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 <lttng/kernel-version.h>
  14 #include <linux/tracepoint.h>
  15 #include <linux/module.h>
  16
  17 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_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 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,15,0))
  26
  27 #include <lttng/tracepoint.h>
  28
  29 #define lttng_wrapper_tracepoint_probe_register lttng_tracepoint_probe_register
  30 #define lttng_wrapper_tracepoint_probe_unregister lttng_tracepoint_probe_unregister
  31
  32 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,15,0)) */
  33
  34 #define lttng_wrapper_tracepoint_probe_register tracepoint_probe_register
  35 #define lttng_wrapper_tracepoint_probe_unregister tracepoint_probe_unregister
  36
  37 static inline
  38 int lttng_tracepoint_init(void)
  39 {
  40         return 0;
  41 }
  42
  43 static inline
  44 void lttng_tracepoint_exit(void)
  45 {
  46 }
  47
  48 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,15,0)) */
  49
  50 #if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG))
  51
  52 #include <linux/kallsyms.h>
  53 #include <wrapper/kallsyms.h>
  54
  55 static inline
  56 int wrapper_tracepoint_module_notify(struct notifier_block *nb,
  57                 unsigned long val, struct module *mod)
  58 {
  59         int (*tracepoint_module_notify_sym)(struct notifier_block *nb,
  60                         unsigned long val, struct module *mod);
  61
  62         tracepoint_module_notify_sym =
  63                 (void *) kallsyms_lookup_funcptr("tracepoint_module_notify");
  64         if (tracepoint_module_notify_sym) {
  65                 return tracepoint_module_notify_sym(nb, val, mod);
  66         } else {
  67                 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");
  68                 return -ENOSYS;
  69         }
  70 }
  71
  72 /*
  73  * No canary for 'tracepoint_module_notify()', it's only defined in 'kernel/tracepoint.c'.
  74  *
  75  * static inline
  76  * int __canary__tracepoint_module_notify(struct notifier_block *nb,
  77  *              unsigned long val, struct module *mod)
  78  * {
  79  *      return tracepoint_module_notify(nb, val, mod);
  80  * }
  81  */
  82
  83 #endif /* #if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG)) */
  84
  85 #if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE))
  86
  87 static inline
  88 int wrapper_lttng_fixup_sig(struct module *mod)
  89 {
  90         int ret = 0;
  91
  92         /*
  93          * This is for module.c confusing force loaded modules with
  94          * unsigned modules.
  95          */
  96         if (!THIS_MODULE->sig_ok &&
  97                         THIS_MODULE->taints & (1U << TAINT_FORCED_MODULE)) {
  98                 THIS_MODULE->taints &= ~(1U << TAINT_FORCED_MODULE);
  99                 ret = wrapper_tracepoint_module_notify(NULL,
 100                                 MODULE_STATE_COMING, mod);
 101                 THIS_MODULE->taints |= (1U << TAINT_FORCED_MODULE);
 102         }
 103         return ret;
 104 }
 105
 106 #else /* #if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE)) */
 107
 108 static inline
 109 int wrapper_lttng_fixup_sig(struct module *mod)
 110 {
 111         return 0;
 112 }
 113
 114 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE)) */
 115
 116 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,19,0))
 117 static inline struct tracepoint *lttng_tracepoint_ptr_deref(tracepoint_ptr_t *p)
 118 {
 119         return tracepoint_ptr_deref(p);
 120 }
 121 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,19,0)) */
 122 static inline struct tracepoint *lttng_tracepoint_ptr_deref(struct tracepoint * const *p)
 123 {
 124         return *p;
 125 }
 126 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,19,0)) */
 127
 128 #endif /* _LTTNG_WRAPPER_TRACEPOINT_H */