Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Standard user space access functions based on mvcp/mvcs and doing
3 * interesting things in the secondary space mode.
4 *
5 * Copyright IBM Corp. 2006
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7 * Gerald Schaefer (gerald.schaefer@de.ibm.com)
8 */
9
10#include <linux/errno.h>
11#include <linux/mm.h>
12#include <linux/uaccess.h>
13#include <asm/futex.h>
14#include "uaccess.h"
15
16#ifndef CONFIG_64BIT
17#define AHI "ahi"
18#define ALR "alr"
19#define CLR "clr"
20#define LHI "lhi"
21#define SLR "slr"
22#else
23#define AHI "aghi"
24#define ALR "algr"
25#define CLR "clgr"
26#define LHI "lghi"
27#define SLR "slgr"
28#endif
29
30size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
31{
32 unsigned long tmp1, tmp2;
33
34 tmp1 = -256UL;
35 asm volatile(
36 "0: mvcp 0(%0,%2),0(%1),%3\n"
37 "10:jz 8f\n"
38 "1:"ALR" %0,%3\n"
39 " la %1,256(%1)\n"
40 " la %2,256(%2)\n"
41 "2: mvcp 0(%0,%2),0(%1),%3\n"
42 "11:jnz 1b\n"
43 " j 8f\n"
44 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
45 " "LHI" %3,-4096\n"
46 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
47 " "SLR" %4,%1\n"
48 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
49 " jnh 5f\n"
50 "4: mvcp 0(%4,%2),0(%1),%3\n"
51 "12:"SLR" %0,%4\n"
52 " "ALR" %2,%4\n"
53 "5:"LHI" %4,-1\n"
54 " "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
55 " bras %3,7f\n" /* memset loop */
56 " xc 0(1,%2),0(%2)\n"
57 "6: xc 0(256,%2),0(%2)\n"
58 " la %2,256(%2)\n"
59 "7:"AHI" %4,-256\n"
60 " jnm 6b\n"
61 " ex %4,0(%3)\n"
62 " j 9f\n"
63 "8:"SLR" %0,%0\n"
64 "9: \n"
65 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
66 EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
67 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
68 : : "cc", "memory");
69 return size;
70}
71
72static size_t copy_from_user_std_check(size_t size, const void __user *ptr,
73 void *x)
74{
75 if (size <= 1024)
76 return copy_from_user_std(size, ptr, x);
77 return copy_from_user_pt(size, ptr, x);
78}
79
80size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
81{
82 unsigned long tmp1, tmp2;
83
84 tmp1 = -256UL;
85 asm volatile(
86 "0: mvcs 0(%0,%1),0(%2),%3\n"
87 "7: jz 5f\n"
88 "1:"ALR" %0,%3\n"
89 " la %1,256(%1)\n"
90 " la %2,256(%2)\n"
91 "2: mvcs 0(%0,%1),0(%2),%3\n"
92 "8: jnz 1b\n"
93 " j 5f\n"
94 "3: la %4,255(%1)\n" /* %4 = ptr + 255 */
95 " "LHI" %3,-4096\n"
96 " nr %4,%3\n" /* %4 = (ptr + 255) & -4096 */
97 " "SLR" %4,%1\n"
98 " "CLR" %0,%4\n" /* copy crosses next page boundary? */
99 " jnh 6f\n"
100 "4: mvcs 0(%4,%1),0(%2),%3\n"
101 "9:"SLR" %0,%4\n"
102 " j 6f\n"
103 "5:"SLR" %0,%0\n"
104 "6: \n"
105 EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
106 EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
107 : "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
108 : : "cc", "memory");
109 return size;
110}
111
112static size_t copy_to_user_std_check(size_t size, void __user *ptr,
113 const void *x)
114{
115 if (size <= 1024)
116 return copy_to_user_std(size, ptr, x);
117 return copy_to_user_pt(size, ptr, x);
118}
119
120static size_t copy_in_user_std(size_t size, void __user *to,
121 const void __user *from)
122{
123 unsigned long tmp1;
124
125 asm volatile(
126 " sacf 256\n"
127 " "AHI" %0,-1\n"
128 " jo 5f\n"
129 " bras %3,3f\n"
130 "0:"AHI" %0,257\n"
131 "1: mvc 0(1,%1),0(%2)\n"
132 " la %1,1(%1)\n"
133 " la %2,1(%2)\n"
134 " "AHI" %0,-1\n"
135 " jnz 1b\n"
136 " j 5f\n"
137 "2: mvc 0(256,%1),0(%2)\n"
138 " la %1,256(%1)\n"
139 " la %2,256(%2)\n"
140 "3:"AHI" %0,-256\n"
141 " jnm 2b\n"
142 "4: ex %0,1b-0b(%3)\n"
143 "5: "SLR" %0,%0\n"
144 "6: sacf 0\n"
145 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
146 : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
147 : : "cc", "memory");
148 return size;
149}
150
151static size_t clear_user_std(size_t size, void __user *to)
152{
153 unsigned long tmp1, tmp2;
154
155 asm volatile(
156 " sacf 256\n"
157 " "AHI" %0,-1\n"
158 " jo 5f\n"
