wrapper/page_alloc.c

   1 /*
   2  * wrapper/page_alloc.c
   3  *
   4  * wrapper around get_pfnblock_flags_mask and Ubuntu
   5  * get_pageblock_flags_mask. Using KALLSYMS to get their address when
   6  * available, else we need to have a kernel that exports this function
   7  * to GPL modules.
   8  *
   9  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * This library is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License as published by the Free Software Foundation; only
  14  * version 2.1 of the License.
  15  *
  16  * This library is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with this library; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  24  */
  25
  26 #include <lttng-kernel-version.h>
  27
  28 #if (defined(CONFIG_KALLSYMS) \
  29         && (LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,2)        \
  30                 || LTTNG_KERNEL_RANGE(3,14,36, 3,15,0)          \
  31                 || LTTNG_KERNEL_RANGE(3,18,10, 3,19,0)          \
  32                 || LTTNG_DEBIAN_KERNEL_RANGE(3,16,7,9,0,0, 3,17,0,0,0,0) \
  33                 || LTTNG_UBUNTU_KERNEL_RANGE(3,16,7,34, 3,17,0,0)))
  34
  35 #include <linux/kallsyms.h>
  36 #include <linux/mm_types.h>
  37 #include <linux/module.h>
  38 #include <wrapper/kallsyms.h>
  39 #include <wrapper/page_alloc.h>
  40
  41 static
  42 unsigned long (*get_pfnblock_flags_mask_sym)(struct page *page,
  43                 unsigned long pfn,
  44                 unsigned long end_bitidx,
  45                 unsigned long mask);
  46
  47 unsigned long wrapper_get_pfnblock_flags_mask(struct page *page,
  48                 unsigned long pfn,
  49                 unsigned long end_bitidx,
  50                 unsigned long mask)
  51 {
  52         WARN_ON_ONCE(!get_pfnblock_flags_mask_sym);
  53         if (get_pfnblock_flags_mask_sym) {
  54                 return get_pfnblock_flags_mask_sym(page, pfn, end_bitidx, mask);
  55         } else {
  56                 return -ENOSYS;
  57         }
  58 }
  59 EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask);
  60
  61 int wrapper_get_pfnblock_flags_mask_init(void)
  62 {
  63         get_pfnblock_flags_mask_sym =
  64                 (void *) kallsyms_lookup_funcptr("get_pfnblock_flags_mask");
  65         if (!get_pfnblock_flags_mask_sym)
  66                 return -1;
  67         return 0;
  68 }
  69
  70 #else
  71
  72 #include <linux/pageblock-flags.h>
  73
  74 #endif
  75
  76 #if (defined(CONFIG_KALLSYMS) \
  77         && LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,50, 3,14,0,0))
  78
  79 #include <linux/kallsyms.h>
  80 #include <linux/mm_types.h>
  81 #include <linux/module.h>
  82 #include <wrapper/kallsyms.h>
  83 #include <wrapper/page_alloc.h>
  84
  85 static
  86 unsigned long (*get_pageblock_flags_mask_sym)(struct page *page,
  87                 unsigned long end_bitidx,
  88                 unsigned long mask);
  89
  90 unsigned long wrapper_get_pageblock_flags_mask(struct page *page,
  91                 unsigned long end_bitidx,
  92                 unsigned long mask)
  93 {
  94         WARN_ON_ONCE(!get_pageblock_flags_mask_sym);
  95         if (get_pageblock_flags_mask_sym) {
  96                 return get_pageblock_flags_mask_sym(page, end_bitidx, mask);
  97         } else {
  98                 return -ENOSYS;
  99         }
 100 }
 101 EXPORT_SYMBOL_GPL(wrapper_get_pageblock_flags_mask);
 102
 103 int wrapper_get_pageblock_flags_mask_init(void)
 104 {
 105         get_pageblock_flags_mask_sym =
 106                 (void *) kallsyms_lookup_funcptr("get_pageblock_flags_mask");
 107         if (!get_pageblock_flags_mask_sym)
 108                 return -1;
 109         return 0;
 110 }
 111
 112 #else
 113
 114 #include <linux/pageblock-flags.h>
 115
 116 #endif