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 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,35))
  18
  19 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
  20
  21 #endif
  22
  23 #ifndef HAVE_KABI_2635_TRACEPOINT
  24
  25 #define kabi_2635_tracepoint_probe_register tracepoint_probe_register
  26 #define kabi_2635_tracepoint_probe_unregister tracepoint_probe_unregister
  27
  28 #endif /* HAVE_KABI_2635_TRACEPOINT */
  29
  30 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0))
  31
  32 #include <lttng-tracepoint.h>
  33
  34 #define lttng_wrapper_tracepoint_probe_register lttng_tracepoint_probe_register
  35 #define lttng_wrapper_tracepoint_probe_unregister lttng_tracepoint_probe_unregister
  36
  37 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)) */
  38
  39 #define lttng_wrapper_tracepoint_probe_register kabi_2635_tracepoint_probe_register
  40 #define lttng_wrapper_tracepoint_probe_unregister kabi_2635_tracepoint_probe_unregister
  41
  42 static inline
  43 int lttng_tracepoint_init(void)
  44 {
  45         return 0;
  46 }
  47
  48 static inline
  49 void lttng_tracepoint_exit(void)
  50 {
  51 }
  52
  53 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)) */
  54
  55 #ifdef CONFIG_MODULE_SIG
  56
  57 #include <linux/kallsyms.h>
  58 #include <wrapper/kallsyms.h>
  59
  60 static inline
  61 int wrapper_tracepoint_module_notify(struct notifier_block *nb,
  62                 unsigned long val, struct module *mod)
  63 {
  64         int (*tracepoint_module_notify_sym)(struct notifier_block *nb,
  65                         unsigned long val, struct module *mod);
  66
  67         tracepoint_module_notify_sym =
  68                 (void *) kallsyms_lookup_funcptr("tracepoint_module_notify");
  69         if (tracepoint_module_notify_sym) {
  70                 return tracepoint_module_notify_sym(nb, val, mod);
  71         } else {
  72                 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");
  73                 return -ENOSYS;
  74         }
  75 }
  76
  77 #endif /* CONFIG_MODULE_SIG */
  78
  79 #if defined(CONFIG_MODULE_SIG) && defined(MODULE)
  80
  81 static inline
  82 int wrapper_lttng_fixup_sig(struct module *mod)
  83 {
  84         int ret = 0;
  85
  86         /*
  87          * This is for module.c confusing force loaded modules with
  88          * unsigned modules.
  89          */
  90         if (!THIS_MODULE->sig_ok &&
  91                         THIS_MODULE->taints & (1U << TAINT_FORCED_MODULE)) {
  92                 THIS_MODULE->taints &= ~(1U << TAINT_FORCED_MODULE);
  93                 ret = wrapper_tracepoint_module_notify(NULL,
  94                                 MODULE_STATE_COMING, mod);
  95                 THIS_MODULE->taints |= (1U << TAINT_FORCED_MODULE);
  96         }
  97         return ret;
  98 }
  99
 100 #else /* #if defined(CONFIG_MODULE_SIG) && defined(MODULE) */
 101
 102 static inline
 103 int wrapper_lttng_fixup_sig(struct module *mod)
 104 {
 105         return 0;
 106 }
 107
 108 #endif /*#else #if defined(CONFIG_MODULE_SIG) && defined(MODULE) */
 109
 110 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0))
 111 static inline struct tracepoint *lttng_tracepoint_ptr_deref(tracepoint_ptr_t *p)
 112 {
 113         return tracepoint_ptr_deref(p);
 114 }
 115 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)) */
 116 static inline struct tracepoint *lttng_tracepoint_ptr_deref(struct tracepoint * const *p)
 117 {
 118         return *p;
 119 }
 120 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,19,0)) */
 121
 122 #endif /* _LTTNG_WRAPPER_TRACEPOINT_H */