glibc/sysdeps/x86_64/stackinfo.h
Adhemerval Zanella 01bd62517c Remove tls.h inclusion from internal errno.h
The tls.h inclusion is not really required and limits possible
definition on more arch specific headers.

This is a cleanup to allow inline functions on sysdep.h, more
specifically on i386 and ia64 which requires to access some tls
definitions its own.

No semantic changes expected, checked with a build against all
affected ABIs.
2020-11-13 12:59:19 -03:00

50 lines
1.7 KiB
C

/* Copyright (C) 2001-2020 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/>. */
/* This file contains a bit of information about the stack allocation
of the processor. */
#ifndef _STACKINFO_H
#define _STACKINFO_H 1
#include <elf.h>
#ifdef __ILP32__
# define RSP_REG "esp"
#else
# define RSP_REG "rsp"
#endif
/* On x86_64 the stack grows down. */
#define _STACK_GROWS_DOWN 1
/* Default to an executable stack. PF_X can be overridden if PT_GNU_STACK is
* present, but it is presumed absent. */
#define DEFAULT_STACK_PERMS (PF_R|PF_W|PF_X)
/* Access to the stack pointer. The macros are used in alloca_account
for which they need to act as barriers as well, hence the additional
(unnecessary) parameters. */
#define stackinfo_get_sp() \
({ void *p__; asm volatile ("mov %%" RSP_REG ", %0" : "=r" (p__)); p__; })
#define stackinfo_sub_sp(ptr) \
({ ptrdiff_t d__; \
asm volatile ("sub %%" RSP_REG " , %0" : "=r" (d__) : "0" (ptr)); \
d__; })
#endif /* stackinfo.h */