5acf	51	ret = kernel_add_channel_context(kchan, kctx);
1ae5e83e	52	if (ret != 0) {
601d5acf	53	goto error;
b579acd9 DG	54	}
	55	}
	56
f73fabfd	57	ret = LTTNG_OK;
b579acd9 DG	58
	59	error:
	60	return ret;
	61	}
	62
	63	/*
	64	* Add kernel context to a specific channel.
b579acd9	65	*/
645328ae	66	static int add_kctx_to_channel(struct ltt_kernel_context *kctx,
601d5acf	67	struct ltt_kernel_channel *kchan)
b579acd9	68	{
601d5acf	69	int ret;
b579acd9	70
0525e9ae DG	71	assert(kchan);
	72	assert(kctx);
	73
601d5acf	74	DBG("Add kernel context to channel '%s'", kchan->channel->name);
b579acd9	75
601d5acf	76	ret = kernel_add_channel_context(kchan, kctx);
1ae5e83e	77	if (ret != 0) {
b579acd9 DG	78	goto error;
	79	}
	80
f73fabfd	81	ret = LTTNG_OK;
b579acd9 DG	82
	83	error:
	84	return ret;
	85	}
	86
6b79ed20 DG	87	/*
	88	* Add UST context to channel.
	89	*/
4ce7709b JG	90	static int add_uctx_to_channel(struct ltt_ust_session *usess,
4ce7709b JG	91	enum lttng_domain_type domain,
6b79ed20 DG	92	struct ltt_ust_channel uchan, struct lttng_event_context ctx)
	93	{
	94	int ret;
bdf64013	95	struct ltt_ust_context *uctx = NULL;
6b79ed20	96
0525e9ae DG	97	assert(usess);
	98	assert(uchan);
	99	assert(ctx);
	100
aa3514e9 MD	101	/* Check if context is duplicate */
	102	cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
	103	if (trace_ust_match_context(uctx, ctx)) {
	104	ret = -EEXIST;
	105	goto duplicate;
	106	}
	107	}
bdf64013 JG	108	uctx = NULL;
	109
	110	switch (domain) {
	111	case LTTNG_DOMAIN_JUL:
	112	case LTTNG_DOMAIN_LOG4J:
	113	{
442f8c07 JG	114	struct agent *agt;
	115
	116	if (ctx->ctx != LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
	117	/* Other contexts are not needed by the agent. */
	118	break;
	119	}
	120	agt = trace_ust_find_agent(usess, domain);
bdf64013 JG	121
	122	if (!agt) {
	123	agt = agent_create(domain);
	124	if (!agt) {
	125	ret = LTTNG_ERR_NOMEM;
	126	goto error;
	127	}
	128	agent_add(agt, usess->agents);
	129	}
	130	ret = agent_add_context(ctx, agt);
	131	if (ret != LTTNG_OK) {
	132	goto error;
	133	}
	134
	135	ret = agent_enable_context(ctx, domain);
	136	if (ret != LTTNG_OK) {
	137	goto error;
	138	}
	139	break;
	140	}
	141	case LTTNG_DOMAIN_UST:
	142	break;
	143	default:
	144	assert(0);
	145	}
aa3514e9	146
6b79ed20 DG	147	/* Create ltt UST context */
	148	uctx = trace_ust_create_context(ctx);
	149	if (uctx == NULL) {
727d5404	150	ret = -EINVAL;
6b79ed20 DG	151	goto error;
	152	}
	153
c0c66aec JG	154	ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx);
c0c66aec JG	155	if (ret < 0) {
727d5404 DG	156	goto error;
	157	}
	158
e7fe706f DG	159	rcu_read_lock();
e7fe706f DG	160
6b79ed20	161	/* Add ltt UST context node to ltt UST channel */
aa3514e9	162	lttng_ht_add_ulong(uchan->ctx, &uctx->node);
e7fe706f	163	rcu_read_unlock();
31746f93	164	cds_list_add_tail(&uctx->list, &uchan->ctx_list);
6b79ed20	165
727d5404 DG	166	DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name);
	167
	168	return 0;
6b79ed20 DG	169
	170	error:
	171	free(uctx);
aa3514e9	172	duplicate:
6b79ed20 DG	173	return ret;
	174	}
	175
b579acd9 DG	176	/*
	177	* Add kernel context to tracer.
