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 37 struct 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 */ 201 202 extern long strncpy_from_user(char *, const char __user *, long); 203 extern __must_check unsigned lclear_user(void __user *, unsigned long); 204 extern __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 211 212 unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src, 213 unsigned long len); 214 unsigned 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 218 219 struct pt_regs; 220 int fixup_exception(struct pt_regs *regs); 221 222 #endif /* __PARISC_UACCESS_H */ 223