wrapper/page_alloc.c

   1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
   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
  12 #include <lttng-kernel-version.h>
  13
  14 #if (defined(CONFIG_KALLSYMS) \
  15         && (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,19,2)    \
  16                 || LTTNG_KERNEL_RANGE(3,14,36, 3,15,0)          \
  17                 || LTTNG_KERNEL_RANGE(3,18,10, 3,19,0)          \
  18                 || LTTNG_DEBIAN_KERNEL_RANGE(3,16,7,9,0,0, 3,17,0,0,0,0) \
  19                 || LTTNG_UBUNTU_KERNEL_RANGE(3,16,7,34, 3,17,0,0)))
  20
  21 /* Include page_alloc wrapper before pageblock-flags.h. */
  22 #include <wrapper/page_alloc.h>
  23
  24 #include <linux/pageblock-flags.h>
  25 #include <linux/kallsyms.h>
  26 #include <linux/mm_types.h>
  27 #include <linux/module.h>
  28 #include <wrapper/kallsyms.h>
  29 #include <lttng-kernel-version.h>
  30
  31 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,14,0))
  32 static
  33 unsigned long (*get_pfnblock_flags_mask_sym)(const struct page *page,
  34                 unsigned long pfn,
  35                 unsigned long mask);
  36
  37 unsigned long wrapper_get_pfnblock_flags_mask(const struct page *page,
  38                 unsigned long pfn,
  39                 unsigned long mask)
  40 {
  41         WARN_ON_ONCE(!get_pfnblock_flags_mask_sym);
  42         if (get_pfnblock_flags_mask_sym) {
  43                 return get_pfnblock_flags_mask_sym(page, pfn, mask);
  44         } else {
  45                 return -ENOSYS;
  46         }
  47 }
  48 #elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,9,0))
  49 static
  50 unsigned long (*get_pfnblock_flags_mask_sym)(struct page *page,
  51                 unsigned long pfn,
  52                 unsigned long mask);
  53
  54 unsigned long wrapper_get_pfnblock_flags_mask(struct page *page,
  55                 unsigned long pfn,
  56                 unsigned long mask)
  57 {
  58         WARN_ON_ONCE(!get_pfnblock_flags_mask_sym);
  59         if (get_pfnblock_flags_mask_sym) {
  60                 return get_pfnblock_flags_mask_sym(page, pfn, mask);
  61         } else {
  62                 return -ENOSYS;
  63         }
  64 }
  65 #else   /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,9,0)) */
  66 static
  67 unsigned long (*get_pfnblock_flags_mask_sym)(struct page *page,
  68                 unsigned long pfn,
  69                 unsigned long end_bitidx,
  70                 unsigned long mask);
  71
  72 unsigned long wrapper_get_pfnblock_flags_mask(struct page *page,
  73                 unsigned long pfn,
  74                 unsigned long end_bitidx,
  75                 unsigned long mask)
  76 {
  77         WARN_ON_ONCE(!get_pfnblock_flags_mask_sym);
  78         if (get_pfnblock_flags_mask_sym) {
  79                 return get_pfnblock_flags_mask_sym(page, pfn, end_bitidx, mask);
  80         } else {
  81                 return -ENOSYS;
  82         }
  83 }
  84 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,9,0)) */
  85
  86 EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask);
  87
  88 int wrapper_get_pfnblock_flags_mask_init(void)
  89 {
  90         get_pfnblock_flags_mask_sym =
  91                 (void *) kallsyms_lookup_funcptr("get_pfnblock_flags_mask");
  92         if (!get_pfnblock_flags_mask_sym)
  93                 return -1;
  94         return 0;
  95 }
  96 EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);
  97
  98 #else
  99
 100 #include <linux/pageblock-flags.h>
 101
 102 #endif
 103
 104 #if (defined(CONFIG_KALLSYMS) \
 105         && LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,50, 3,14,0,0))
 106
 107 #include <linux/kallsyms.h>
 108 #include <linux/mm_types.h>
 109 #include <linux/module.h>
 110 #include <wrapper/kallsyms.h>
 111 #include <wrapper/page_alloc.h>
 112
 113 static
 114 unsigned long (*get_pageblock_flags_mask_sym)(struct page *page,
 115                 unsigned long end_bitidx,
 116                 unsigned long mask);
 117
 118 unsigned long wrapper_get_pageblock_flags_mask(struct page *page,
 119                 unsigned long end_bitidx,
 120                 unsigned long mask)
 121 {
 122         WARN_ON_ONCE(!get_pageblock_flags_mask_sym);
 123         if (get_pageblock_flags_mask_sym) {
 124                 return get_pageblock_flags_mask_sym(page, end_bitidx, mask);
 125         } else {
 126                 return -ENOSYS;
 127         }
 128 }
 129 EXPORT_SYMBOL_GPL(wrapper_get_pageblock_flags_mask);
 130
 131 int wrapper_get_pageblock_flags_mask_init(void)
 132 {
 133         get_pageblock_flags_mask_sym =
 134                 (void *) kallsyms_lookup_funcptr("get_pageblock_flags_mask");
 135         if (!get_pageblock_flags_mask_sym)
 136                 return -1;
 137         return 0;
 138 }
 139 EXPORT_SYMBOL_GPL(wrapper_get_pfnblock_flags_mask_init);
 140
 141 #else
 142
 143 #include <linux/pageblock-flags.h>
 144
 145 #endif