1 /* $NetBSD: copyinstr.c,v 1.24 2022/10/05 08:18:00 rin Exp $ */
2
3 /*
4 * Copyright 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: copyinstr.c,v 1.24 2022/10/05 08:18:00 rin Exp $");
40
41 #include <sys/param.h>
42 #include <uvm/uvm_extern.h>
43 #include <powerpc/ibm4xx/spr.h>
44 #include <machine/pcb.h>
45
46 int
copyinstr(const void * uaddr,void * kaddr,size_t len,size_t * done)47 copyinstr(const void *uaddr, void *kaddr, size_t len, size_t *done)
48 {
49 struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
50 size_t resid;
51 int rv, msr, pid, tmp, ctx;
52 struct faultbuf env;
53
54 if (__predict_false(len == 0)) {
55 if (done)
56 *done = 0;
57 return 0;
58 }
59
60 if ((rv = setfault(&env))) {
61 curpcb->pcb_onfault = NULL;
62 if (done)
63 *done = 0;
64 return rv;
65 }
66
67 if (!(ctx = pm->pm_ctx)) {
68 /* No context -- assign it one */
69 ctx_alloc(pm);
70 ctx = pm->pm_ctx;
71 }
72
73 resid = len;
74 __asm volatile (
75 "mtctr %[resid];" /* Set up counter */
76 "mfmsr %[msr];" /* Save MSR */
77 "li %[tmp],0x20;" /* Disable IMMU */
78 "andc %[tmp],%[msr],%[tmp];"
79 "mtmsr %[tmp];"
80 "isync;"
81 MFPID(%[pid]) /* Save old PID */
82
83 "1:" MTPID(%[ctx]) /* Load user ctx */
84 "isync;"
85 "lbz %[tmp],0(%[uaddr]);" /* Load byte */
86 "addi %[uaddr],%[uaddr],1;"
87 "sync;"
88
89 MTPID(%[pid])
90 "isync;"
91 "stb %[tmp],0(%[kaddr]);" /* Store kernel byte */
92 "addi %[kaddr],%[kaddr],1;"
93 "or. %[tmp],%[tmp],%[tmp];"
94 "sync;"
95 "bdnzf eq,1b;" /* while(ctr-- && !zero) */
96
97 "mtmsr %[msr];" /* Restore MSR */
98 "isync;"
99 "mfctr %[resid];" /* Restore resid */
100
101 : [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp),
102 [resid] "+r" (resid)
103 : [ctx] "r" (ctx), [uaddr] "b" (uaddr), [kaddr] "b" (kaddr)
104 : "cr0", "ctr");
105
106 curpcb->pcb_onfault = NULL;
107 if (done)
108 *done = len - resid;
109 if (resid == 0 && (char)tmp != '\0')
110 return ENAMETOOLONG;
111 else
112 return 0;
113 }
114