X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcontext.c;h=621c0b9fb53cfa88a56abc5b6737b52aee8eaa56;hp=1bf3c67680ed9d1f568c5d8b2b6455fa9d33edff;hb=d37ac3cdc4fe21f117edfb829db4d0eb7cf914a1;hpb=f73fabfda365d22e7dd180fb1614e37c446fbd9e

diff --git a/src/bin/lttng-sessiond/context.c b/src/bin/lttng-sessiond/context.c
index 1bf3c6768..621c0b9fb 100644
--- a/src/bin/lttng-sessiond/context.c
+++ b/src/bin/lttng-sessiond/context.c
@@ -1,21 +1,12 @@
 /*
- * Copyright (C)  2011 - David Goulet <david.goulet@polymtl.ca>
+ * 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.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * 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 _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -29,118 +20,69 @@
 #include "kernel.h"
 #include "ust-app.h"
 #include "trace-ust.h"
-
-/*
- * Add kernel context to an event of a specific channel.
- */
-static int add_kctx_to_event(struct lttng_kernel_context *kctx,
-		struct ltt_kernel_channel *kchan, char *event_name)
-{
-	int ret, found = 0;
-	struct ltt_kernel_event *kevent;
-
-	DBG("Add kernel context to event %s", event_name);
-
-	kevent = trace_kernel_get_event_by_name(event_name, kchan);
-	if (kevent != NULL) {
-		ret = kernel_add_event_context(kevent, kctx);
-		if (ret < 0) {
-			goto error;
-		}
-		found = 1;
-	}
-
-	ret = found;
-
-error:
-	return ret;
-}
+#include "agent.h"
 
 /*
  * Add kernel context to all channel.
  *
- * If event_name is specified, add context to event instead.
+ * Assumes the ownership of kctx.
  */
 static int add_kctx_all_channels(struct ltt_kernel_session *ksession,
-		struct lttng_kernel_context *kctx, char *event_name)
+		struct ltt_kernel_context *kctx)
 {
-	int ret, no_event = 0, found = 0;
+	int ret;
 	struct ltt_kernel_channel *kchan;
 
-	if (strlen(event_name) == 0) {
-		no_event = 1;
-	}
+	assert(ksession);
+	assert(kctx);
 
-	DBG("Adding kernel context to all channels (event: %s)", event_name);
+	DBG("Adding kernel context to all channels");
 
 	/* Go over all channels */
 	cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
-		if (no_event) {
-			ret = kernel_add_channel_context(kchan, kctx);
-			if (ret < 0) {
-				ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
-				goto error;
-			}
-		} else {
-			ret = add_kctx_to_event(kctx, kchan, event_name);
-			if (ret < 0) {
-				ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
-				goto error;
-			} else if (ret == 1) {
-				/* Event found and context added */
-				found = 1;
-				break;
-			}
+		struct ltt_kernel_context *kctx_copy;
+
+		kctx_copy = trace_kernel_copy_context(kctx);
+		if (!kctx_copy) {
+			PERROR("zmalloc ltt_kernel_context");
+			ret = -LTTNG_ERR_NOMEM;
+			goto error;
 		}
-	}
 
-	if (!found && !no_event) {
-		ret = LTTNG_ERR_NO_EVENT;
-		goto error;
+		/* Ownership of kctx_copy is transferred to the callee. */
+		ret = kernel_add_channel_context(kchan, kctx_copy);
+		kctx_copy = NULL;
+		if (ret != 0) {
+			goto error;
+		}
 	}
 
 	ret = LTTNG_OK;
 
 error:
+	trace_kernel_destroy_context(kctx);
 	return ret;
 }
 
 /*
  * Add kernel context to a specific channel.
  *
- * If event_name is specified, add context to that event.
+ * Assumes the ownership of kctx.
  */
-static int add_kctx_to_channel(struct lttng_kernel_context *kctx,
-		struct ltt_kernel_channel *kchan, char *event_name)
+static int add_kctx_to_channel(struct ltt_kernel_context *kctx,
+		struct ltt_kernel_channel *kchan)
 {
-	int ret, no_event = 0, found = 0;
-
-	if (strlen(event_name) == 0) {
-		no_event = 1;
-	}
+	int ret;
 
-	DBG("Add kernel context to channel '%s', event '%s'",
-			kchan->channel->name, event_name);
+	assert(kchan);
+	assert(kctx);
 
-	if (no_event) {
-		ret = kernel_add_channel_context(kchan, kctx);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
-			goto error;
-		}
-	} else {
-		ret = add_kctx_to_event(kctx, kchan, event_name);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
-			goto error;
-		} else if (ret == 1) {
-			/* Event found and context added */
-			found = 1;
-		}
-	}
+	DBG("Add kernel context to channel '%s'", kchan->channel->name);
 
