summaryrefslogtreecommitdiff
path: root/arch/s390/lib/uaccess.c
blob: 58033dfcb6d45f4b6d28e2bd8a865729d9baf572 (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
// SPDX-License-Identifier: GPL-2.0
/*
 *  Standard user space access functions based on mvcp/mvcs and doing
 *  interesting things in the secondary space mode.
 *
 *    Copyright IBM Corp. 2006,2014
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
 *		 Gerald Schaefer (gerald.schaefer@de.ibm.com)
 */

#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <asm/asm-extable.h>

#ifdef CONFIG_DEBUG_ENTRY
void debug_user_asce(int exit)
{
	unsigned long cr1, cr7;

	__ctl_store(cr1, 1, 1);
	__ctl_store(cr7, 7, 7);
	if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
		return;
	panic("incorrect ASCE on kernel %s\n"
	      "cr1:    %016lx cr7:  %016lx\n"
	      "kernel: %016llx user: %016llx\n",
	      exit ? "exit" : "entry", cr1, cr7,
	      S390_lowcore.kernel_asce, S390_lowcore.user_asce);

}
#endif /*CONFIG_DEBUG_ENTRY */

static unsigned long raw_copy_from_user_key(void *to, const void __user *from,
					    unsigned long size, unsigned long key)
{
	unsigned long tmp1, tmp2;
	union oac spec = {
		.oac2.key = key,
		.oac2.as = PSW_BITS_AS_SECONDARY,
		.oac2.k = 1,
		.oac2.a = 1,
	};

	tmp1 = -4096UL;
	asm volatile(
		"   lr	  0,%[spec]\n"
		"0: mvcos 0(%2),0(%1),%0\n"
		"6: jz    4f\n"
		"1: algr  %0,%3\n"
		"   slgr  %1,%3\n"
		"   slgr  %2,%3\n"
		"   j     0b\n"
		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
		"   slgr  %4,%1\n"
		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   5f\n"
		"3: mvcos 0(%2),0(%1),%4\n"
		"7: slgr  %0,%4\n"
		"   j     5f\n"
		"4: slgr  %0,%0\n"
		"5:\n"
		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
		: "+a" (size), "+a" (from), "+a" (to), "+a" (tmp1), "=a" (tmp2)
		: [spec] "d" (spec.val)
		: "cc", "memory", "0");
	return size;
}

unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
	return raw_copy_from_user_key(to, from, n, 0);
}
EXPORT_SYMBOL(raw_copy_from_user);

unsigned long _copy_from_user_key(void *to, const void __user *from,
				  unsigned long n, unsigned long key)
{
	unsigned long res = n;

	might_fault();
	if (!should_fail_usercopy()) {
		instrument_copy_from_user_before(to, from, n);
		res = raw_copy_from_user_key(to, from, n, key);
		instrument_copy_from_user_after(to, from, n, res);
	}
	if (unlikely(res))
		memset(to + (n - res), 0, res);
	return res;
}
EXPORT_SYMBOL(_copy_from_user_key);

static unsigned long raw_copy_to_user_key(void __user *to, const void *from,
					  unsigned long size, unsigned long key)
{
	unsigned long tmp1, tmp2;
	union oac spec = {
		.oac1.key = key,
		.oac1.as = PSW_BITS_AS_SECONDARY,
		.oac1.k = 1,
		.oac1.a = 1,
	};

	tmp1 = -4096UL;
	asm volatile(
		"   lr	  0,%[spec]\n"
		"0: mvcos 0(%1),0(%2),%0\n"
		"6: jz    4f\n"
		"1: algr  %0,%3\n"
		"   slgr  %1,%3\n"
		"   slgr  %2,%3\n"
		"   j     0b\n"
		"2: la    %4,4095(%1)\n"/* %4 = ptr + 4095 */
		"   nr    %4,%3\n"	/* %4 = (ptr + 4095) & -4096 */
		"   slgr  %4,%1\n"
		"   clgr  %0,%4\n"	/* copy crosses next page boundary? */
		"   jnh   5f\n"
		"3: mvcos 0(%1),0(%2),%4\n"
		"7: slgr  %0,%4\n"
		"   j     5f\n"
		"4: slgr  %0,%0\n"
		"5:\n"
		EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
		: "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
		: [spec] "d" (spec.val)
		: "cc", "memory", "0");
	return size;
}

unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
	return raw_copy_to_user_key(to, from, n, 0);
}
EXPORT_SYMBOL(raw_copy_to_user);

unsigned long _copy_to_user_key(void __user *to, const void *from,
				unsigned long n, unsigned long key)
{
	might_fault();
	if (should_fail_usercopy())
		return n;
	instrument_copy_to_user(to, from, n);
	return raw_copy_to_user_key(to, from, n, key);
}
EXPORT_SYMBOL(_copy_to_user_key);

unsigned long __clear_user(void __user *to, unsigned long size)
{
	unsigned long tmp1, tmp2;
	union oac spec = {
		.oac1.as = PSW_BITS_AS_SECONDARY,
		.oac1.a = 1,
	};

	tmp1 = -4096UL;
	asm volatile(
		"   lr	  0,%[spec]\n"
		"0: mvcos 0(%1),0(%4),%0\n"
		"   jz	  4f\n"
		"1: algr  %0,%2\n"
		"   slgr  %1,%2\n"
		"   j	  0b\n"
		"2: la	  %3,4095(%1)\n"/* %4 = to + 4095 */
		"   nr	  %3,%2\n"	/* %4 = (to + 4095) & -4096 */
		"   slgr  %3,%1\n"
		"   clgr  %0,%3\n"	/* copy crosses next page boundary? */
		"   jnh	  5f\n"
		"3: mvcos 0(%1),0(%4),%3\n"
		"   slgr  %0,%3\n"
		"   j	  5f\n"
		"4: slgr  %0,%0\n"
		"5:\n"
		EX_TABLE(0b,2b) EX_TABLE(3b,5b)
		: "+a" (size), "+a" (to), "+a" (tmp1), "=a" (tmp2)
		: "a" (empty_zero_page), [spec] "d" (spec.val)
		: "cc", "memory", "0");
	return size;
}
EXPORT_SYMBOL(__clear_user);