wrapper/kallsyms.h

   1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
   2  *
   3  * wrapper/kallsyms.h
   4  *
   5  * wrapper around kallsyms_lookup_name. Implements arch-dependent code for
   6  * arches where the address of the start of the function body is different
   7  * from the pointer which can be used to call the function, e.g. ARM THUMB2.
   8  *
   9  * Copyright (C) 2011 Avik Sil (avik.sil@linaro.org)
  10  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  11  */
  12
  13 #ifndef _LTTNG_WRAPPER_KALLSYMS_H
  14 #define _LTTNG_WRAPPER_KALLSYMS_H
  15
  16 #include <linux/kallsyms.h>
  17
  18 /*
  19  * PowerPC ABIv1 needs KALLSYMS_ALL to get the function descriptor,
  20  * which is needed to perform the function call.
  21  */
  22 #if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF < 2)
  23 # ifndef CONFIG_KALLSYMS_ALL
  24 #  error "LTTng-modules requires CONFIG_KALLSYMS_ALL on PowerPC ABIv1"
  25 # endif
  26 #endif
  27
  28 static inline
  29 unsigned long kallsyms_lookup_funcptr(const char *name)
  30 {
  31         unsigned long addr;
  32
  33         addr = kallsyms_lookup_name(name);
  34 #ifdef CONFIG_ARM
  35 #ifdef CONFIG_THUMB2_KERNEL
  36         if (addr)
  37                 addr |= 1; /* set bit 0 in address for thumb mode */
  38 #endif
  39 #endif
  40         return addr;
  41 }
  42
  43 static inline
  44 unsigned long kallsyms_lookup_dataptr(const char *name)
  45 {
  46         return kallsyms_lookup_name(name);
  47 }
  48 #endif /* _LTTNG_WRAPPER_KALLSYMS_H */