wrapper/tracepoint.h

   1 #ifndef _LTTNG_WRAPPER_TRACEPOINT_H
   2 #define _LTTNG_WRAPPER_TRACEPOINT_H
   3
   4 /*
   5  * wrapper/tracepoint.h
   6  *
   7  * wrapper around DECLARE_EVENT_CLASS.
   8  *
   9  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * This library is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License as published by the Free Software Foundation; only
  14  * version 2.1 of the License.
  15  *
  16  * This library is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with this library; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  24  */
  25
  26 #include <linux/version.h>
  27 #include <linux/tracepoint.h>
  28 #include <linux/module.h>
  29
  30 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,35))
  31
  32 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
  33
  34 #endif
  35
  36 #ifndef HAVE_KABI_2635_TRACEPOINT
  37
  38 #define kabi_2635_tracepoint_probe_register tracepoint_probe_register
  39 #define kabi_2635_tracepoint_probe_unregister tracepoint_probe_unregister
  40
  41 #endif /* HAVE_KABI_2635_TRACEPOINT */
  42
  43 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0))
  44
  45 #include <lttng-tracepoint.h>
  46
  47 #define lttng_wrapper_tracepoint_probe_register lttng_tracepoint_probe_register
  48 #define lttng_wrapper_tracepoint_probe_unregister lttng_tracepoint_probe_unregister
  49
  50 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)) */
  51
  52 #define lttng_wrapper_tracepoint_probe_register kabi_2635_tracepoint_probe_register
  53 #define lttng_wrapper_tracepoint_probe_unregister kabi_2635_tracepoint_probe_unregister
  54
  55 static inline
  56 int lttng_tracepoint_init(void)
  57 {
  58         return 0;
  59 }
  60
  61 static inline
  62 void lttng_tracepoint_exit(void)
  63 {
  64 }
  65
  66 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,15,0)) */
  67
  68 #ifdef CONFIG_MODULE_SIG
  69
  70 #include <linux/kallsyms.h>
  71 #include <wrapper/kallsyms.h>
  72
  73 static inline
  74 int wrapper_tracepoint_module_notify(struct notifier_block *nb,
  75                 unsigned long val, struct module *mod)
  76 {
  77         int (*tracepoint_module_notify_sym)(struct notifier_block *nb,
  78                         unsigned long val, struct module *mod);
  79
  80         tracepoint_module_notify_sym =
  81                 (void *) kallsyms_lookup_funcptr("tracepoint_module_notify");
  82         if (tracepoint_module_notify_sym) {
  83                 return tracepoint_module_notify_sym(nb, val, mod);
  84         } else {
  85                 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");
  86                 return -ENOSYS;
  87         }
  88 }
  89
  90 #endif /* CONFIG_MODULE_SIG */
  91
  92 #if 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 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 defined(CONFIG_MODULE_SIG) && defined(MODULE) */
 122
 123 #endif /* _LTTNG_WRAPPER_TRACEPOINT_H */