	178	*/
54d01ffb	179	int context_kernel_add(struct ltt_kernel_session *ksession,
601d5acf	180	struct lttng_event_context ctx, char channel_name)
b579acd9 DG	181	{
	182	int ret;
	183	struct ltt_kernel_channel *kchan;
645328ae	184	struct ltt_kernel_context *kctx;
54d01ffb	185
0525e9ae DG	186	assert(ksession);
	187	assert(ctx);
	188	assert(channel_name);
	189
645328ae DG	190	kctx = trace_kernel_create_context(NULL);
	191	if (!kctx) {
	192	ret = LTTNG_ERR_NOMEM;
	193	goto error;
	194	}
	195
54d01ffb	196	/* Setup kernel context structure */
9197c5c4 MD	197	switch (ctx->ctx) {
9197c5c4 MD	198	case LTTNG_EVENT_CONTEXT_PID:
645328ae	199	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PID;
9197c5c4	200	break;
9197c5c4	201	case LTTNG_EVENT_CONTEXT_PROCNAME:
645328ae	202	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PROCNAME;
9197c5c4 MD	203	break;
9197c5c4 MD	204	case LTTNG_EVENT_CONTEXT_PRIO:
645328ae	205	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PRIO;
9197c5c4 MD	206	break;
9197c5c4 MD	207	case LTTNG_EVENT_CONTEXT_NICE:
645328ae	208	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NICE;
9197c5c4 MD	209	break;
9197c5c4 MD	210	case LTTNG_EVENT_CONTEXT_VPID:
645328ae	211	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPID;
9197c5c4 MD	212	break;
9197c5c4 MD	213	case LTTNG_EVENT_CONTEXT_TID:
645328ae	214	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_TID;
9197c5c4 MD	215	break;
9197c5c4 MD	216	case LTTNG_EVENT_CONTEXT_VTID:
645328ae	217	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VTID;
9197c5c4 MD	218	break;
9197c5c4 MD	219	case LTTNG_EVENT_CONTEXT_PPID:
645328ae	220	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PPID;
9197c5c4 MD	221	break;
9197c5c4 MD	222	case LTTNG_EVENT_CONTEXT_VPPID:
645328ae	223	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPPID;
9197c5c4	224	break;
54773d68	225	case LTTNG_EVENT_CONTEXT_HOSTNAME:
645328ae	226	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_HOSTNAME;
54773d68	227	break;
aa3514e9 MD	228	case LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER:
aa3514e9 MD	229	case LTTNG_EVENT_CONTEXT_PERF_COUNTER:
645328ae	230	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PERF_CPU_COUNTER;
aa3514e9	231	break;
1ae5e83e JD	232	case LTTNG_EVENT_CONTEXT_INTERRUPTIBLE:
	233	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE;
	234	break;
	235	case LTTNG_EVENT_CONTEXT_PREEMPTIBLE:
	236	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PREEMPTIBLE;
	237	break;
	238	case LTTNG_EVENT_CONTEXT_NEED_RESCHEDULE:
	239	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE;
	240	break;
	241	case LTTNG_EVENT_CONTEXT_MIGRATABLE:
	242	kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_MIGRATABLE;
	243	break;
9197c5c4	244	default:
fc7324e8 DG	245	ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
fc7324e8 DG	246	goto error;
9197c5c4 MD	247	}
9197c5c4 MD	248
645328ae DG	249	kctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
	250	kctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
	251	strncpy(kctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
54d01ffb	252	LTTNG_SYMBOL_NAME_LEN);
645328ae	253	kctx->ctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
b579acd9	254
9d035200	255	if (*channel_name == '\0') {
645328ae	256	ret = add_kctx_all_channels(ksession, kctx);
f73fabfd	257	if (ret != LTTNG_OK) {
b579acd9 DG	258	goto error;
	259	}
	260	} else {
	261	/* Get kernel channel */
62499ad6	262	kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
b579acd9	263	if (kchan == NULL) {
f73fabfd	264	ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
b579acd9 DG	265	goto error;
	266	}
	267
645328ae	268	ret = add_kctx_to_channel(kctx, kchan);
f73fabfd	269	if (ret != LTTNG_OK) {
b579acd9 DG	270	goto error;
	271	}
	272	}
	273
fc7324e8	274	return LTTNG_OK;
b579acd9 DG	275
b579acd9 DG	276	error:
fc7324e8 DG	277	if (kctx) {
	278	trace_kernel_destroy_context(kctx);
	279	}
b579acd9 DG	280	return ret;
b579acd9 DG	281	}
2bdd86d4 MD	282
2bdd86d4 MD	283	/*
55cc08a6	284	* Add UST context to tracer.