-	if (!found && !no_event) {
-		ret = LTTNG_ERR_NO_EVENT;
+	/* Ownership of kctx is transferred to the callee. */
+	ret = kernel_add_channel_context(kchan, kctx);
+	kctx = NULL;
+	if (ret != 0) {
 		goto error;
 	}
 
@@ -153,102 +95,91 @@ error:
 /*
  * Add UST context to channel.
  */
-static int add_uctx_to_channel(struct ltt_ust_session *usess, int domain,
-		struct ltt_ust_channel *uchan, struct lttng_event_context *ctx)
+static int add_uctx_to_channel(struct ltt_ust_session *usess,
+		enum lttng_domain_type domain,
+		struct ltt_ust_channel *uchan,
+		const struct lttng_event_context *ctx)
 {
 	int ret;
-	struct ltt_ust_context *uctx;
-	struct lttng_ht_iter iter;
-	struct lttng_ht_node_ulong *uctx_node;
+	struct ltt_ust_context *uctx = NULL;
 
-	/* Create ltt UST context */
-	uctx = trace_ust_create_context(ctx);
-	if (uctx == NULL) {
-		ret = -EINVAL;
-		goto error;
+	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 = LTTNG_ERR_UST_CONTEXT_EXIST;
+			goto duplicate;
+		}
 	}
+	uctx = NULL;
 
 	switch (domain) {
-	case LTTNG_DOMAIN_UST:
-		ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx);
-		if (ret < 0) {
+	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;
-	default:
-		ret = -ENOSYS;
-		goto error;
 	}
-
-	/* Lookup context before adding it */
-	lttng_ht_lookup(uchan->ctx, (void *)((unsigned long)uctx->ctx.ctx), &iter);
-	uctx_node = lttng_ht_iter_get_node_ulong(&iter);
-	if (uctx_node != NULL) {
-		ret = -EEXIST;
-		goto error;
+	case LTTNG_DOMAIN_UST:
+		break;
+	default:
+		assert(0);
 	}
 
-	/* Add ltt UST context node to ltt UST channel */
-	lttng_ht_add_unique_ulong(uchan->ctx, &uctx->node);
-
-	DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name);
-
-	return 0;
-
-error:
-	free(uctx);
-	return ret;
-}
-
-/*
- * Add UST context to event.
- */
-static int add_uctx_to_event(struct ltt_ust_session *usess, int domain,
-		struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent,
-		struct lttng_event_context *ctx)
-{
-	int ret;
-	struct ltt_ust_context *uctx;
-	struct lttng_ht_iter iter;
-	struct lttng_ht_node_ulong *uctx_node;
-
 	/* Create ltt UST context */
 	uctx = trace_ust_create_context(ctx);
 	if (uctx == NULL) {
-		/* Context values are invalid. */
-		ret = -EINVAL;
+		ret = LTTNG_ERR_UST_CONTEXT_INVAL;
 		goto error;
 	}
 
-	switch (domain) {
-	case LTTNG_DOMAIN_UST:
-		ret = ust_app_add_ctx_event_glb(usess, uchan, uevent, uctx);
-		if (ret < 0) {
-			goto error;
-		}
-		break;
-	default:
-		ret = -ENOSYS;
-		goto error;
+	/* Add ltt UST context node to ltt UST channel */
+	lttng_ht_add_ulong(uchan->ctx, &uctx->node);
+	cds_list_add_tail(&uctx->list, &uchan->ctx_list);
+
+	if (!usess->active) {
+		goto end;
 	}
 
-	/* Lookup context before adding it */
-	lttng_ht_lookup(uevent->ctx, (void *)((unsigned long)uctx->ctx.ctx), &iter);
-	uctx_node = lttng_ht_iter_get_node_ulong(&iter);
-	if (uctx_node != NULL) {
-		ret = -EEXIST;
+	ret = ust_app_add_ctx_channel_glb(usess, uchan, uctx);
+	if (ret < 0) {
 		goto error;
 	}
-
-	/* Add ltt UST context node to ltt UST event */
-	lttng_ht_add_unique_ulong(uevent->ctx, &uctx->node);
-
-	DBG("Context UST %d added to event %s", uctx->ctx.ctx, uevent->attr.name);
+end:
+	DBG("Context UST %d added to channel %s", uctx->ctx.ctx, uchan->name);
 
 	return 0;
 
