| /* Copyright (C) 1999-2016 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 |
| <http://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> |
| |
| /* On x86 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 %%esp, %0" : "=r" (p__)); p__; }) |
| #define stackinfo_sub_sp(ptr) \ |
| ({ ptrdiff_t d__; \ |
| asm volatile ("sub %%esp, %0" : "=r" (d__) : "0" (ptr)); \ |
| d__; }) |
| |
| #endif /* stackinfo.h */ |