1 // SPDX-License-Identifier: GPL-2.0 1
2 /*
3 * Standard user space access functions based
4 * interesting things in the secondary space
5 *
6 * Copyright IBM Corp. 2006,2014
7 * Author(s): Martin Schwidefsky (schwidefs
8 * Gerald Schaefer (gerald.schae
9 */
10
11 #include <linux/uaccess.h>
12 #include <linux/export.h>
13 #include <linux/mm.h>
14 #include <asm/asm-extable.h>
15 #include <asm/ctlreg.h>
16
17 #ifdef CONFIG_DEBUG_ENTRY
18 void debug_user_asce(int exit)
19 {
20 struct ctlreg cr1, cr7;
21
22 local_ctl_store(1, &cr1);
23 local_ctl_store(7, &cr7);
24 if (cr1.val == get_lowcore()->kernel_a
25 return;
26 panic("incorrect ASCE on kernel %s\n"
27 "cr1: %016lx cr7: %016lx\n"
28 "kernel: %016lx user: %016lx\n",
29 exit ? "exit" : "entry", cr1.val
30 get_lowcore()->kernel_asce.val,
31 }
32 #endif /*CONFIG_DEBUG_ENTRY */
33
34 static unsigned long raw_copy_from_user_key(vo
35 un
36 {
37 unsigned long rem;
38 union oac spec = {
39 .oac2.key = key,
40 .oac2.as = PSW_BITS_AS_SECONDA
41 .oac2.k = 1,
42 .oac2.a = 1,
43 };
44
45 asm volatile(
46 " lr 0,%[spec]\n"
47 "0: mvcos 0(%[to]),0(%[f
48 "1: jz 5f\n"
49 " algr %[size],%[val]
50 " slgr %[from],%[val]
51 " slgr %[to],%[val]\n
52 " j 0b\n"
53 "2: la %[rem],4095(%[
54 " nr %[rem],%[val]\
55 " slgr %[rem],%[from]
56 " clgr %[size],%[rem]
57 " jnh 6f\n"
58 "3: mvcos 0(%[to]),0(%[f
59 "4: slgr %[size],%[rem]
60 " j 6f\n"
61 "5: slgr %[size],%[size
62 "6:\n"
63 EX_TABLE(0b, 2b)
64 EX_TABLE(1b, 2b)
65 EX_TABLE(3b, 6b)
66 EX_TABLE(4b, 6b)
67 : [size] "+&a" (size), [from]
68 : [val] "a" (-4096UL), [spec]
69 : "cc", "memory", "");
70 return size;
71 }
72
73 unsigned long raw_copy_from_user(void *to, con
74 {
75 return raw_copy_from_user_key(to, from
76 }
77 EXPORT_SYMBOL(raw_copy_from_user);
78
79 unsigned long _copy_from_user_key(void *to, co
80 unsigned lon
81 {
82 unsigned long res = n;
83
84 might_fault();
85 if (!should_fail_usercopy()) {
86 instrument_copy_from_user_befo
87 res = raw_copy_from_user_key(t
88 instrument_copy_from_user_afte
89 }
90 if (unlikely(res))
91 memset(to + (n - res), 0, res)
92 return res;
93 }
94 EXPORT_SYMBOL(_copy_from_user_key);
95
96 static unsigned long raw_copy_to_user_key(void
97 unsi
98 {
99 unsigned long rem;
100 union oac spec = {
101 .oac1.key = key,
102 .oac1.as = PSW_BITS_AS_SECONDA
103 .oac1.k = 1,
104 .oac1.a = 1,
105 };
106
107 asm volatile(
108 " lr 0,%[spec]\n"
109 "0: mvcos 0(%[to]),0(%[f
110 "1: jz 5f\n"
111 " algr %[size],%[val]
112 " slgr %[to],%[val]\n
113 " slgr %[from],%[val]
114 " j 0b\n"
115 "2: la %[rem],4095(%[
116 " nr %[rem],%[val]\
117 " slgr %[rem],%[to]\n
118 " clgr %[size],%[rem]
119 " jnh 6f\n"
120 "3: mvcos 0(%[to]),0(%[f
121 "4: slgr %[size],%[rem]
122 " j 6f\n"
123 "5: slgr %[size],%[size
124 "6:\n"
125 EX_TABLE(0b, 2b)
126 EX_TABLE(1b, 2b)
127 EX_TABLE(3b, 6b)
128 EX_TABLE(4b, 6b)
129 : [size] "+&a" (size), [to] "+
130 : [val] "a" (-4096UL), [spec]
131 : "cc", "memory", "");
132 return size;
133 }
134
135 unsigned long raw_copy_to_user(void __user *to
136 {
137 return raw_copy_to_user_key(to, from,
138 }
139 EXPORT_SYMBOL(raw_copy_to_user);
140
141 unsigned long _copy_to_user_key(void __user *t
142 unsigned long
143 {
144 might_fault();
145 if (should_fail_usercopy())
146 return n;
147 instrument_copy_to_user(to, from, n);
148 return raw_copy_to_user_key(to, from,
149 }
150 EXPORT_SYMBOL(_copy_to_user_key);
151
152 unsigned long __clear_user(void __user *to, un
153 {
154 unsigned long rem;
155 union oac spec = {
156 .oac1.as = PSW_BITS_AS_SECONDA
157 .oac1.a = 1,
158 };
159
160 asm volatile(
161 " lr 0,%[spec]\n"
162 "0: mvcos 0(%[to]),0(%[z
163 "1: jz 5f\n"
164 " algr %[size],%[val]
165 " slgr %[to],%[val]\n
166 " j 0b\n"
167 "2: la %[rem],4095(%[
168 " nr %[rem],%[val]\
169 " slgr %[rem],%[to]\n
170 " clgr %[size],%[rem]
171 " jnh 6f\n"
172 "3: mvcos 0(%[to]),0(%[z
173 "4: slgr %[size],%[rem]
174 " j 6f\n"
175 "5: slgr %[size],%[size
176 "6:\n"
177 EX_TABLE(0b, 2b)
178 EX_TABLE(1b, 2b)
179 EX_TABLE(3b, 6b)
180 EX_TABLE(4b, 6b)
181 : [size] "+&a" (size), [to] "+
182 : [val] "a" (-4096UL), [zeropg
183 : "cc", "memory", "");
184 return size;
185 }
186 EXPORT_SYMBOL(__clear_user);
187
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