Detect missing symbols used with kallsyms_lookup at compile time

[lttng-modules.git] / wrapper / page_alloc.c

diff --git a/wrapper/page_alloc.c b/wrapper/page_alloc.c
index dc1fbed225fd6aefce00661aa1c7581793246e0f..2de24f9e07edc62daf1caae51824464f31eeb5ff 100644 (file)
--- a/wrapper/page_alloc.c
+++ b/wrapper/page_alloc.c
@@ -1,4 +1,4 @@
-/*
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
  * wrapper/page_alloc.c
  *
  * wrapper around get_pfnblock_flags_mask and Ubuntu
@@ -7,20 +7,6 @@
  * to GPL modules.
  *
  * Copyright (C) 2015 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 <lttng-kernel-version.h>
@@ -66,6 +52,26 @@ int wrapper_get_pfnblock_flags_mask_init(void)
                return -1;
        return 0;
 }
+EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);
+
+/*
+ * Canary function to check for 'get_pfnblock_flags_mask()' at compile time.
+ *
+ * From 'include/linux/pageblock-flags.h':
+ *
+ *   unsigned long get_pfnblock_flags_mask(struct page *page,
+ *                                         unsigned long pfn,
+ *                                         unsigned long end_bitidx,
+ *                                         unsigned long mask);
+ */
+__attribute__((unused)) static
+unsigned long __canary__get_pfnblock_flags_mask(struct page *page,
+                                               unsigned long pfn,
+                                               unsigned long end_bitidx,
+                                               unsigned long mask)
+{
+       return get_pfnblock_flags_mask(page, pfn, end_bitidx, mask);
+}
 
 #else
 
@@ -108,6 +114,7 @@ int wrapper_get_pageblock_flags_mask_init(void)
                return -1;
        return 0;
 }
+EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);
 
 #else