include/wrapper/tracepoint.h

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   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 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,10,0))
  18 #define LTTNG_DEFINE_TRACE(name, proto, args)           \
  19         DEFINE_TRACE(name, PARAMS(proto), PARAMS(args))
  20 #else
  21 #define LTTNG_DEFINE_TRACE(name, proto, args)           \
  22         DEFINE_TRACE(name)
  23 #endif
  24
  25 #ifndef HAVE_KABI_2635_TRACEPOINT
  26
  27 #define kabi_2635_tracepoint_probe_register tracepoint_probe_register
  28 #define kabi_2635_tracepoint_probe_unregister tracepoint_probe_unregister
  29
  30 #endif /* HAVE_KABI_2635_TRACEPOINT */
  31
  32 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0))
  33
  34 #include <lttng/tracepoint.h>
  35
  36 #define lttng_wrapper_tracepoint_probe_register lttng_tracepoint_probe_register
  37 #define lttng_wrapper_tracepoint_probe_unregister lttng_tracepoint_probe_unregister
  38
  39 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)) */
  40
  41 #define lttng_wrapper_tracepoint_probe_register kabi_2635_tracepoint_probe_register
  42 #define lttng_wrapper_tracepoint_probe_unregister kabi_2635_tracepoint_probe_unregister
  43
  44 static inline
  45 int lttng_tracepoint_init(void)
  46 {
  47         return 0;
  48 }
  49
  50 static inline
  51 void lttng_tracepoint_exit(void)
  52 {
  53 }
  54
  55 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)) */
  56
  57 #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG))
  58
  59 #include <linux/kallsyms.h>
  60 #include <wrapper/kallsyms.h>
  61
  62 static inline
  63 int wrapper_tracepoint_module_notify(struct notifier_block *nb,
  64                 unsigned long val, struct module *mod)
  65 {
  66         int (*tracepoint_module_notify_sym)(struct notifier_block *nb,
  67                         unsigned long val, struct module *mod);
  68
  69         tracepoint_module_notify_sym =
  70                 (void *) kallsyms_lookup_funcptr("tracepoint_module_notify");
  71         if (tracepoint_module_notify_sym) {
  72                 return tracepoint_module_notify_sym(nb, val, mod);
  73         } else {
  74                 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");
  75                 return -ENOSYS;
  76         }
  77 }
  78
  79 /*
  80  * No canary for 'tracepoint_module_notify()', it's only defined in 'kernel/tracepoint.c'.
  81  *
  82  * static inline
  83  * int __canary__tracepoint_module_notify(struct notifier_block *nb,
  84  *              unsigned long val, struct module *mod)
  85  * {
  86  *      return tracepoint_module_notify(nb, val, mod);
  87  * }
  88  */
  89
  90 #endif /* #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG)) */
  91
  92 #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE))
  93
  94 static inline
  95 int wrapper_lttng_fixup_sig(struct module *mod)
  96 {
  97         int ret = 0;
  98
  99         /*
 100          * This is for module.c confusing force loaded modules with
 101          * unsigned modules.
 102          */
 103         if (!THIS_MODULE->sig_ok &&
 104                         THIS_MODULE->taints & (1U << TAINT_FORCED_MODULE)) {
 105                 THIS_MODULE->taints &= ~(1U << TAINT_FORCED_MODULE);
 106                 ret = wrapper_tracepoint_module_notify(NULL,
 107                                 MODULE_STATE_COMING, mod);
 108                 THIS_MODULE->taints |= (1U << TAINT_FORCED_MODULE);
 109         }
 110         return ret;
 111 }
 112
 113 #else /* #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE)) */
 114
 115 static inline
 116 int wrapper_lttng_fixup_sig(struct module *mod)
 117 {
 118         return 0;
 119 }
 120
 121 #endif /* #else #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE)) */
 122
 123 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0))
 124 static inline struct tracepoint *lttng_tracepoint_ptr_deref(tracepoint_ptr_t *p)
 125 {
 126         return tracepoint_ptr_deref(p);
 127 }
 128 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)) */
 129 static inline struct tracepoint *lttng_tracepoint_ptr_deref(struct tracepoint * const *p)
 130 {
 131         return *p;
 132 }
 133 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)) */
 134
 135 #endif /* _LTTNG_WRAPPER_TRACEPOINT_H */