1 #ifndef __PARISC_UACCESS_H 2 #define __PARISC_UACCESS_H 3 4 /* 5 * User space memory access functions 6 */ 7 #include <asm/page.h> 8 #include <asm/cache.h> 9 #include <asm/errno.h> 10 #include <asm-generic/uaccess-unaligned.h> 11 12 #include <linux/bug.h> 13 #include <linux/string.h> 14 #include <linux/thread_info.h> 15 16 #define VERIFY_READ 0 17 #define VERIFY_WRITE 1 18 19 #define KERNEL_DS ((mm_segment_t){0}) 20 #define USER_DS ((mm_segment_t){1}) 21 22 #define segment_eq(a, b) ((a).seg == (b).seg) 23 24 #define get_ds() (KERNEL_DS) 25 #define get_fs() (current_thread_info()->addr_limit) 26 #define set_fs(x) (current_thread_info()->addr_limit = (x)) 27 28 /* 29 * Note that since kernel addresses are in a separate address space on 30 * parisc, we don't need to do anything for access_ok(). 31 * We just let the page fault handler do the right thing. This also means 32 * that put_user is the same as __put_user, etc. 33 */ 34 35 #define access_ok(type, uaddr, size) \ 36 ( (uaddr) == (uaddr) ) 37 38 #define put_user __put_user 39 #define get_user __get_user 40 41 #if !defined(CONFIG_64BIT) 42 #define LDD_USER(ptr) __get_user_asm64(ptr) 43 #define STD_USER(x, ptr) __put_user_asm64(x, ptr) 44 #else 45 #define LDD_USER(ptr) __get_user_asm("ldd", ptr) 46 #define STD_USER(x, ptr) __put_user_asm("std", x, ptr) 47 #endif 48 49 /* 50 * The exception table contains two values: the first is the relative offset to 51 * the address of the instruction that is allowed to fault, and the second is 52 * the relative offset to the address of the fixup routine. Since relative 53 * addresses are used, 32bit values are sufficient even on 64bit kernel. 54 */ 55 56 #define ARCH_HAS_RELATIVE_EXTABLE 57 struct exception_table_entry { 58 int insn; /* relative address of insn that is allowed to fault. */ 59 int fixup; /* relative address of fixup routine */ 60 }; 61 62 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\ 63 ".section __ex_table,\"aw\"\n" \ 64 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \ 65 ".previous\n" 66 67 /* 68 * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry 69 * (with lowest bit set) for which the fault handler in fixup_exception() will 70 * load -EFAULT into %r8 for a read or write fault, and zeroes the target 71 * register in case of a read fault in get_user(). 72 */ 73 #define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\ 74 ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1) 75 76 /* 77 * The page fault handler stores, in a per-cpu area, the following information 78 * if a fixup routine is available. 79 */ 80 struct exception_data { 81 unsigned long fault_ip; 82 unsigned long fault_gp; 83 unsigned long fault_space; 84 unsigned long fault_addr; 85 }; 86 87 /* 88 * load_sr2() preloads the space register %%sr2 - based on the value of 89 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which 90 * is 0), or with the current value of %%sr3 to access user space (USER_DS) 91 * memory. The following __get_user_asm() and __put_user_asm() functions have 92 * %%sr2 hard-coded to access the requested memory. 93 */ 94 #define load_sr2() \ 95 __asm__(" or,= %0,%%r0,%%r0\n\t" \ 96 " mfsp %%sr3,%0\n\t" \ 97 " mtsp %0,%%sr2\n\t" \ 98 : : "r"(get_fs()) : ) 99 100 #define __get_user(x, ptr) \ 101 ({ \ 102 register long __gu_err __asm__ ("r8") = 0; \ 103 register long __gu_val; \ 104 \ 105 load_sr2(); \ 106 switch (sizeof(*(ptr))) { \ 107 case 1: __get_user_asm("ldb", ptr); break; \ 108 case 2: __get_user_asm("ldh", ptr); break; \ 109 case 4: __get_user_asm("ldw", ptr); break; \ 110 case 8: LDD_USER(ptr); break; \ 111 default: BUILD_BUG(); break; \ 112 } \ 113 \ 114 (x) = (__force __typeof__(*(ptr))) __gu_val; \ 115 __gu_err; \ 116 }) 117 118 #define __get_user_asm(ldx, ptr) \ 119 __asm__("1: " ldx " 0(%%sr2,%2),%0\n" \ 120 "9:\n" \ 121 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 122 : "=r"(__gu_val), "=r"(__gu_err) \ 123 : "r"(ptr), "1"(__gu_err)); 124 125 #if !defined(CONFIG_64BIT) 126 127 #define __get_user_asm64(ptr) \ 128 __asm__(" copy %%r0,%R0\n" \ 129 "1: ldw 0(%%sr2,%2),%0\n" \ 130 "2: ldw 4(%%sr2,%2),%R0\n" \ 