1  /* Definitions used by AArch64 indirect function resolvers.
       2     Copyright (C) 2019-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifndef _SYS_IFUNC_H
      20  #define _SYS_IFUNC_H
      21  
      22  /* A second argument is passed to the ifunc resolver.  */
      23  #define _IFUNC_ARG_HWCAP	(1ULL << 62)
      24  
      25  /* The prototype of a gnu indirect function resolver on AArch64 is
      26  
      27       ElfW(Addr) ifunc_resolver (uint64_t, const __ifunc_arg_t *);
      28  
      29     the first argument should have the _IFUNC_ARG_HWCAP bit set and
      30     the remaining bits should match the AT_HWCAP settings.  */
      31  
      32  /* Second argument to an ifunc resolver.  */
      33  struct __ifunc_arg_t
      34  {
      35    unsigned long _size; /* Size of the struct, so it can grow.  */
      36    unsigned long _hwcap;
      37    unsigned long _hwcap2;
      38  };
      39  
      40  typedef struct __ifunc_arg_t __ifunc_arg_t;
      41  
      42  #endif