 error:
 	free(uctx);
+duplicate:
 	return ret;
 }
 
@@ -256,60 +187,151 @@ error:
  * Add kernel context to tracer.
  */
 int context_kernel_add(struct ltt_kernel_session *ksession,
-		struct lttng_event_context *ctx, char *event_name,
-		char *channel_name)
+		const struct lttng_event_context *ctx, char *channel_name)
 {
 	int ret;
 	struct ltt_kernel_channel *kchan;
-	struct lttng_kernel_context kctx;
+	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 = LTTNG_KERNEL_CONTEXT_PID;
-		break;
-	case LTTNG_EVENT_CONTEXT_PERF_COUNTER:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_PERF_COUNTER;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PID;
 		break;
 	case LTTNG_EVENT_CONTEXT_PROCNAME:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_PROCNAME;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PROCNAME;
 		break;
 	case LTTNG_EVENT_CONTEXT_PRIO:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_PRIO;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PRIO;
 		break;
 	case LTTNG_EVENT_CONTEXT_NICE:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_NICE;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NICE;
 		break;
 	case LTTNG_EVENT_CONTEXT_VPID:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_VPID;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPID;
 		break;
 	case LTTNG_EVENT_CONTEXT_TID:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_TID;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_TID;
 		break;
 	case LTTNG_EVENT_CONTEXT_VTID:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_VTID;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VTID;
 		break;
 	case LTTNG_EVENT_CONTEXT_PPID:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_PPID;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PPID;
 		break;
 	case LTTNG_EVENT_CONTEXT_VPPID:
-		kctx.ctx = LTTNG_KERNEL_CONTEXT_VPPID;
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VPPID;
 		break;
 	case LTTNG_EVENT_CONTEXT_HOSTNAME:
-		kctx.ctx = LTTNG_KERNEL_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;
+	case LTTNG_EVENT_CONTEXT_CALLSTACK_KERNEL:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL;
+		break;
+	case LTTNG_EVENT_CONTEXT_CALLSTACK_USER:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_CALLSTACK_USER;
+		break;
+	case LTTNG_EVENT_CONTEXT_CGROUP_NS:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_CGROUP_NS;
+		break;
+	case LTTNG_EVENT_CONTEXT_IPC_NS:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_IPC_NS;
+		break;
+	case LTTNG_EVENT_CONTEXT_MNT_NS:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_MNT_NS;
+		break;
+	case LTTNG_EVENT_CONTEXT_NET_NS:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_NET_NS;
+		break;
+	case LTTNG_EVENT_CONTEXT_PID_NS:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_PID_NS;
+		break;
+	case LTTNG_EVENT_CONTEXT_TIME_NS:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_TIME_NS;
+		break;
+	case LTTNG_EVENT_CONTEXT_USER_NS:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_USER_NS;
+		break;
+	case LTTNG_EVENT_CONTEXT_UTS_NS:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_UTS_NS;
+		break;
+	case LTTNG_EVENT_CONTEXT_UID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_UID;
+		break;
+	case LTTNG_EVENT_CONTEXT_EUID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_EUID;
+		break;
+	case LTTNG_EVENT_CONTEXT_SUID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_SUID;
+		break;
+	case LTTNG_EVENT_CONTEXT_GID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_GID;
+		break;
+	case LTTNG_EVENT_CONTEXT_EGID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_EGID;
+		break;
+	case LTTNG_EVENT_CONTEXT_SGID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_SGID;
+		break;
+	case LTTNG_EVENT_CONTEXT_VUID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VUID;
+		break;
+	case LTTNG_EVENT_CONTEXT_VEUID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VEUID;
+		break;
+	case LTTNG_EVENT_CONTEXT_VSUID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VSUID;
+		break;
+	case LTTNG_EVENT_CONTEXT_VGID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VGID;
+		break;
+	case LTTNG_EVENT_CONTEXT_VEGID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VEGID;
+		break;
+	case LTTNG_EVENT_CONTEXT_VSGID:
+		kctx->ctx.ctx = LTTNG_KERNEL_CONTEXT_VSGID;
 		break;
 	default:
-		return LTTNG_ERR_KERN_CONTEXT_FAIL;
+		ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
+		goto error;
 	}
 
-	kctx.u.perf_counter.type = ctx->u.perf_counter.type;
-	kctx.u.perf_counter.config = ctx->u.perf_counter.config;
-	strncpy(kctx.u.perf_counter.name, ctx->u.perf_counter.name,
+	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.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
+	kctx->ctx.u.perf_counter.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 
-	if (strlen(channel_name) == 0) {
-		ret = add_kctx_all_channels(ksession, &kctx, event_name);
+	if (*channel_name == '\0') {
+		ret = add_kctx_all_channels(ksession, kctx);
+		/* Ownership of kctx is transferred to the callee. */
+		kctx = NULL;
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -321,7 +343,9 @@ int context_kernel_add(struct ltt_kernel_session *ksession,
 			goto error;
 		}
 
