Drop support for kernels < 3.0 from skb instrumentation

[lttng-modules.git] / lttng-context-ppid.c

diff --git a/lttng-context-ppid.c b/lttng-context-ppid.c
index 58ff3fe719200bf9c8bf964feb47eb72e5f65c4d..ef84ad1109e52967c94d7e272db510765c92492c 100644 (file)
--- a/lttng-context-ppid.c
+++ b/lttng-context-ppid.c
@@ -1,33 +1,20 @@
-/*
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
  * lttng-context-ppid.c
  *
  * LTTng PPID context.
  *
  * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library 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
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #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 <wrapper/ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <lttng-tracer.h>
 
 static
 size_t ppid_get_size(size_t offset)
@@ -46,7 +33,6 @@ 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
@@ -54,7 +40,6 @@ void ppid_record(struct lttng_ctx_field *field,
         * 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();
@@ -62,6 +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;
@@ -77,17 +82,15 @@ int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx)
        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.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");