diff options
Diffstat (limited to 'libc/unistd/sbrk.c')
-rw-r--r-- | libc/unistd/sbrk.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/libc/unistd/sbrk.c b/libc/unistd/sbrk.c new file mode 100644 index 0000000..a112b6c --- /dev/null +++ b/libc/unistd/sbrk.c @@ -0,0 +1,60 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +#include <unistd.h> +#include <errno.h> + + +#define SBRK_ALIGN 32 + +/* shared with brk() implementation */ +char* __bionic_brk; + +void *sbrk(ptrdiff_t increment) +{ + char* start; + char* end; + char* new_brk; + + if ( !__bionic_brk) + __bionic_brk = __brk((void*)0); + + start = (char*)(((long)__bionic_brk + SBRK_ALIGN-1) & ~(SBRK_ALIGN-1)); + end = start + increment; + + new_brk = __brk(end); + if (new_brk == (void*)-1) + return new_brk; + else if (new_brk < end) + { + errno = ENOMEM; + return (void*)-1; + } + + __bionic_brk = new_brk; + return start; +} |