2 * Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com>
3 * Copyright (c) 2019 Mitchell Horne
6 * Portions of this software were developed by SRI International and the
7 * University of Cambridge Computer Laboratory under DARPA/AFRL contract
8 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
10 * Portions of this software were developed by the University of Cambridge
11 * Computer Laboratory as part of the CTSRD Project, with support from the
12 * UK Higher Education Innovation Fund (HEIF).
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 #include <machine/asm.h>
37 #include <machine/riscvreg.h>
38 #include <sys/errno.h>
43 * Fault handler for the copy{in,out} functions below.
46 SET_FAULT_HANDLER(x0, a1) /* Clear the handler */
54 * copycommon - common copy routine
57 * a1 - Destination address
61 la a6, copyio_fault /* Get the handler address */
62 SET_FAULT_HANDLER(a6, a7) /* Set the handler */
66 blt a2, t2, 4f /* Byte-copy if len < XLEN_BYTES */
69 * Compare lower bits of src and dest.
70 * If they are aligned with each other, we can do word copy.
72 andi t0, a0, (XLEN_BYTES-1) /* Low bits of src */
73 andi t1, a1, (XLEN_BYTES-1) /* Low bits of dest */
74 bne t0, t1, 4f /* Misaligned. Go to byte copy */
75 beqz t0, 2f /* Already word-aligned, skip ahead */
77 /* Byte copy until the first word-aligned address */
78 1: lb a4, 0(a0) /* Load byte from src */
80 sb a4, 0(a1) /* Store byte in dest */
82 addi a2, a2, -1 /* len-- */
83 andi t0, a0, (XLEN_BYTES-1)
88 2: ld a4, 0(a0) /* Load word from src */
89 addi a0, a0, XLEN_BYTES
90 sd a4, 0(a1) /* Store word in dest */
91 addi a1, a1, XLEN_BYTES
92 addi a2, a2, -XLEN_BYTES /* len -= XLEN_BYTES */
93 3: bgeu a2, t2, 2b /* Again if len >= XLEN_BYTES */
95 /* Check if we're finished */
98 /* Copy any remaining bytes */
99 4: lb a4, 0(a0) /* Load byte from src */
101 sb a4, 0(a1) /* Store byte in dest */
103 addi a2, a2, -1 /* len-- */
106 5: EXIT_USER_ACCESS(a7)
107 SET_FAULT_HANDLER(x0, a7) /* Clear the handler */
111 * Copies from a kernel to user address
113 * int copyout(const void *kaddr, void *udaddr, size_t len)
116 beqz a2, copyout_end /* If len == 0 then skip loop */
118 li a4, VM_MAXUSER_ADDRESS
119 bgeu a3, a4, copyio_fault_nopcb
124 li a0, 0 /* return 0 */
129 * Copies from a user to kernel address
131 * int copyin(const void *uaddr, void *kaddr, size_t len)
134 beqz a2, copyin_end /* If len == 0 then skip loop */
136 li a4, VM_MAXUSER_ADDRESS
137 bgeu a3, a4, copyio_fault_nopcb
142 li a0, 0 /* return 0 */
147 * Copies a string from a user to kernel address
149 * int copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *done)
152 mv a5, x0 /* count = 0 */
153 beqz a2, 3f /* If len == 0 then skip loop */
155 la a6, copyio_fault /* Get the handler address */
156 SET_FAULT_HANDLER(a6, a7) /* Set the handler */
157 ENTER_USER_ACCESS(a7)
159 li a7, VM_MAXUSER_ADDRESS
160 1: bgeu a0, a7, copyio_fault
161 lb a4, 0(a0) /* Load from uaddr */
163 sb a4, 0(a1) /* Store in kaddr */
166 addi a2, a2, -1 /* len-- */
167 addi a5, a5, 1 /* count++ */
170 2: EXIT_USER_ACCESS(a7)
171 SET_FAULT_HANDLER(x0, a7) /* Clear the handler */
173 3: beqz a3, 4f /* Check if done != NULL */
174 addi a5, a5, 1 /* count++ */
175 sd a5, 0(a3) /* done = count */
177 4: mv a0, x0 /* return 0 */