include/stackinfo.h - master - githubmirror/glibc

include/stackinfo.h
76 строк3 KB
Paul Eggert
Update copyright dates with scripts/update-copyrights
02 янв 2026, 00:42
02 янв 2026, 00:4266f3e92
/* Details about the machine's stack: wrapper header.
   Copyright (C) 2014-2026 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef _INCLUDE_STACKINFO_H
#define _INCLUDE_STACKINFO_H	1

/* A sysdeps/.../stackinfo.h file defines details for the CPU.
   It is obliged to define either _STACK_GROWS_DOWN or _STACK_GROWS_UP.  */
#include_next <stackinfo.h>

#if defined _STACK_GROWS_DOWN && _STACK_GROWS_DOWN
# ifdef _STACK_GROWS_UP
#  error "stackinfo.h should not define both!"
# else
#  define _STACK_GROWS_UP	0
# endif
#elif defined _STACK_GROWS_UP && _STACK_GROWS_UP
# ifdef _STACK_GROWS_DOWN
#  error "stackinfo.h should not define both!"
# else
#  define _STACK_GROWS_DOWN	0
# endif
#else
# error "stackinfo.h must define _STACK_GROWS_UP or _STACK_GROWS_DOWN!"
#endif

#include <sys/mman.h>
#include <link.h>

/* ELF uses the PF_x macros to specify the segment permissions, mmap
   uses PROT_xxx.  In most cases the three macros have the values 1, 2,
   and 4 but not in a matching order.  The following macros allows
   converting from the PF_x values to PROT_xxx values.  */
#define PF_TO_PROT \
  ((PROT_READ << (PF_R * 4))						      \
   | (PROT_WRITE << (PF_W * 4))						      \
   | (PROT_EXEC << (PF_X * 4))						      \
   | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4))			      \
   | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4))			      \
   | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4)			      \
   | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4)))

static inline int
pf_to_prot (ElfW(Word) value)
{
#if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
  return (PF_TO_PROT >> ((value & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
#else
  ElfW(Word) ret = 0;
  if (value & PF_R)
    ret |= PROT_READ;
  if (value & PF_W)
    ret |= PROT_WRITE;
  if (value & PF_X)
    ret |= PROT_EXEC;
  return ret;
#endif

}

#endif  /* include/stackinfo.h */