tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __PARISC_UACCESS_H
3#define __PARISC_UACCESS_H
4
5/*
6 * User space memory access functions
7 */
8#include <asm/page.h>
9#include <asm/cache.h>
10
11#include <linux/bug.h>
12#include <linux/string.h>
13
14#define TASK_SIZE_MAX DEFAULT_TASK_SIZE
15#include <asm/pgtable.h>
16#include <asm-generic/access_ok.h>
17
18#define put_user __put_user
19#define get_user __get_user
20
21#if !defined(CONFIG_64BIT)
22#define LDD_USER(sr, val, ptr) __get_user_asm64(sr, val, ptr)
23#define STD_USER(sr, x, ptr) __put_user_asm64(sr, x, ptr)
24#else
25#define LDD_USER(sr, val, ptr) __get_user_asm(sr, val, "ldd", ptr)
26#define STD_USER(sr, x, ptr) __put_user_asm(sr, "std", x, ptr)
27#endif
28
29/*
30 * The exception table contains two values: the first is the relative offset to
31 * the address of the instruction that is allowed to fault, and the second is
32 * the relative offset to the address of the fixup routine. Since relative
33 * addresses are used, 32bit values are sufficient even on 64bit kernel.
34 */
35
36#define ARCH_HAS_RELATIVE_EXTABLE
37struct exception_table_entry {
38 int insn; /* relative address of insn that is allowed to fault. */
39 int fixup; /* relative address of fixup routine */
40};
41
42#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
43 ".section __ex_table,\"aw\"\n" \
44 ".align 4\n" \
45 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
46 ".previous\n"
47
48/*
49 * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry
50 * (with lowest bit set) for which the fault handler in fixup_exception() will
51 * load -EFAULT into %r29 for a read or write fault, and zeroes the target
52 * register in case of a read fault in get_user().
53 */
54#define ASM_EXCEPTIONTABLE_REG 29
55#define ASM_EXCEPTIONTABLE_VAR(__variable) \
56 register long __variable __asm__ ("r29") = 0
57#define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\
58 ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1)
59
60#define __get_user_internal(sr, val, ptr) \
61({ \
62 ASM_EXCEPTIONTABLE_VAR(__gu_err); \
63 \
64 switch (sizeof(*(ptr))) { \
65 case 1: __get_user_asm(sr, val, "ldb", ptr); break; \
66 case 2: __get_user_asm(sr, val, "ldh", ptr); break; \
67 case 4: __get_user_asm(sr, val, "ldw", ptr); break; \
68 case 8: LDD_USER(sr, val, ptr); break; \
69 default: BUILD_BUG(); \
70 } \
71 \
72 __gu_err; \
73})
74
75#define __get_user(val, ptr) \
76({ \
77 __get_user_internal(SR_USER, val, ptr); \
78})
79
80#define __get_user_asm(sr, val, ldx, ptr) \
81{ \
82 register long __gu_val; \
83 \
84 __asm__("1: " ldx " 0(%%sr%2,%3),%0\n" \
85 "9:\n" \
86 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
87 : "=r"(__gu_val), "+r"(__gu_err) \
88 : "i"(sr), "r"(ptr)); \
89 \
90 (val) = (__force __typeof__(*(ptr))) __gu_val; \
91}
92
93#define __get_kernel_nofault(dst, src, type, err_label) \
94{ \
95 type __z; \
96 long __err; \
97 __err = __get_user_internal(SR_KERNEL, __z, (type *)(src)); \
98 if (unlikely(__err)) \
99 goto err_label; \
100 else \
101 *(type *)(dst) = __z; \
102}
103
104
105#if !defined(CONFIG_64BIT)
106
107#define __get_user_asm64(sr, val, ptr) \
108{ \
109 union { \
110 unsigned long long l; \
111 __typeof__(*(ptr)) t; \
112 } __gu_tmp; \
113 \
114 __asm__(" copy %%r0,%R0\n" \
115 "1: ldw 0(%%sr%2,%3),%0\n" \
116 "2: ldw 4(%%sr%2,%3),%R0\n" \
117 "9:\n" \
118 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
119 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
120 : "=&r"(__gu_tmp.l), "+r"(__gu_err) \
121 : "i"(sr), "r"(ptr)); \
122 \
123 (val) = __gu_tmp.t; \
124}
125
126#endif /* !defined(CONFIG_64BIT) */
127
128
129#define __put_user_internal(sr, x, ptr) \
130({ \
131 ASM_EXCEPTIONTABLE_VAR(__pu_err); \
132 \
133 switch (sizeof(*(ptr))) { \
134 case 1: __put_user_asm(sr, "stb", x, ptr); break; \
135 case 2: __put_user_asm(sr, "sth", x, ptr); break; \
136 case 4: __put_user_asm(sr, "stw", x, ptr); break; \
137 case 8: STD_USER(sr, x, ptr); break; \
138 default: BUILD_BUG(); \
139 } \
140 \
141 __pu_err; \
142})
143
144#define __put_user(x, ptr) \
145({ \
146 __typeof__(&*(ptr)) __ptr = ptr; \
147 __typeof__(*(__ptr)) __x = (__typeof__(*(__ptr)))(x); \
148 __put_user_internal(SR_USER, __x, __ptr); \
149})
150
151#define __put_kernel_nofault(dst, src, type, err_label) \
152{ \
153 type __z = *(type *)(src); \
154 long __err; \
155 __err = __put_user_internal(SR_KERNEL, __z, (type *)(dst)); \
156 if (unlikely(__err)) \
157 goto err_label; \
158}
159
160
161
162
163/*
164 * The "__put_user/kernel_asm()" macros tell gcc they read from memory
165 * instead of writing. This is because they do not write to any memory
166 * gcc knows about, so there are no aliasing issues. These macros must
167 * also be aware that fixups are executed in the context of the fault,
168 * and any registers used there must be listed as clobbers.
169 * The register holding the possible EFAULT error (ASM_EXCEPTIONTABLE_REG)
170 * is already listed as input and output register.
171 */
172
173#define __put_user_asm(sr, stx, x, ptr) \
174 __asm__ __volatile__ ( \
175 "1: " stx " %1,0(%%sr%2,%3)\n" \
176 "9:\n" \
177 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
178 : "+r"(__pu_err) \
179 : "r"(x), "i"(sr), "r"(ptr))
180
181
182#if !defined(CONFIG_64BIT)
183
184#define __put_user_asm64(sr, __val, ptr) do { \
185 __asm__ __volatile__ ( \
186 "1: stw %1,0(%%sr%2,%3)\n" \
187 "2: stw %R1,4(%%sr%2,%3)\n" \
188 "9:\n" \
189 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
190 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
191 : "+r"(__pu_err) \
192 : "r"(__val), "i"(sr), "r"(ptr)); \
193} while (0)
194
195#endif /* !defined(CONFIG_64BIT) */
196
197
198/*
199 * Complex access routines -- external declarations
200 */
201
202extern long strncpy_from_user(char *, const char __user *, long);
203extern __must_check unsigned lclear_user(void __user *, unsigned long);
204extern __must_check long strnlen_user(const char __user *src, long n);
205/*
206 * Complex access routines -- macros
207 */
208
209#define clear_user lclear_user
210#define __clear_user lclear_user
211
212unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src,
213 unsigned long len);
214unsigned long __must_check raw_copy_from_user(void *dst, const void __user *src,
215 unsigned long len);
216#define INLINE_COPY_TO_USER
217#define INLINE_COPY_FROM_USER
218
219struct pt_regs;
220int fixup_exception(struct pt_regs *regs);
221
222#endif /* __PARISC_UACCESS_H */