diff options
Diffstat (limited to 'sysdeps/nacl/brk.c')
-rw-r--r-- | sysdeps/nacl/brk.c | 93 |
1 files changed, 0 insertions, 93 deletions
diff --git a/sysdeps/nacl/brk.c b/sysdeps/nacl/brk.c deleted file mode 100644 index cf7aac4b20..0000000000 --- a/sysdeps/nacl/brk.c +++ /dev/null @@ -1,93 +0,0 @@ -/* brk -- Adjust the "break" at the end of initial data. NaCl version. - Copyright (C) 2015-2016 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/>. */ - -#include <errno.h> -#include <libc-internal.h> -#include <stdint.h> -#include <sys/mman.h> -#include <sys/param.h> -#include <unistd.h> - -/* sbrk.c expects this. */ -void *__curbrk; - -static uintptr_t -page_above (void *addr) -{ - return ALIGN_UP ((uintptr_t) addr, EXEC_PAGESIZE); -} - -/* Set the end of the process's data space to ADDR. - Return 0 if successful, -1 if not. */ -int -__brk (void *addr) -{ - /* The NaCl sysbrk call is deprecated, so we do not use it here. Other - libc code expects that __sbrk can be used at least a little bit, so - rather than a plain stub we have a minimal __brk implementation here. - It just uses mmap/munmap to grow or shrink the break area, punting as - soon as mmap fails to use the same contiguous area. */ - - if (__glibc_unlikely (__curbrk == NULL)) - { - /* This is the first call. We must initialize the record - of the current position. It starts out at the end of the - main program's data segment. */ - - /* XXX dynamic case??? */ - extern char _end[]; - __curbrk = _end; - } - - if (__glibc_unlikely (addr == NULL)) - /* This is a call just to ensure that __curbrk is set up. */ - return 0; - - uintptr_t old_limit = page_above (__curbrk); - uintptr_t new_limit = page_above (addr); - - if (old_limit > new_limit) - { - /* We're shrinking the old heap enough to release some pages. */ - if (__munmap ((void *) new_limit, old_limit - new_limit) != 0) - return -1; - } - else if (old_limit < new_limit) - { - /* We're growing the old heap enough to need some more pages. - See if they are available. */ - void *new_space = __mmap ((void *) old_limit, new_limit - old_limit, - PROT_READ | PROT_WRITE, MAP_ANON, -1, 0); - if (new_space != (void *) old_limit) - { - if (new_space != MAP_FAILED) - { - /* mmap chose some different place for the pages - because the contiguous area was not available. - Oh well. We can't use that. */ - __munmap (new_space, new_limit - old_limit); - __set_errno (ENOMEM); - } - return -1; - } - } - - __curbrk = addr; - return 0; -} -weak_alias (__brk, brk) |