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 KERNEL_DS ((mm_segment_t){0}) 15 #define USER_DS ((mm_segment_t){1}) 16 17 #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) 18 19 #define get_fs() (current_thread_info()->addr_limit) 20 #define set_fs(x) (current_thread_info()->addr_limit = (x)) 21 22 /* 23 * Note that since kernel addresses are in a separate address space on 24 * parisc, we don't need to do anything for access_ok(). 25 * We just let the page fault handler do the right thing. This also means 26 * that put_user is the same as __put_user, etc. 27 */ 28 29 #define access_ok(uaddr, size) \ 30 ( (uaddr) == (uaddr) ) 31 32 #define put_user __put_user 33 #define get_user __get_user 34 35 #if !defined(CONFIG_64BIT) 36 #define LDD_USER(val, ptr) __get_user_asm64(val, ptr) 37 #define STD_USER(x, ptr) __put_user_asm64(x, ptr) 38 #else 39 #define LDD_USER(val, ptr) __get_user_asm(val, "ldd", ptr) 40 #define STD_USER(x, ptr) __put_user_asm("std", x, ptr) 41 #endif 42 43 /* 44 * The exception table contains two values: the first is the relative offset to 45 * the address of the instruction that is allowed to fault, and the second is 46 * the relative offset to the address of the fixup routine. Since relative 47 * addresses are used, 32bit values are sufficient even on 64bit kernel. 48 */ 49 50 #define ARCH_HAS_RELATIVE_EXTABLE 51 struct exception_table_entry { 52 int insn; /* relative address of insn that is allowed to fault. */ 53 int fixup; /* relative address of fixup routine */ 54 }; 55 56 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\ 57 ".section __ex_table,\"aw\"\n" \ 58 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \ 59 ".previous\n" 60 61 /* 62 * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry 63 * (with lowest bit set) for which the fault handler in fixup_exception() will 64 * load -EFAULT into %r8 for a read or write fault, and zeroes the target 65 * register in case of a read fault in get_user(). 66 */ 67 #define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\ 68 ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1) 69 70 /* 71 * load_sr2() preloads the space register %%sr2 - based on the value of 72 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which 73 * is 0), or with the current value of %%sr3 to access user space (USER_DS) 74 * memory. The following __get_user_asm() and __put_user_asm() functions have 75 * %%sr2 hard-coded to access the requested memory. 76 */ 77 #define load_sr2() \ 78 __asm__(" or,= %0,%%r0,%%r0\n\t" \ 79 " mfsp %%sr3,%0\n\t" \ 80 " mtsp %0,%%sr2\n\t" \ 81 : : "r"(get_fs()) : ) 82 83 #define __get_user_internal(val, ptr) \ 84 ({ \ 85 register long __gu_err __asm__ ("r8") = 0; \ 86 \ 87 switch (sizeof(*(ptr))) { \ 88 case 1: __get_user_asm(val, "ldb", ptr); break; \ 89 case 2: __get_user_asm(val, "ldh", ptr); break; \ 90 case 4: __get_user_asm(val, "ldw", ptr); break; \ 91 case 8: LDD_USER(val, ptr); break; \ 92 default: BUILD_BUG(); \ 93 } \ 94 \ 95 __gu_err; \ 96 }) 97 98 #define __get_user(val, ptr) \ 99 ({ \ 100 load_sr2(); \ 101 __get_user_internal(val, ptr); \ 102 }) 103 104 #define __get_user_asm(val, ldx, ptr) \ 105 { \ 106 register long __gu_val; \ 107 \ 108 __asm__("1: " ldx " 0(%%sr2,%2),%0\n" \ 109 "9:\n" \ 110 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 111 : "=r"(__gu_val), "=r"(__gu_err) \ 112 : "r"(ptr), "1"(__gu_err)); \ 113 \ 114 (val) = (__force __typeof__(*(ptr))) __gu_val; \ 115 } 116 117 #if !defined(CONFIG_64BIT) 118 119 #define __get_user_asm64(val, ptr) \ 120 { \ 121 union { \ 122 unsigned long long l; \ 123 __typeof__(*(ptr)) t; \ 124 } __gu_tmp; \ 125 \ 126 __asm__(" copy %%r0,%R0\n" \ 127 "1: ldw 0(%%sr2,%2),%0\n" \ 128 "2: ldw 4(%%sr2,%2),%R0\n" \ 129 "9:\n" \ 130 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 131 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ 132 : "=&r"(__gu_tmp.l), "=r"(__gu_err) \ 133 : "r"(ptr), "1"(__gu_err)); \ 134 \ 135 (val) = __gu_tmp.t; \ 136 } 137 138 #endif /* !defined(CONFIG_64BIT) */ 139 140 141 #define __put_user_internal(x, ptr) \ 142 ({ \ 143 register long __pu_err __asm__ ("r8") = 0; \ 144 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \ 145 \ 146 switch (sizeof(*(ptr))) { \ 147 case 1: __put_user_asm("stb", __x, ptr); break; \ 148 case 2: __put_user_asm("sth", __x, ptr); break; \ 149 case 4: __put_user_asm("stw", __x, ptr); break; \ 150 case 8: STD_USER(__x, ptr); break; \ 151 default: BUILD_BUG(); \ 152 } \ 153 \ 154 __pu_err; \ 155 }) 156 157 #define __put_user(x, ptr) \ 158 ({ \ 159 load_sr2(); \ 160 __put_user_internal(x, ptr); \ 161 }) 162 163 164 /* 165 * The "__put_user/kernel_asm()" macros tell gcc they read from memory 166 * instead of writing. This is because they do not write to any memory 167 * gcc knows about, so there are no aliasing issues. These macros must 168 * also be aware that fixups are executed in the context of the fault, 169 * and any registers used there must be listed as clobbers. 170 * r8 is already listed as err. 171 */ 172 173 #define __put_user_asm(stx, x, ptr) \ 174 __asm__ __volatile__ ( \ 175 "1: " stx " %2,0(%%sr2,%1)\n" \ 176 "9:\n" \ 177 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 178 : "=r"(__pu_err) \ 179 : "r"(ptr), "r"(x), "0"(__pu_err)) 180 181 182 #if !defined(CONFIG_64BIT) 183 184 #define __put_user_asm64(__val, ptr) do { \ 185 __asm__ __volatile__ ( \ 186 "1: stw %2,0(%%sr2,%1)\n" \ 187 "2: stw %R2,4(%%sr2,%1)\n" \ 188 "9:\n" \ 189 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 190 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ 191 : "=r"(__pu_err) \ 192 : "r"(ptr), "r"(__val), "0"(__pu_err)); \ 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 unsigned lclear_user(void __user *, unsigned long); 204 extern long lstrnlen_user(const char __user *, long); 205 /* 206 * Complex access routines -- macros 207 */ 208 #define user_addr_max() (~0UL) 209 210 #define strnlen_user lstrnlen_user 211 #define clear_user lclear_user 212 #define __clear_user lclear_user 213 214 unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src, 215 unsigned long len); 216 unsigned long __must_check raw_copy_from_user(void *dst, const void __user *src, 217 unsigned long len); 218 unsigned long __must_check raw_copy_in_user(void __user *dst, const void __user *src, 219 unsigned long len); 220 #define INLINE_COPY_TO_USER 221 #define INLINE_COPY_FROM_USER 222 223 struct pt_regs; 224 int fixup_exception(struct pt_regs *regs); 225 226 #endif /* __PARISC_UACCESS_H */ 227