diff options
Diffstat (limited to 'lib/libc/riscv/sys/brk.S')
| -rw-r--r-- | lib/libc/riscv/sys/brk.S | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/lib/libc/riscv/sys/brk.S b/lib/libc/riscv/sys/brk.S new file mode 100644 index 0000000..4ecd923 --- /dev/null +++ b/lib/libc/riscv/sys/brk.S @@ -0,0 +1,79 @@ +/*- + * Copyright (c) 2015 Ruslan Bukin <br@bsdpad.com> + * All rights reserved. + * + * Portions of this software were developed by SRI International and the + * University of Cambridge Computer Laboratory under DARPA/AFRL contract + * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme. + * + * Portions of this software were developed by the University of Cambridge + * Computer Laboratory as part of the CTSRD Project, with support from the + * UK Higher Education Innovation Fund (HEIF). + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. 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 AUTHOR 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 AUTHOR 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 <machine/asm.h> +__FBSDID("$FreeBSD$"); + +#include "SYS.h" + + .globl _C_LABEL(_end) + + .data + .align 3 + .globl _C_LABEL(minbrk) + .type _C_LABEL(minbrk), %object +_C_LABEL(minbrk): + .quad _C_LABEL(_end) + + .text +/* + * int brk(const void *addr); + */ +ENTRY(_brk) + WEAK_REFERENCE(_brk, brk) + + /* Load the address of minbrk */ + la a3, minbrk + ld a2, 0(a3) + + /* Validate the address */ + bge a0, a2, 1f + /* Invalid, set it to the minimum */ + mv a0, a2 + + /* Backup the new address */ +1: mv a4, a0 + + /* Update for this value, will overwrite a0 and a1 */ + _SYSCALL(break) + bnez t0, cerror + + /* Store the new curbrk value */ + la a2, curbrk + sd a4, 0(a2) + + /* Return success */ + li a0, 0 + ret +END(_brk) |
