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 #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 #endif /* #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG)) */
  72
  73 #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE))
  74
  75 static inline
  76 int wrapper_lttng_fixup_sig(struct module *mod)
  77 {
  78         int ret = 0;
  79
  80         /*
  81          * This is for module.c confusing force loaded modules with
  82          * unsigned modules.
  83          */
  84         if (!THIS_MODULE->sig_ok &&
  85                         THIS_MODULE->taints & (1U << TAINT_FORCED_MODULE)) {
  86                 THIS_MODULE->taints &= ~(1U << TAINT_FORCED_MODULE);
  87                 ret = wrapper_tracepoint_module_notify(NULL,
  88                                 MODULE_STATE_COMING, mod);
  89                 THIS_MODULE->taints |= (1U << TAINT_FORCED_MODULE);
  90         }
  91         return ret;
  92 }
  93
  94 #else /* #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE)) */
  95
  96 static inline
  97 int wrapper_lttng_fixup_sig(struct module *mod)
  98 {
  99         return 0;
 100 }
 101
 102 #endif /* #else #if (LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0) && defined(CONFIG_MODULE_SIG) && defined(MODULE)) */
 103
 104 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0))
 105 static inline struct tracepoint *lttng_tracepoint_ptr_deref(tracepoint_ptr_t *p)
 106 {
 107         return tracepoint_ptr_deref(p);
 108 }
 109 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)) */
 110 static inline struct tracepoint *lttng_tracepoint_ptr_deref(struct tracepoint * const *p)
 111 {
 112         return *p;
 113 }
 114 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)) */
 115
 116 #endif /* _LTTNG_WRAPPER_TRACEPOINT_H */