wrapper/kallsyms.h

   1 #ifndef _LTTNG_WRAPPER_KALLSYMS_H
   2 #define _LTTNG_WRAPPER_KALLSYMS_H
   3
   4 /*
   5  * wrapper/kallsyms.h
   6  *
   7  * wrapper around kallsyms_lookup_name. Implements arch-dependent code for
   8  * arches where the address of the start of the function body is different
   9  * from the pointer which can be used to call the function, e.g. ARM THUMB2.
  10  *
  11  * Copyright (C) 2011 Avik Sil (avik.sil@linaro.org)
  12  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  13  *
  14  * This library is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU Lesser General Public
  16  * License as published by the Free Software Foundation; only
  17  * version 2.1 of the License.
  18  *
  19  * This library is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  22  * Lesser General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Lesser General Public
  25  * License along with this library; if not, write to the Free Software
  26  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  27  */
  28
  29 #include <linux/kallsyms.h>
  30
  31 /*
  32  * PowerPC ABIv1 needs KALLSYMS_ALL to get the function descriptor,
  33  * which is needed to perform the function call.
  34  */
  35 #if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF < 2)
  36 # ifndef CONFIG_KALLSYMS_ALL
  37 #  error "LTTng-modules requires CONFIG_KALLSYMS_ALL on PowerPC ABIv1"
  38 # endif
  39 #endif
  40
  41 static inline
  42 unsigned long kallsyms_lookup_funcptr(const char *name)
  43 {
  44         unsigned long addr;
  45
  46         addr = kallsyms_lookup_name(name);
  47 #ifdef CONFIG_ARM
  48 #ifdef CONFIG_THUMB2_KERNEL
  49         if (addr)
  50                 addr |= 1; /* set bit 0 in address for thumb mode */
  51 #endif
  52 #endif
  53         return addr;
  54 }
  55
  56 static inline
  57 unsigned long kallsyms_lookup_dataptr(const char *name)
  58 {
  59         return kallsyms_lookup_name(name);
  60 }
  61 #endif /* _LTTNG_WRAPPER_KALLSYMS_H */