X-Git-Url: http://git.liburcu.org/?p=lttng-modules.git;a=blobdiff_plain;f=lttng-context-ppid.c;h=44956c7e1979c6de39d1d2c2ea93d5c2d454781a;hp=aaa334bc0a3fda482c6404781041955d98af6aad;hb=2459130397d7e7eecc44a5f06a39d65c78257eef;hpb=a90917c3f8c4ed79117f1caa333b29a2108084ec

diff --git a/lttng-context-ppid.c b/lttng-context-ppid.c
index aaa334bc..44956c7e 100644
--- a/lttng-context-ppid.c
+++ b/lttng-context-ppid.c
@@ -1,20 +1,20 @@
-/*
- * (C) Copyright	2009-2011 -
- * 		Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
+ *
+ * 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 "lttng-events.h"
-#include "wrapper/ringbuffer/frontend_types.h"
-#include "wrapper/vmalloc.h"
-#include "lttng-tracer.h"
+#include <lttng-events.h>
+#include <ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <lttng-tracer.h>
 
 static
 size_t ppid_get_size(size_t offset)
@@ -33,6 +33,13 @@ void ppid_record(struct lttng_ctx_field *field,
 {
 	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();
@@ -40,6 +47,26 @@ void ppid_record(struct lttng_ctx_field *field,
 	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;
@@ -53,19 +80,17 @@ 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 = lttng_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.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->event_field.type.u.integer.size = sizeof(pid_t) * CHAR_BIT;
+	field->event_field.type.u.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
+	field->event_field.type.u.integer.signedness = lttng_is_signed_type(pid_t);
+	field->event_field.type.u.integer.reverse_byte_order = 0;
+	field->event_field.type.u.integer.base = 10;
+	field->event_field.type.u.integer.encoding = lttng_encode_none;
 	field->get_size = ppid_get_size;
 	field->record = ppid_record;
-	wrapper_vmalloc_sync_all();
+	field->get_value = ppid_get_value;
+	lttng_context_update(*ctx);
+	wrapper_vmalloc_sync_mappings();
 	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");