glibc/sysdeps/x86_64/stackinfo.h
Paul Eggert 581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00

50 lines
1.7 KiB
C

/* Copyright (C) 2001-2022 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 */