159 " bras %3,3f\n"
160 " xc 0(1,%1),0(%1)\n"
161 "0:"AHI" %0,257\n"
162 " la %2,255(%1)\n" /* %2 = ptr + 255 */
163 " srl %2,12\n"
164 " sll %2,12\n" /* %2 = (ptr + 255) & -4096 */
165 " "SLR" %2,%1\n"
166 " "CLR" %0,%2\n" /* clear crosses next page boundary? */
167 " jnh 5f\n"
168 " "AHI" %2,-1\n"
169 "1: ex %2,0(%3)\n"
170 " "AHI" %2,1\n"
171 " "SLR" %0,%2\n"
172 " j 5f\n"
173 "2: xc 0(256,%1),0(%1)\n"
174 " la %1,256(%1)\n"
175 "3:"AHI" %0,-256\n"
176 " jnm 2b\n"
177 "4: ex %0,0(%3)\n"
178 "5: "SLR" %0,%0\n"
179 "6: sacf 0\n"
180 EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
181 : "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
182 : : "cc", "memory");
183 return size;
184}
185
186size_t strnlen_user_std(size_t size, const char __user *src)
187{
188 register unsigned long reg0 asm("0") = 0UL;
189 unsigned long tmp1, tmp2;
190
191 if (unlikely(!size))
192 return 0;
193 asm volatile(
194 " la %2,0(%1)\n"
195 " la %3,0(%0,%1)\n"
196 " "SLR" %0,%0\n"
197 " sacf 256\n"
198 "0: srst %3,%2\n"
199 " jo 0b\n"
200 " la %0,1(%3)\n" /* strnlen_user results includes \0 */
201 " "SLR" %0,%1\n"
202 "1: sacf 0\n"
203 EX_TABLE(0b,1b)
204 : "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
205 : "d" (reg0) : "cc", "memory");
206 return size;
207}
208
209size_t strncpy_from_user_std(size_t count, const char __user *src, char *dst)
210{
211 size_t done, len, offset, len_str;
212
213 if (unlikely(!count))
214 return 0;
215 done = 0;
216 do {
217 offset = (size_t)src & ~PAGE_MASK;
218 len = min(count - done, PAGE_SIZE - offset);
219 if (copy_from_user_std(len, src, dst))
220 return -EFAULT;
221 len_str = strnlen(dst, len);
222 done += len_str;
223 src += len_str;
224 dst += len_str;
225 } while ((len_str == len) && (done < count));
226 return done;
227}
228
229#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
230 asm volatile( \
231 " sacf 256\n" \
232 "0: l %1,0(%6)\n" \
233 "1:"insn \
234 "2: cs %1,%2,0(%6)\n" \
235 "3: jl 1b\n" \
236 " lhi %0,0\n" \
237 "4: sacf 0\n" \
238 EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b) \
239 : "=d" (ret), "=&d" (oldval), "=&d" (newval), \
240 "=m" (*uaddr) \
241 : "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
242 "m" (*uaddr) : "cc");
243
244int futex_atomic_op_std(int op, u32 __user *uaddr, int oparg, int *old)
245{
246 int oldval = 0, newval, ret;
247
248 switch (op) {
249 case FUTEX_OP_SET:
250 __futex_atomic_op("lr %2,%5\n",
251 ret, oldval, newval, uaddr, oparg);
252 break;
253 case FUTEX_OP_ADD:
254 __futex_atomic_op("lr %2,%1\nar %2,%5\n",
255 ret, oldval, newval, uaddr, oparg);
256 break;
257 case FUTEX_OP_OR:
258 __futex_atomic_op("lr %2,%1\nor %2,%5\n",
259 ret, oldval, newval, uaddr, oparg);
260 break;
261 case FUTEX_OP_ANDN:
262 __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
263 ret, oldval, newval, uaddr, oparg);
264 break;
265 case FUTEX_OP_XOR:
266 __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
267 ret, oldval, newval, uaddr, oparg);
268 break;
269 default:
270 ret = -ENOSYS;
271 }
272 *old = oldval;
273 return ret;
274}
275
276int futex_atomic_cmpxchg_std(u32 *uval, u32 __user *uaddr,
277 u32 oldval, u32 newval)
278{
279 int ret;
280
281 asm volatile(
282 " sacf 256\n"
283 "0: cs %1,%4,0(%5)\n"
284 "1: la %0,0\n"
285 "2: sacf 0\n"
286 EX_TABLE(0b,2b) EX_TABLE(1b,2b)
287 : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
288 : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
289 : "cc", "memory" );
290 *uval = oldval;
291 return ret;
292}
293
294struct uaccess_ops uaccess_std = {
295 .copy_from_user = copy_from_user_std_check,
296 .copy_from_user_small = copy_from_user_std,
297 .copy_to_user = copy_to_user_std_check,
298 .copy_to_user_small = copy_to_user_std,
299 .copy_in_user = copy_in_user_std,
300 .clear_user = clear_user_std,
301 .strnlen_user = strnlen_user_std,
302 .strncpy_from_user = strncpy_from_user_std,
303 .futex_atomic_op = futex_atomic_op_std,
304 .futex_atomic_cmpxchg = futex_atomic_cmpxchg_std,
305};