aboutsummaryrefslogtreecommitdiffstats
path: root/arch/s390/lib/uaccess_std.c
blob: 07deaeee14c833e20557d5a57f4799c9de261944 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/*
 *  arch/s390/lib/uaccess_std.c
 *
 *  Standard user space access functions based on mvcp/mvcs and doing
 *  interesting things in the secondary space mode.
 *
 *    Copyright (C) IBM Corp. 2006
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
 *		 Gerald Schaefer (gerald.schaefer@de.ibm.com)
 */

#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <asm/futex.h>
#include "uaccess.h"

#ifndef __s390x__
#define AHI	"ahi"
#define ALR	"alr"
#define CLR	"clr"
#define LHI	"lhi"
#define SLR	"slr"
#else
#define AHI	"aghi"
#define ALR	"algr"
#define CLR	"clgr"
#define LHI	"lghi"
#define SLR	"slgr"
#endif

size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
{
	unsigned long tmp1, tmp2;

	tmp1 = -256UL;
	asm volatile(
		"0: mvcp  0(%0,%2),0(%1),%3\n"
		"10:jz    8f\n"
		"1:"ALR"  %0,%3\n"
		"   la    %1,256(%1)\n"
		"   la    %2,256(%2)\n"
		"2: mvcp  0(%0,%2),0(%1),%3\n"
		"11:jnz   1b\n"
		"   j     8f\n"
		"3: la    %4,255(%1)\n"	/* %4 = ptr + 255 */
		"  "LHI"  %3,-4096\n"
		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
		"  "SLR"  %4,%1\n"
		"  "CLR"  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   5f\n"
		"4: mvcp  0(%4,%2),0(%1),%3\n"
		"12:"SLR"  %0,%4\n"
		"  "ALR"  %2,%4\n"
		"5:"LHI"  %4,-1\n"
		"  "ALR"  %4,%0\n"	/* copy remaining size, subtract 1 */
		"   bras  %3,7f\n"	/* memset loop */
		"   xc    0(1,%2),0(%2)\n"
		"6: xc    0(256,%2),0(%2)\n"
		"   la    %2,256(%2)\n"
		"7:"AHI"  %4,-256\n"
		"   jnm   6b\n"
		"   ex    %4,0(%3)\n"
		"   j     9f\n"
		"8:"SLR"  %0,%0\n"
		"9: \n"
		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
		EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
		: : "cc", "memory");
	return size;
}

static size_t copy_from_user_std_check(size_t size, const void __user *ptr,
				       void *x)
{
	if (size <= 1024)
		return copy_from_user_std(size, ptr, x);
	return copy_from_user_pt(size, ptr, x);
}

size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
{
	unsigned long tmp1, tmp2;

	tmp1 = -256UL;
	asm volatile(
		"0: mvcs  0(%0,%1),0(%2),%3\n"
		"7: jz    5f\n"
		"1:"ALR"  %0,%3\n"
		"   la    %1,256(%1)\n"
		"   la    %2,256(%2)\n"
		"2: mvcs  0(%0,%1),0(%2),%3\n"
		"8: jnz   1b\n"
		"   j     5f\n"
		"3: la    %4,255(%1)\n" /* %4 = ptr + 255 */
		"  "LHI"  %3,-4096\n"
		"   nr    %4,%3\n"	/* %4 = (ptr + 255) & -4096 */
		"  "SLR"  %4,%1\n"
		"  "CLR"  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   6f\n"
		"4: mvcs  0(%4,%1),0(%2),%3\n"
		"9:"SLR"  %0,%4\n"
		"   j     6f\n"
		"5:"SLR"  %0,%0\n"
		"6: \n"
		EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
		EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
		: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
		: : "cc", "memory");
	return size;
}

static size_t copy_to_user_std_check(size_t size, void __user *ptr,
				     const void *x)
{
	if (size <= 1024)
		return copy_to_user_std(size, ptr, x);
	return copy_to_user_pt(size, ptr, x);
}

static size_t copy_in_user_std(size_t size, void __user *to,
			       const void __user *from)
{
	unsigned long tmp1;

	asm volatile(
		"  "AHI"  %0,-1\n"
		"   jo    5f\n"
		"   sacf  256\n"
		"   bras  %3,3f\n"
		"0:"AHI"  %0,257\n"
		"1: mvc   0(1,%1),0(%2)\n"
		"   la    %1,1(%1)\n"
		"   la    %2,1(%2)\n"
		"  "AHI"  %0,-1\n"
		"   jnz   1b\n"
		"   j     5f\n"
		"2: mvc   0(256,%1),0(%2)\n"
		"   la    %1,256(%1)\n"
		"   la    %2,256(%2)\n"
		"3:"AHI"  %0,-256\n"
		"   jnm   2b\n"
		"4: ex    %0,1b-0b(%3)\n"
		"   sacf  0\n"
		"5: "SLR"  %0,%0\n"
		"6:\n"
		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
		: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
		: : "cc", "memory");
	return size;
}

static size_t clear_user_std(size_t size, void __user *to)
{
	unsigned long tmp1, tmp2;

