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 /* 15 * Note that since kernel addresses are in a separate address space on 16 * parisc, we don't need to do anything for access_ok(). 17 * We just let the page fault handler do the right thing. This also means 18 * that put_user is the same as __put_user, etc. 19 */ 20 21 #define access_ok(uaddr, size) \ 22 ( (uaddr) == (uaddr) ) 23 24 #define put_user __put_user 25 #define get_user __get_user 26 27 #if !defined(CONFIG_64BIT) 28 #define LDD_USER(sr, val, ptr) __get_user_asm64(sr, val, ptr) 29 #define STD_USER(sr, x, ptr) __put_user_asm64(sr, x, ptr) 30 #else 31 #define LDD_USER(sr, val, ptr) __get_user_asm(sr, val, "ldd", ptr) 32 #define STD_USER(sr, x, ptr) __put_user_asm(sr, "std", x, ptr) 33 #endif 34 35 /* 36 * The exception table contains two values: the first is the relative offset to 37 * the address of the instruction that is allowed to fault, and the second is 38 * the relative offset to the address of the fixup routine. Since relative 39 * addresses are used, 32bit values are sufficient even on 64bit kernel. 40 */ 41 42 #define ARCH_HAS_RELATIVE_EXTABLE 43 struct exception_table_entry { 44 int insn; /* relative address of insn that is allowed to fault. */ 45 int fixup; /* relative address of fixup routine */ 46 }; 47 48 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\ 49 ".section __ex_table,\"aw\"\n" \ 50 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \ 51 ".previous\n" 52 53 /* 54 * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry 55 * (with lowest bit set) for which the fault handler in fixup_exception() will 56 * load -EFAULT into %r8 for a read or write fault, and zeroes the target 57 * register in case of a read fault in get_user(). 58 */ 59 #define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\ 60 ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1) 61 62 #define __get_user_internal(sr, val, ptr) \ 63 ({ \ 64 register long __gu_err __asm__ ("r8") = 0; \ 65 \ 66 switch (sizeof(*(ptr))) { \ 67 case 1: __get_user_asm(sr, val, "ldb", ptr); break; \ 68 case 2: __get_user_asm(sr, val, "ldh", ptr); break; \ 69 case 4: __get_user_asm(sr, val, "ldw", ptr); break; \ 70 case 8: LDD_USER(sr, val, ptr); break; \ 71 default: BUILD_BUG(); \ 72 } \ 73 \ 74 __gu_err; \ 75 }) 76 77 #define __get_user(val, ptr) \ 78 ({ \ 79 __get_user_internal("%%sr3,", val, ptr); \ 80 }) 81 82 #define __get_user_asm(sr, val, ldx, ptr) \ 83 { \ 84 register long __gu_val; \ 85 \ 86 __asm__("1: " ldx " 0(" sr "%2),%0\n" \ 87 "9:\n" \ 88 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 89 : "=r"(__gu_val), "=r"(__gu_err) \ 90 : "r"(ptr), "1"(__gu_err)); \ 91 \ 92 (val) = (__force __typeof__(*(ptr))) __gu_val; \ 93 } 94 95 #define HAVE_GET_KERNEL_NOFAULT 96 #define __get_kernel_nofault(dst, src, type, err_label) \ 97 { \ 98 type __z; \ 99 long __err; \ 100 __err = __get_user_internal("%%sr0,", __z, (type *)(src)); \ 101 if (unlikely(__err)) \ 102 goto err_label; \ 103 else \ 104 *(type *)(dst) = __z; \ 105 } 106 107 108 #if !defined(CONFIG_64BIT) 109 110 #define __get_user_asm64(sr, val, ptr) \ 111 { \ 112 union { \ 113 unsigned long long l; \ 114 __typeof__(*(ptr)) t; \ 115 } __gu_tmp; \ 116 \ 117 __asm__(" copy %%r0,%R0\n" \ 118 "1: ldw 0(" sr "%2),%0\n" \ 119 "2: ldw 4(" sr "%2),%R0\n" \ 120 "9:\n" \ 121 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 122 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ 123 : "=&r"(__gu_tmp.l), "=r"(__gu_err) \ 124 : "r"(ptr), "1"(__gu_err)); \ 125 \ 126 (val) = __gu_tmp.t; \ 127 } 128 129 #endif /* !defined(CONFIG_64BIT) */ 130 131 132 #define __put_user_internal(sr, x, ptr) \ 133 ({ \ 134 register long __pu_err __asm__ ("r8") = 0; \ 135 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \ 136 \ 137 switch (sizeof(*(ptr))) { \ 138 case 1: __put_user_asm(sr, "stb", __x, ptr); break; \ 139 case 2: __put_user_asm(sr, "sth", __x, ptr); break; \ 140 case 4: __put_user_asm(sr, "stw", __x, ptr); break; \ 141 case 8: STD_USER(sr, __x, ptr); break; \ 142 default: BUILD_BUG(); \ 143 } \ 144 \ 145 __pu_err; \ 146 }) 147 148 #define __put_user(x, ptr) \ 149 ({ \ 150 __put_user_internal("%%sr3,", x, ptr); \ 151 }) 152 153 #define __put_kernel_nofault(dst, src, type, err_label) \ 154 { \ 155 type __z = *(type *)(src); \ 156 long __err; \ 157 __err = __put_user_internal("%%sr0,", __z, (type *)(dst)); \ 158 if (unlikely(__err)) \ 159 goto err_label; \ 160 } 161 162 163 164 165 /* 166 * The "__put_user/kernel_asm()" macros tell gcc they read from memory 167 * instead of writing. This is because they do not write to any memory 168 * gcc knows about, so there are no aliasing issues. These macros must 169 * also be aware that fixups are executed in the context of the fault, 170 * and any registers used there must be listed as clobbers. 171 * r8 is already listed as err. 172 */ 173 174 #define __put_user_asm(sr, stx, x, ptr) \ 175 __asm__ __volatile__ ( \ 176 "1: " stx " %2,0(" sr "%1)\n" \ 177 "9:\n" \ 178 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 179 : "=r"(__pu_err) \ 180 : "r"(ptr), "r"(x), "0"(__pu_err)) 181 182 183 #if !defined(CONFIG_64BIT) 184 185 #define __put_user_asm64(sr, __val, ptr) do { \ 186 __asm__ __volatile__ ( \ 187 "1: stw %2,0(" sr "%1)\n" \ 188 "2: stw %R2,4(" sr "%1)\n" \ 189 "9:\n" \ 190 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 191 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ 192 : "=r"(__pu_err) \ 193 : "r"(ptr), "r"(__val), "0"(__pu_err)); \ 194 } while (0) 195 196 #endif /* !defined(CONFIG_64BIT) */ 197 198 199 /* 200 * Complex access routines -- external declarations 201 */ 202 203 extern long strncpy_from_user(char *, const char __user *, long); 204 extern __must_check unsigned lclear_user(void __user *, unsigned long); 205 extern __must_check long strnlen_user(const char __user *src, long n); 206 /* 207 * Complex access routines -- macros 208 */ 209 210 #define clear_user lclear_user 211 #define __clear_user lclear_user 212 213 unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src, 214 unsigned long len); 215 unsigned long __must_check raw_copy_from_user(void *dst, const void __user *src, 216 unsigned long len); 217 #define INLINE_COPY_TO_USER 218 #define INLINE_COPY_FROM_USER 219 220 struct pt_regs; 221 int fixup_exception(struct pt_regs *regs); 222 223 #endif /* __PARISC_UACCESS_H */ 224