X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lttng-context-hostname.c;h=791fed4618f48a025ef1c543087dcb4cd5d1ac3e;hb=7299e758b109db074589f7879ae631b27c25dc05;hp=e38340b72ec7bf53f8272ddacac5cf7434212498;hpb=975da2c003441a8a16a36947e9500237c197e91b;p=lttng-modules.git

diff --git a/lttng-context-hostname.c b/lttng-context-hostname.c
index e38340b7..791fed46 100644
--- a/lttng-context-hostname.c
+++ b/lttng-context-hostname.c
@@ -24,10 +24,10 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/utsname.h>
-#include "lttng-events.h"
-#include "wrapper/ringbuffer/frontend_types.h"
-#include "wrapper/vmalloc.h"
-#include "lttng-tracer.h"
+#include <lttng-events.h>
+#include <wrapper/ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <lttng-tracer.h>
 
 #define LTTNG_HOSTNAME_CTX_LEN	(__NEW_UTS_LEN + 1)
 
@@ -49,8 +49,11 @@ void hostname_record(struct lttng_ctx_field *field,
 	struct uts_namespace *ns;
 	char *hostname;
 
-	rcu_read_lock();
-	nsproxy = task_nsproxy(current);
+	/*
+	 * No need to take the RCU read-side lock to read current
+	 * nsproxy. (documented in nsproxy.h)
+	 */
+	nsproxy = current->nsproxy;
 	if (nsproxy) {
 		ns = nsproxy->uts_ns;
 		hostname = ns->name.nodename;
@@ -60,7 +63,29 @@ void hostname_record(struct lttng_ctx_field *field,
 		chan->ops->event_memset(ctx, 0,
 				LTTNG_HOSTNAME_CTX_LEN);
 	}
-	rcu_read_unlock();
+}
+
+static
+void hostname_get_value(struct lttng_ctx_field *field,
+		struct lttng_probe_ctx *lttng_probe_ctx,
+		union lttng_ctx_value *value)
+{
+	struct nsproxy *nsproxy;
+	struct uts_namespace *ns;
+	char *hostname;
+
+	/*
+	 * No need to take the RCU read-side lock to read current
+	 * nsproxy. (documented in nsproxy.h)
+	 */
+	nsproxy = current->nsproxy;
+	if (nsproxy) {
+		ns = nsproxy->uts_ns;
+		hostname = ns->name.nodename;
+	} else {
+		hostname = "";
+	}
+	value->str = hostname;
 }
 
 int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx)
@@ -79,7 +104,7 @@ int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx)
 	field->event_field.type.u.array.elem_type.atype = atype_integer;
 	field->event_field.type.u.array.elem_type.u.basic.integer.size = sizeof(char) * CHAR_BIT;
 	field->event_field.type.u.array.elem_type.u.basic.integer.alignment = lttng_alignof(char) * CHAR_BIT;
-	field->event_field.type.u.array.elem_type.u.basic.integer.signedness = is_signed_type(char);
+	field->event_field.type.u.array.elem_type.u.basic.integer.signedness = lttng_is_signed_type(char);
 	field->event_field.type.u.array.elem_type.u.basic.integer.reverse_byte_order = 0;
 	field->event_field.type.u.array.elem_type.u.basic.integer.base = 10;
 	field->event_field.type.u.array.elem_type.u.basic.integer.encoding = lttng_encode_UTF8;
@@ -87,11 +112,9 @@ int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx)
 
 	field->get_size = hostname_get_size;
 	field->record = hostname_record;
+	field->get_value = hostname_get_value;
+	lttng_context_update(*ctx);
 	wrapper_vmalloc_sync_all();
 	return 0;
 }
 EXPORT_SYMBOL_GPL(lttng_add_hostname_to_ctx);
-
-MODULE_LICENSE("GPL and additional rights");
-MODULE_AUTHOR("Mathieu Desnoyers");
-MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support");