1 /*-
2 * Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com>
3 * Copyright (c) 2019 Mitchell Horne
4 * All rights reserved.
5 *
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.
9 *
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).
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
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.
22 *
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
33 * SUCH DAMAGE.
34 */
35
36 #include <machine/asm.h>
37 __FBSDID("$FreeBSD$");
38
39 #include <machine/riscvreg.h>
40 #include <sys/errno.h>
41
42 #include "assym.inc"
43
44 /*
45 * Fault handler for the copy{in,out} functions below.
46 */
47 ENTRY(copyio_fault)
48 SET_FAULT_HANDLER(x0, a1) /* Clear the handler */
49 EXIT_USER_ACCESS(a1)
50 copyio_fault_nopcb:
51 li a0, EFAULT
52 ret
53 END(copyio_fault)
54
55 /*
56 * copycommon - common copy routine
57 *
58 * a0 - Source address
59 * a1 - Destination address
60 * a2 - Size of copy
61 */
62 .macro copycommon
63 la a6, copyio_fault /* Get the handler address */
64 SET_FAULT_HANDLER(a6, a7) /* Set the handler */
65 ENTER_USER_ACCESS(a7)
66
67 li t2, XLEN_BYTES
68 blt a2, t2, 4f /* Byte-copy if len < XLEN_BYTES */
69
70 /*
71 * Compare lower bits of src and dest.
72 * If they are aligned with each other, we can do word copy.
73 */
74 andi t0, a0, (XLEN_BYTES-1) /* Low bits of src */
75 andi t1, a1, (XLEN_BYTES-1) /* Low bits of dest */
76 bne t0, t1, 4f /* Misaligned. Go to byte copy */
77 beqz t0, 2f /* Already word-aligned, skip ahead */
78
79 /* Byte copy until the first word-aligned address */
80 1: lb a4, 0(a0) /* Load byte from src */
81 addi a0, a0, 1
82 sb a4, 0(a1) /* Store byte in dest */
83 addi a1, a1, 1
84 addi a2, a2, -1 /* len-- */
85 andi t0, a0, (XLEN_BYTES-1)
86 bnez t0, 1b
87 j 3f
88
89 /* Copy words */
90 2: ld a4, 0(a0) /* Load word from src */
91 addi a0, a0, XLEN_BYTES
92 sd a4, 0(a1) /* Store word in dest */
93 addi a1, a1, XLEN_BYTES
94 addi a2, a2, -XLEN_BYTES /* len -= XLEN_BYTES */
95 3: bgeu a2, t2, 2b /* Again if len >= XLEN_BYTES */
96
97 /* Check if we're finished */
98 beqz a2, 5f
99
100 /* Copy any remaining bytes */
101 4: lb a4, 0(a0) /* Load byte from src */
102 addi a0, a0, 1
103 sb a4, 0(a1) /* Store byte in dest */
104 addi a1, a1, 1
105 addi a2, a2, -1 /* len-- */
106 bnez a2, 4b
107
108 5: EXIT_USER_ACCESS(a7)
109 SET_FAULT_HANDLER(x0, a7) /* Clear the handler */
110 .endm
111
112 /*
113 * Copies from a kernel to user address
114 *
115 * int copyout(const void *kaddr, void *udaddr, size_t len)
116 */
117 ENTRY(copyout)
118 beqz a2, copyout_end /* If len == 0 then skip loop */
119 add a3, a1, a2
120 li a4, VM_MAXUSER_ADDRESS
121 bgt a3, a4, copyio_fault_nopcb
122
123 copycommon
124
125 copyout_end:
126 li a0, 0 /* return 0 */
127 ret
128 END(copyout)
129
130 /*
131 * Copies from a user to kernel address
132 *
133 * int copyin(const void *uaddr, void *kaddr, size_t len)
134 */
135 ENTRY(copyin)
136 beqz a2, copyin_end /* If len == 0 then skip loop */
137 add a3, a0, a2
138 li a4, VM_MAXUSER_ADDRESS
139 bgt a3, a4, copyio_fault_nopcb
140
141 copycommon
142
143 copyin_end:
144 li a0, 0 /* return 0 */
145 ret
146 END(copyin)
147
148 /*
149 * Copies a string from a user to kernel address
150 *
151 * int copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *done)
152 */
153 ENTRY(copyinstr)
154 mv a5, x0 /* count = 0 */
155 beqz a2, 3f /* If len == 0 then skip loop */
156
157 la a6, copyio_fault /* Get the handler address */
158 SET_FAULT_HANDLER(a6, a7) /* Set the handler */
159 ENTER_USER_ACCESS(a7)
160
161 li a7, VM_MAXUSER_ADDRESS
162 1: bgt a0, a7, copyio_fault
163 lb a4, 0(a0) /* Load from uaddr */
164 addi a0, a0, 1
165 sb a4, 0(a1) /* Store in kaddr */
166 addi a1, a1, 1
167 beqz a4, 2f
168 addi a2, a2, -1 /* len-- */
169 addi a5, a5, 1 /* count++ */
170 bnez a2, 1b
171
172 2: EXIT_USER_ACCESS(a7)
173 SET_FAULT_HANDLER(x0, a7) /* Clear the handler */
174
175 3: beqz a3, 4f /* Check if done != NULL */
176 addi a5, a5, 1 /* count++ */
177 sd a5, 0(a3) /* done = count */
178
179 4: mv a0, x0 /* return 0 */
180 beqz a4, 5f
181 li a0, ENAMETOOLONG
182 5:
183 ret
184 END(copyinstr)
Cache object: 1d5d9893ed4a66b1eae70a47f7459a3c
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