include/lttng/ust-dlfcn.h

   1 #ifndef _LTTNG_UST_DLFCN_H
   2 #define _LTTNG_UST_DLFCN_H
   3
   4 /*
   5  * lttng/ust-dlfcn.h
   6  *
   7  * Copyright 2014 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * dlfcn.h compatibility layer.
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  27  * SOFTWARE.
  28  */
  29
  30 #ifdef _DLFCN_H
  31 #error "Please include lttng/ust-dlfcn.h before dlfcn.h."
  32 #endif /* _DLFCN_H */
  33
  34 #ifdef __GLIBC__
  35 /*
  36  * glibc declares dlsym() and dlerror() with __attribute__((leaf)) (see
  37  * THROW annotation). Unfortunately, this is not in sync with reality,
  38  * as those functions call the memory allocator. Work-around this glibc
  39  * bug by declaring our own symbols.
  40  *
  41  * There has been a similar issue for dlopen() and dlclose(), as
  42  * constructors and destructors are called from these functions, so they
  43  * are clearly non-leaf. Work-around the issue for those too for older
  44  * glibc where these have not been fixed.
  45  */
  46 #define dlopen glibc_dlopen_proto_lies_about_leafness
  47 #define dlclose glibc_dlclose_proto_lies_about_leafness
  48 #define dlsym glibc_dlsym_proto_lies_about_leafness
  49 #define dlerror glibc_dlerror_proto_lies_about_leafness
  50 #include <dlfcn.h>
  51 #undef dlerror
  52 #undef dlsym
  53 #undef dlclose
  54 #undef dlopen
  55
  56 extern void *dlopen(__const char *__file, int __mode);
  57 extern int dlclose(void *__handle) __nonnull ((1));
  58 extern void *dlsym(void *__restrict __handle,
  59                 __const char *__restrict __name) __nonnull ((2));
  60 extern char *dlerror(void);
  61 #else
  62 #include <dlfcn.h>
  63 #endif /* __GLIBC__ */
  64
  65 #endif /* _LTTNG_UST_DLFCN_H */