-		ret = add_kctx_to_channel(&kctx, kchan, event_name);
+		ret = add_kctx_to_channel(kctx, kchan);
+		/* Ownership of kctx is transferred to the callee. */
+		kctx = NULL;
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -330,47 +354,35 @@ int context_kernel_add(struct ltt_kernel_session *ksession,
 	ret = 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, int domain,
-		struct lttng_event_context *ctx, char *event_name,
+int context_ust_add(struct ltt_ust_session *usess,
+		enum lttng_domain_type domain,
+		const struct lttng_event_context *ctx,
 		char *channel_name)
 {
-	int ret = LTTNG_OK, have_event = 0;
+	int ret = LTTNG_OK;
 	struct lttng_ht_iter iter;
 	struct lttng_ht *chan_ht;
 	struct ltt_ust_channel *uchan = NULL;
-	struct ltt_ust_event *uevent = NULL;
 
-	/*
-	 * Define which channel's hashtable to use from the domain or quit if
-	 * unknown domain.
-	 */
-	switch (domain) {
-	case LTTNG_DOMAIN_UST:
-		chan_ht = usess->domain_global.channels;
-		break;
-#if 0
-	case LTTNG_DOMAIN_UST_EXEC_NAME:
-	case LTTNG_DOMAIN_UST_PID:
-	case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
-#endif
-	default:
-		ret = LTTNG_ERR_UND;
-		goto error;
-	}
+	assert(usess);
+	assert(ctx);
+	assert(channel_name);
 
-	/* Do we have an event name */
-	if (strlen(event_name) != 0) {
-		have_event = 1;
-	}
+	rcu_read_lock();
+
+	chan_ht = usess->domain_global.channels;
 
 	/* Get UST channel if defined */
-	if (strlen(channel_name) != 0) {
+	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;
@@ -378,54 +390,28 @@ int context_ust_add(struct ltt_ust_session *usess, int domain,
 		}
 	}
 
-	/* If UST channel specified and event name, get UST event ref */
-	if (uchan && have_event) {
-		uevent = trace_ust_find_event_by_name(uchan->events, event_name);
-		if (uevent == NULL) {
-			ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
-			goto error;
-		}
-	}
-
-	/* At this point, we have 4 possibilities */
-
-	if (uchan && uevent) {				/* Add ctx to event in channel */
-		ret = add_uctx_to_event(usess, domain, uchan, uevent, ctx);
-	} else if (uchan && !have_event) {	/* Add ctx to channel */
+	if (uchan) {
+		/* Add ctx to channel */
 		ret = add_uctx_to_channel(usess, domain, uchan, ctx);
-	} else if (!uchan && have_event) {	/* Add ctx to event */
-		/* Add context to event without having the channel name */
-		cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
-			uevent = trace_ust_find_event_by_name(uchan->events, event_name);
-			if (uevent != NULL) {
-				ret = add_uctx_to_event(usess, domain, uchan, uevent, ctx);
-				/*
-				 * LTTng UST does not allowed the same event to be registered
-				 * multiple time in different or the same channel. So, if we
-				 * found our event, we stop.
-				 */
-				goto end;
-			}
-		}
-		ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
-		goto error;
-	} else if (!uchan && !have_event) {	/* Add ctx all events, all channels */
-		/* For all channels */
+	} 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("Context failed for channel %s", uchan->name);
+			if (ret) {
+				ERR("Failed to add context to channel %s",
+						uchan->name);
 				continue;
 			}
 		}
+		rcu_read_unlock();
 	}
 
-end:
 	switch (ret) {
-	case -EEXIST:
-		ret = LTTNG_ERR_UST_CONTEXT_EXIST;
+	case LTTNG_ERR_UST_CONTEXT_EXIST:
 		break;
 	case -ENOMEM:
+	case -LTTNG_ERR_NOMEM:
 		ret = LTTNG_ERR_FATAL;
 		break;
 	case -EINVAL:
@@ -435,10 +421,15 @@ end:
 		ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 		break;
 	default:
-		ret = LTTNG_OK;
+		if (ret != 0 && ret != LTTNG_OK) {
+			ret = ret > 0 ? ret : LTTNG_ERR_UNK;
+		} else {
+			ret = LTTNG_OK;
+		}
 		break;
 	}
 
 error:
+	rcu_read_unlock();
 	return ret;
 }