X-Git-Url: http://git.liburcu.org/?p=lttng-modules.git;a=blobdiff_plain;f=lttng-context-ppid.c;h=ef84ad1109e52967c94d7e272db510765c92492c;hp=738f7e6882d518d95b2ebe559ede4e683363bbf9;hb=27e6eda75df97483d07d61ba731bbc428e2161f9;hpb=44252f0fd51fd4bf28926dcef525355bceb08c5f

diff --git a/lttng-context-ppid.c b/lttng-context-ppid.c
index 738f7e68..ef84ad11 100644
--- a/lttng-context-ppid.c
+++ b/lttng-context-ppid.c
@@ -1,27 +1,27 @@
-/*
- * (C) Copyright	2009-2011 -
- * 		Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
+ * lttng-context-ppid.c
  *
  * LTTng PPID context.
  *
- * Dual LGPL v2.1/GPL v2 license.
+ * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  */
 
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/syscalls.h>
-#include "ltt-events.h"
-#include "wrapper/ringbuffer/frontend_types.h"
-#include "wrapper/vmalloc.h"
-#include "ltt-tracer.h"
+#include <lttng-events.h>
+#include <wrapper/ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <lttng-tracer.h>
 
 static
 size_t ppid_get_size(size_t offset)
 {
 	size_t size = 0;
 
-	size += lib_ring_buffer_align(offset, ltt_alignof(pid_t));
+	size += lib_ring_buffer_align(offset, lttng_alignof(pid_t));
 	size += sizeof(pid_t);
 	return size;
 }
@@ -29,17 +29,44 @@ size_t ppid_get_size(size_t offset)
 static
 void ppid_record(struct lttng_ctx_field *field,
 		 struct lib_ring_buffer_ctx *ctx,
-		 struct ltt_channel *chan)
+		 struct lttng_channel *chan)
 {
 	pid_t ppid;
 
+	/*
+	 * TODO: when we eventually add RCU subsystem instrumentation,
+	 * taking the rcu read lock here will trigger RCU tracing
+	 * recursively. We should modify the kernel synchronization so
+	 * it synchronizes both for RCU and RCU sched, and rely on
+	 * rcu_read_lock_sched_notrace.
+	 */
 	rcu_read_lock();
 	ppid = task_tgid_nr(current->real_parent);
 	rcu_read_unlock();
-	lib_ring_buffer_align_ctx(ctx, ltt_alignof(ppid));
+	lib_ring_buffer_align_ctx(ctx, lttng_alignof(ppid));
 	chan->ops->event_write(ctx, &ppid, sizeof(ppid));
 }
 
+static
+void ppid_get_value(struct lttng_ctx_field *field,
+		struct lttng_probe_ctx *lttng_probe_ctx,
+		union lttng_ctx_value *value)
+{
+	pid_t ppid;
+
+	/*
+	 * TODO: when we eventually add RCU subsystem instrumentation,
+	 * taking the rcu read lock here will trigger RCU tracing
+	 * recursively. We should modify the kernel synchronization so
+	 * it synchronizes both for RCU and RCU sched, and rely on
+	 * rcu_read_lock_sched_notrace.
+	 */
+	rcu_read_lock();
+	ppid = task_tgid_nr(current->real_parent);
+	rcu_read_unlock();
+	value->s64 = ppid;
+}
+
 int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx)
 {
 	struct lttng_ctx_field *field;
@@ -54,18 +81,16 @@ int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx)
 	field->event_field.name = "ppid";
 	field->event_field.type.atype = atype_integer;
 	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
-	field->event_field.type.u.basic.integer.alignment = ltt_alignof(pid_t) * CHAR_BIT;
-	field->event_field.type.u.basic.integer.signedness = is_signed_type(pid_t);
+	field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
+	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
 	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
 	field->event_field.type.u.basic.integer.base = 10;
 	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
 	field->get_size = ppid_get_size;
 	field->record = ppid_record;
+	field->get_value = ppid_get_value;
+	lttng_context_update(*ctx);
 	wrapper_vmalloc_sync_all();
 	return 0;
 }
 EXPORT_SYMBOL_GPL(lttng_add_ppid_to_ctx);
-
-MODULE_LICENSE("GPL and additional rights");
-MODULE_AUTHOR("Mathieu Desnoyers");
-MODULE_DESCRIPTION("Linux Trace Toolkit PPID Context");