mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-08 22:30:07 +00:00
04277e02d7
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
63 lines
2.0 KiB
C
63 lines
2.0 KiB
C
/* Copyright (C) 1991-2019 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 <stdint.h>
|
|
#include <unistd.h>
|
|
#include <libc-internal.h>
|
|
|
|
/* Defined in brk.c. */
|
|
extern void *__curbrk;
|
|
extern int __brk (void *addr);
|
|
|
|
/* Extend the process's data space by INCREMENT.
|
|
If INCREMENT is negative, shrink data space by - INCREMENT.
|
|
Return start of new space allocated, or -1 for errors. */
|
|
void *
|
|
__sbrk (intptr_t increment)
|
|
{
|
|
void *oldbrk;
|
|
|
|
/* If this is not part of the dynamic library or the library is used
|
|
via dynamic loading in a statically linked program update
|
|
__curbrk from the kernel's brk value. That way two separate
|
|
instances of __brk and __sbrk can share the heap, returning
|
|
interleaved pieces of it. */
|
|
if (__curbrk == NULL || __libc_multiple_libcs)
|
|
if (__brk (0) < 0) /* Initialize the break. */
|
|
return (void *) -1;
|
|
|
|
if (increment == 0)
|
|
return __curbrk;
|
|
|
|
oldbrk = __curbrk;
|
|
if (increment > 0
|
|
? ((uintptr_t) oldbrk + (uintptr_t) increment < (uintptr_t) oldbrk)
|
|
: ((uintptr_t) oldbrk < (uintptr_t) -increment))
|
|
{
|
|
__set_errno (ENOMEM);
|
|
return (void *) -1;
|
|
}
|
|
|
|
if (__brk (oldbrk + increment) < 0)
|
|
return (void *) -1;
|
|
|
|
return oldbrk;
|
|
}
|
|
libc_hidden_def (__sbrk)
|
|
weak_alias (__sbrk, sbrk)
|