131 "9:\n" \ 132 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 133 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ 134 : "=r"(__gu_val), "=r"(__gu_err) \ 135 : "r"(ptr), "1"(__gu_err)); 136 137 #endif /* !defined(CONFIG_64BIT) */ 138 139 140 #define __put_user(x, ptr) \ 141 ({ \ 142 register long __pu_err __asm__ ("r8") = 0; \ 143 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \ 144 \ 145 load_sr2(); \ 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(); break; \ 152 } \ 153 \ 154 __pu_err; \ 155 }) 156 157 /* 158 * The "__put_user/kernel_asm()" macros tell gcc they read from memory 159 * instead of writing. This is because they do not write to any memory 160 * gcc knows about, so there are no aliasing issues. These macros must 161 * also be aware that fixups are executed in the context of the fault, 162 * and any registers used there must be listed as clobbers. 163 * r8 is already listed as err. 164 */ 165 166 #define __put_user_asm(stx, x, ptr) \ 167 __asm__ __volatile__ ( \ 168 "1: " stx " %2,0(%%sr2,%1)\n" \ 169 "9:\n" \ 170 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 171 : "=r"(__pu_err) \ 172 : "r"(ptr), "r"(x), "0"(__pu_err)) 173 174 175 #if !defined(CONFIG_64BIT) 176 177 #define __put_user_asm64(__val, ptr) do { \ 178 __asm__ __volatile__ ( \ 179 "1: stw %2,0(%%sr2,%1)\n" \ 180 "2: stw %R2,4(%%sr2,%1)\n" \ 181 "9:\n" \ 182 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ 183 ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ 184 : "=r"(__pu_err) \ 185 : "r"(ptr), "r"(__val), "0"(__pu_err)); \ 186 } while (0) 187 188 #endif /* !defined(CONFIG_64BIT) */ 189 190 191 /* 192 * Complex access routines -- external declarations 193 */ 194 195 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long); 196 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long); 197 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long); 198 extern long strncpy_from_user(char *, const char __user *, long); 199 extern unsigned lclear_user(void __user *, unsigned long); 200 extern long lstrnlen_user(const char __user *, long); 201 /* 202 * Complex access routines -- macros 203 */ 204 #define user_addr_max() (~0UL) 205 206 #define strnlen_user lstrnlen_user 207 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL) 208 #define clear_user lclear_user 209 #define __clear_user lclear_user 210 211 unsigned long __must_check __copy_to_user(void __user *dst, const void *src, 212 unsigned long len); 213 unsigned long __must_check __copy_from_user(void *dst, const void __user *src, 214 unsigned long len); 215 unsigned long copy_in_user(void __user *dst, const void __user *src, 216 unsigned long len); 217 #define __copy_in_user copy_in_user 218 #define __copy_to_user_inatomic __copy_to_user 219 #define __copy_from_user_inatomic __copy_from_user 220 221 extern void __compiletime_error("usercopy buffer size is too small") 222 __bad_copy_user(void); 223 224 static inline void copy_user_overflow(int size, unsigned long count) 225 { 226 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); 227 } 228 229 static __always_inline unsigned long __must_check 230 copy_from_user(void *to, const void __user *from, unsigned long n) 231 { 232 int sz = __compiletime_object_size(to); 233 unsigned long ret = n; 234 235 if (likely(sz < 0 || sz >= n)) { 236 check_object_size(to, n, false); 237 ret = __copy_from_user(to, from, n); 238 } else if (!__builtin_constant_p(n)) 239 copy_user_overflow(sz, n); 240 else 241 __bad_copy_user(); 242 243 if (unlikely(ret)) 244 memset(to + (n - ret), 0, ret); 245 246 return ret; 247 } 248 249 static __always_inline unsigned long __must_check 250 copy_to_user(void __user *to, const void *from, unsigned long n) 251 { 252 int sz = __compiletime_object_size(from); 253 254 if (likely(sz < 0 || sz >= n)) { 255 check_object_size(from, n, true); 256 n = __copy_to_user(to, from, n); 257 } else if (!__builtin_constant_p(n)) 258 copy_user_overflow(sz, n); 259 else 260 __bad_copy_user(); 261 262 return n; 263 } 264 265 struct pt_regs; 266 int fixup_exception(struct pt_regs *regs); 267 268 #endif /* __PARISC_UACCESS_H */ 269