Remove dependency on kallsyms for splice_to_pipe (kernel 4.2+)

[lttng-modules.git] / probes / lttng-ftrace.c

diff --git a/probes/lttng-ftrace.c b/probes/lttng-ftrace.c
index bc4bd5baae6f90d7bf22eceb3e7cfa5e57ef07de..fe1bfd6652ab837a0911b566b3c5dc6759d28043 100644 (file)
--- a/probes/lttng-ftrace.c
+++ b/probes/lttng-ftrace.c
@@ -1,23 +1,10 @@
-/*
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
  * probes/lttng-ftrace.c
  *
  * LTTng function tracer integration module.
  *
  * 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
  */
 
 /*
@@ -33,16 +20,59 @@
 #include <linux/module.h>
 #include <linux/ftrace.h>
 #include <linux/slab.h>
-#include "../lttng-events.h"
-#include "../wrapper/ringbuffer/frontend_types.h"
-#include "../wrapper/ftrace.h"
-#include "../wrapper/vmalloc.h"
-#include "../lttng-tracer.h"
+#include <lttng-events.h>
+#include <wrapper/ringbuffer/frontend_types.h>
+#include <wrapper/ftrace.h>
+#include <wrapper/vmalloc.h>
+#include <lttng-tracer.h>
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
+static
+void lttng_ftrace_handler(unsigned long ip, unsigned long parent_ip,
+               struct trace_array *tr, struct ftrace_probe_ops *ops,
+               void *data)
+{
+       struct lttng_event *event = data;
+       struct lttng_probe_ctx lttng_probe_ctx = {
+               .event = event,
+               .interruptible = !irqs_disabled(),
+       };
+       struct lttng_channel *chan = event->chan;
+       struct lib_ring_buffer_ctx ctx;
+       struct {
+               unsigned long ip;
+               unsigned long parent_ip;
+       } payload;
+       int ret;
 
+       if (unlikely(!READ_ONCE(chan->session->active)))
+               return;
+       if (unlikely(!READ_ONCE(chan->enabled)))
+               return;
+       if (unlikely(!READ_ONCE(event->enabled)))
+               return;
+
+       lib_ring_buffer_ctx_init(&ctx, chan->chan, &lttng_probe_ctx,
+                                sizeof(payload), lttng_alignof(payload), -1);
+       ret = chan->ops->event_reserve(&ctx, event->id);
+       if (ret < 0)
+               return;
+       payload.ip = ip;
+       payload.parent_ip = parent_ip;
+       lib_ring_buffer_align_ctx(&ctx, lttng_alignof(payload));
+       chan->ops->event_write(&ctx, &payload, sizeof(payload));
+       chan->ops->event_commit(&ctx);
+       return;
+}
+#else
 static
 void lttng_ftrace_handler(unsigned long ip, unsigned long parent_ip, void **data)
 {
        struct lttng_event *event = *data;
+       struct lttng_probe_ctx lttng_probe_ctx = {
+               .event = event,
+               .interruptible = !irqs_disabled(),
+       };
        struct lttng_channel *chan = event->chan;
        struct lib_ring_buffer_ctx ctx;
        struct {
@@ -51,14 +81,14 @@ void lttng_ftrace_handler(unsigned long ip, unsigned long parent_ip, void **data
        } payload;
        int ret;
 
-       if (unlikely(!ACCESS_ONCE(chan->session->active)))
+       if (unlikely(!READ_ONCE(chan->session->active)))
                return;
-       if (unlikely(!ACCESS_ONCE(chan->enabled)))
+       if (unlikely(!READ_ONCE(chan->enabled)))
                return;
-       if (unlikely(!ACCESS_ONCE(event->enabled)))
+       if (unlikely(!READ_ONCE(event->enabled)))
                return;
 
-       lib_ring_buffer_ctx_init(&ctx, chan->chan, event,
+       lib_ring_buffer_ctx_init(&ctx, chan->chan, &lttng_probe_ctx,
                                 sizeof(payload), lttng_alignof(payload), -1);
        ret = chan->ops->event_reserve(&ctx, event->id);
        if (ret < 0)
@@ -70,6 +100,7 @@ void lttng_ftrace_handler(unsigned long ip, unsigned long parent_ip, void **data
        chan->ops->event_commit(&ctx);
        return;
 }
+#endif
 
 /*
  * Create event description
@@ -197,8 +228,8 @@ void lttng_ftrace_exit(void)
 module_exit(lttng_ftrace_exit)
 
 MODULE_LICENSE("GPL and additional rights");
-MODULE_AUTHOR("Mathieu Desnoyers");
-MODULE_DESCRIPTION("Linux Trace Toolkit Ftrace Support");
+MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>");
+MODULE_DESCRIPTION("LTTng ftrace probes");
 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
        __stringify(LTTNG_MODULES_MINOR_VERSION) "."
        __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)