wrapper/tracepoint.h

   1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
   2  *
   3  * wrapper/tracepoint.h
   4  *
   5  * wrapper around DECLARE_EVENT_CLASS.
   6  *
   7  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  */
   9
  10 #ifndef _LTTNG_WRAPPER_TRACEPOINT_H
  11 #define _LTTNG_WRAPPER_TRACEPOINT_H
  12
  13 #include <linux/version.h>
  14 #include <linux/tracepoint.h>
  15 #include <linux/module.h>
  16
  17 #ifndef HAVE_KABI_2635_TRACEPOINT
  18
  19 #define kabi_2635_tracepoint_probe_register tracepoint_probe_register
  20 #define kabi_2635_tracepoint_probe_unregister tracepoint_probe_unregister
  21
  22 #endif /* HAVE_KABI_2635_TRACEPOINT */
  23
  24 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0))
  25
  26 #include <lttng-tracepoint.h>
  27
  28 #define lttng_wrapper_tracepoint_probe_register lttng_tracepoint_probe_register
  29 #define lttng_wrapper_tracepoint_probe_unregister lttng_tracepoint_probe_unregister
  30
  31 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)) */
  32
  33 #define lttng_wrapper_tracepoint_probe_register kabi_2635_tracepoint_probe_register
  34 #define lttng_wrapper_tracepoint_probe_unregister kabi_2635_tracepoint_probe_unregister
  35
  36 static inline
  37 int lttng_tracepoint_init(void)
  38 {
  39         return 0;
  40 }
  41
  42 static inline
  43 void lttng_tracepoint_exit(void)
  44 {
  45 }
  46
  47 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)) */
  48
  49 #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG))
  50
  51 #include <linux/kallsyms.h>
  52 #include <wrapper/kallsyms.h>
  53
  54 static inline
  55 int wrapper_tracepoint_module_notify(struct notifier_block *nb,
  56                 unsigned long val, struct module *mod)
  57 {
  58         int (*tracepoint_module_notify_sym)(struct notifier_block *nb,
  59                         unsigned long val, struct module *mod);
  60
  61         tracepoint_module_notify_sym =
  62                 (void *) kallsyms_lookup_funcptr("tracepoint_module_notify");
  63         if (tracepoint_module_notify_sym) {
  64                 return tracepoint_module_notify_sym(nb, val, mod);
  65         } else {
  66                 printk_once(KERN_WARNING "LTTng: tracepoint_module_notify symbol lookup failed. It probably means you kernel don't need this work-around. Please consider upgrading LTTng modules to make this warning go away.\n");
  67                 return -ENOSYS;
  68         }
  69 }
  70
  71 /*
  72  * No canary for 'tracepoint_module_notify()', it's only defined in 'kernel/tracepoint.c'.
  73  *
  74  * static inline
  75  * int __canary__tracepoint_module_notify(struct notifier_block *nb,
  76  *              unsigned long val, struct module *mod)
  77  * {
  78  *      return tracepoint_module_notify(nb, val, mod);
  79  * }
  80  */
  81
  82 #endif /* #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG)) */
  83
  84 #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE))
  85
  86 static inline
  87 int wrapper_lttng_fixup_sig(struct module *mod)
  88 {
  89         int ret = 0;
  90
  91         /*
  92          * This is for module.c confusing force loaded modules with
  93          * unsigned modules.
  94          */
  95         if (!THIS_MODULE->sig_ok &&
  96                         THIS_MODULE->taints & (1U << TAINT_FORCED_MODULE)) {
  97                 THIS_MODULE->taints &= ~(1U << TAINT_FORCED_MODULE);
  98                 ret = wrapper_tracepoint_module_notify(NULL,
  99                                 MODULE_STATE_COMING, mod);
 100                 THIS_MODULE->taints |= (1U << TAINT_FORCED_MODULE);
 101         }
 102         return ret;
 103 }
 104
 105 #else /* #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE)) */
 106
 107 static inline
 108 int wrapper_lttng_fixup_sig(struct module *mod)
 109 {
 110         return 0;
 111 }
 112
 113 #endif /* #else #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE)) */
 114
 115 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0))
 116 static inline struct tracepoint *lttng_tracepoint_ptr_deref(tracepoint_ptr_t *p)
 117 {
 118         return tracepoint_ptr_deref(p);
 119 }
 120 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)) */
 121 static inline struct tracepoint *lttng_tracepoint_ptr_deref(struct tracepoint * const *p)
 122 {
 123         return *p;
 124 }
 125 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)) */
 126
 127 #endif /* _LTTNG_WRAPPER_TRACEPOINT_H */