2bdd86d4	285	*/
4ce7709b JG	286	int context_ust_add(struct ltt_ust_session *usess,
	287	enum lttng_domain_type domain, struct lttng_event_context *ctx,
	288	char *channel_name)
2bdd86d4	289	{
601d5acf	290	int ret = LTTNG_OK;
442359c0	291	struct lttng_ht_iter iter;
bec39940	292	struct lttng_ht *chan_ht;
55cc08a6	293	struct ltt_ust_channel *uchan = NULL;
2bdd86d4	294
0525e9ae DG	295	assert(usess);
	296	assert(ctx);
	297	assert(channel_name);
	298
2223c96f DG	299	rcu_read_lock();
2223c96f DG	300
f5501dad	301	chan_ht = usess->domain_global.channels;
2bdd86d4	302
55cc08a6	303	/* Get UST channel if defined */
9f9ee9c9	304	if (channel_name[0] != '\0') {
55cc08a6 DG	305	uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
55cc08a6 DG	306	if (uchan == NULL) {
f73fabfd	307	ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
2bdd86d4 MD	308	goto error;
2bdd86d4 MD	309	}
55cc08a6 DG	310	}
55cc08a6 DG	311
601d5acf DG	312	if (uchan) {
601d5acf DG	313	/* Add ctx to channel */
6b79ed20	314	ret = add_uctx_to_channel(usess, domain, uchan, ctx);
601d5acf	315	} else {
e7fe706f	316	rcu_read_lock();
601d5acf	317	/* Add ctx all events, all channels */
bec39940	318	cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
6b79ed20	319	ret = add_uctx_to_channel(usess, domain, uchan, ctx);
55cc08a6	320	if (ret < 0) {
9589be74 JG	321	ERR("Failed to add context to channel %s",
9589be74 JG	322	uchan->name);
55cc08a6 DG	323	continue;
55cc08a6 DG	324	}
2bdd86d4	325	}
e7fe706f	326	rcu_read_unlock();
55cc08a6	327	}
2bdd86d4	328
55cc08a6 DG	329	switch (ret) {
55cc08a6 DG	330	case -EEXIST:
f73fabfd	331	ret = LTTNG_ERR_UST_CONTEXT_EXIST;
727d5404	332	break;
55cc08a6	333	case -ENOMEM:
f73fabfd	334	ret = LTTNG_ERR_FATAL;
727d5404 DG	335	break;
727d5404 DG	336	case -EINVAL:
f73fabfd	337	ret = LTTNG_ERR_UST_CONTEXT_INVAL;
727d5404 DG	338	break;
727d5404 DG	339	case -ENOSYS:
f73fabfd	340	ret = LTTNG_ERR_UNKNOWN_DOMAIN;
727d5404 DG	341	break;
727d5404 DG	342	default:
f73fabfd	343	ret = LTTNG_OK;
727d5404	344	break;
2bdd86d4 MD	345	}
2bdd86d4 MD	346
2bdd86d4	347	error:
2223c96f	348	rcu_read_unlock();
2bdd86d4 MD	349	return ret;
2bdd86d4 MD	350	}