	asm volatile(
		"  "AHI"  %0,-1\n"
		"   jo    5f\n"
		"   sacf  256\n"
		"   bras  %3,3f\n"
		"   xc    0(1,%1),0(%1)\n"
		"0:"AHI"  %0,257\n"
		"   la    %2,255(%1)\n" /* %2 = ptr + 255 */
		"   srl   %2,12\n"
		"   sll   %2,12\n"	/* %2 = (ptr + 255) & -4096 */
		"  "SLR"  %2,%1\n"
		"  "CLR"  %0,%2\n"	/* clear crosses next page boundary? */
		"   jnh   5f\n"
		"  "AHI"  %2,-1\n"
		"1: ex    %2,0(%3)\n"
		"  "AHI"  %2,1\n"
		"  "SLR"  %0,%2\n"
		"   j     5f\n"
		"2: xc    0(256,%1),0(%1)\n"
		"   la    %1,256(%1)\n"
		"3:"AHI"  %0,-256\n"
		"   jnm   2b\n"
		"4: ex    %0,0(%3)\n"
		"   sacf  0\n"
		"5: "SLR"  %0,%0\n"
		"6:\n"
		EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
		: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
		: : "cc", "memory");
	return size;
}

size_t strnlen_user_std(size_t size, const char __user *src)
{
	register unsigned long reg0 asm("0") = 0UL;
	unsigned long tmp1, tmp2;

	asm volatile(
		"   la    %2,0(%1)\n"
		"   la    %3,0(%0,%1)\n"
		"  "SLR"  %0,%0\n"
		"   sacf  256\n"
		"0: srst  %3,%2\n"
		"   jo    0b\n"
		"   la    %0,1(%3)\n"	/* strnlen_user results includes \0 */
		"  "SLR"  %0,%1\n"
		"1: sacf  0\n"
		EX_TABLE(0b,1b)
		: "+a" (size), "+a" (src), "=a" (tmp1), "=a" (tmp2)
		: "d" (reg0) : "cc", "memory");
	return size;
}

size_t strncpy_from_user_std(size_t size, const char __user *src, char *dst)
{
	register unsigned long reg0 asm("0") = 0UL;
	unsigned long tmp1, tmp2;

	asm volatile(
		"   la    %3,0(%1)\n"
		"   la    %4,0(%0,%1)\n"
		"   sacf  256\n"
		"0: srst  %4,%3\n"
		"   jo    0b\n"
		"   sacf  0\n"
		"   la    %0,0(%4)\n"
		"   jh    1f\n"		/* found \0 in string ? */
		"  "AHI"  %4,1\n"	/* include \0 in copy */
		"1:"SLR"  %0,%1\n"	/* %0 = return length (without \0) */
		"  "SLR"  %4,%1\n"	/* %4 = copy length (including \0) */
		"2: mvcp  0(%4,%2),0(%1),%5\n"
		"   jz    9f\n"
		"3:"AHI"  %4,-256\n"
		"   la    %1,256(%1)\n"
		"   la    %2,256(%2)\n"
		"4: mvcp  0(%4,%2),0(%1),%5\n"
		"   jnz   3b\n"
		"   j     9f\n"
		"7: sacf  0\n"
		"8:"LHI"  %0,%6\n"
		"9:\n"
		EX_TABLE(0b,7b) EX_TABLE(2b,8b) EX_TABLE(4b,8b)
		: "+a" (size), "+a" (src), "+d" (dst), "=a" (tmp1), "=a" (tmp2)
		: "d" (reg0), "K" (-EFAULT) : "cc", "memory");
	return size;
}

#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)	\
	asm volatile(							\
		"   sacf  256\n"					\
		"0: l     %1,0(%6)\n"					\
		"1:"insn						\
		"2: cs    %1,%2,0(%6)\n"				\
		"3: jl    1b\n"						\
		"   lhi   %0,0\n"					\
		"4: sacf  0\n"						\
		EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b)		\
		: "=d" (ret), "=&d" (oldval), "=&d" (newval),		\
		  "=m" (*uaddr)						\
		: "0" (-EFAULT), "d" (oparg), "a" (uaddr),		\
		  "m" (*uaddr) : "cc");

int futex_atomic_op_std(int op, int __user *uaddr, int oparg, int *old)
{
	int oldval = 0, newval, ret;

	switch (op) {
	case FUTEX_OP_SET:
		__futex_atomic_op("lr %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	case FUTEX_OP_ADD:
		__futex_atomic_op("lr %2,%1\nar %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	case FUTEX_OP_OR:
		__futex_atomic_op("lr %2,%1\nor %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	case FUTEX_OP_ANDN:
		__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	case FUTEX_OP_XOR:
		__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
				  ret, oldval, newval, uaddr, oparg);
		break;
	default:
		ret = -ENOSYS;
	}
	*old = oldval;
	return ret;
}

int futex_atomic_cmpxchg_std(int __user *uaddr, int oldval, int newval)
{
	int ret;

	asm volatile(
		"   sacf 256\n"
		"0: cs   %1,%4,0(%5)\n"
		"1: lr   %0,%1\n"
		"2: sacf 0\n"
		EX_TABLE(0b,2b) EX_TABLE(1b,2b)
		: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
		: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
		: "cc", "memory" );
	return ret;
}

struct uaccess_ops uaccess_std = {
	.copy_from_user = copy_from_user_std_check,
	.copy_from_user_small = copy_from_user_std,
	.copy_to_user = copy_to_user_std_check,
	.copy_to_user_small = copy_to_user_std,
	.copy_in_user = copy_in_user_std,
	.clear_user = clear_user_std,
	.strnlen_user = strnlen_user_std,
	.strncpy_from_user = strncpy_from_user_std,
	.futex_atomic_op = futex_atomic_op_std,
	.futex_atomic_cmpxchg = futex_atomic_cmpxchg_std,
};