/*- * Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com> * Copyright (c) 2019 Mitchell Horne * 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> #include <machine/riscvreg.h> #include <sys/errno.h> #include "assym.inc" /* * Fault handler for the copy{in,out} functions below. */ ENTRY(copyio_fault) SET_FAULT_HANDLER(x0, a1) /* Clear the handler */ EXIT_USER_ACCESS(a1) copyio_fault_nopcb: li a0, EFAULT ret END(copyio_fault) /* * copycommon - common copy routine * * a0 - Source address * a1 - Destination address * a2 - Size of copy */ .macro copycommon la a6, copyio_fault /* Get the handler address */ SET_FAULT_HANDLER(a6, a7) /* Set the handler */ ENTER_USER_ACCESS(a7) li t2, XLEN_BYTES blt a2, t2, 4f /* Byte-copy if len < XLEN_BYTES */ /* * Compare lower bits of src and dest. * If they are aligned with each other, we can do word copy. */ andi t0, a0, (XLEN_BYTES-1) /* Low bits of src */ andi t1, a1, (XLEN_BYTES-1) /* Low bits of dest */ bne t0, t1, 4f /* Misaligned. Go to byte copy */ beqz t0, 2f /* Already word-aligned, skip ahead */ /* Byte copy until the first word-aligned address */ 1: lb a4, 0(a0) /* Load byte from src */ addi a0, a0, 1 sb a4, 0(a1) /* Store byte in dest */ addi a1, a1, 1 addi a2, a2, -1 /* len-- */ andi t0, a0, (XLEN_BYTES-1) bnez t0, 1b j 3f /* Copy words */ 2: ld a4, 0(a0) /* Load word from src */ addi a0, a0, XLEN_BYTES sd a4, 0(a1) /* Store word in dest */ addi a1, a1, XLEN_BYTES addi a2, a2, -XLEN_BYTES /* len -= XLEN_BYTES */ 3: bgeu a2, t2, 2b /* Again if len >= XLEN_BYTES */ /* Check if we're finished */ beqz a2, 5f /* Copy any remaining bytes */ 4: lb a4, 0(a0) /* Load byte from src */ addi a0, a0, 1 sb a4, 0(a1) /* Store byte in dest */ addi a1, a1, 1 addi a2, a2, -1 /* len-- */ bnez a2, 4b 5: EXIT_USER_ACCESS(a7) SET_FAULT_HANDLER(x0, a7) /* Clear the handler */ .endm /* * Copies from a kernel to user address * * int copyout(const void *kaddr, void *udaddr, size_t len) */ ENTRY(copyout) beqz a2, copyout_end /* If len == 0 then skip loop */ add a3, a1, a2 li a4, VM_MAXUSER_ADDRESS bgeu a3, a4, copyio_fault_nopcb copycommon copyout_end: li a0, 0 /* return 0 */ ret END(copyout) /* * Copies from a user to kernel address * * int copyin(const void *uaddr, void *kaddr, size_t len) */ ENTRY(copyin) beqz a2, copyin_end /* If len == 0 then skip loop */ add a3, a0, a2 li a4, VM_MAXUSER_ADDRESS bgeu a3, a4, copyio_fault_nopcb copycommon copyin_end: li a0, 0 /* return 0 */ ret END(copyin) /* * Copies a string from a user to kernel address * * int copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *done) */ ENTRY(copyinstr) mv a5, x0 /* count = 0 */ beqz a2, 3f /* If len == 0 then skip loop */ la a6, copyio_fault /* Get the handler address */ SET_FAULT_HANDLER(a6, a7) /* Set the handler */ ENTER_USER_ACCESS(a7) li a7, VM_MAXUSER_ADDRESS 1: bgeu a0, a7, copyio_fault lb a4, 0(a0) /* Load from uaddr */ addi a0, a0, 1 sb a4, 0(a1) /* Store in kaddr */ addi a1, a1, 1 beqz a4, 2f addi a2, a2, -1 /* len-- */ addi a5, a5, 1 /* count++ */ bnez a2, 1b 2: EXIT_USER_ACCESS(a7) SET_FAULT_HANDLER(x0, a7) /* Clear the handler */ 3: beqz a3, 4f /* Check if done != NULL */ addi a5, a5, 1 /* count++ */ sd a5, 0(a3) /* done = count */ 4: mv a0, x0 /* return 0 */ beqz a4, 5f li a0, ENAMETOOLONG 5: ret END(copyinstr)
