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 static inline long access_ok(int type, const void __user * addr, 36 unsigned long size) 37 { 38 return 1; 39 } 40 41 #define put_user __put_user 42 #define get_user __get_user 43 44 #if !defined(CONFIG_64BIT) 45 #define LDD_USER(ptr) __get_user_asm64(ptr) 46 #define STD_USER(x, ptr) __put_user_asm64(x, ptr) 47 #else 48 #define LDD_USER(ptr) __get_user_asm("ldd", ptr) 49 #define STD_USER(x, ptr) __put_user_asm("std", x, ptr) 50 #endif 51 52 /* 53 * The exception table contains two values: the first is the relative offset to 54 * the address of the instruction that is allowed to fault, and the second is 55 * the relative offset to the address of the fixup routine. Since relative 56 * addresses are used, 32bit values are sufficient even on 64bit kernel. 57 */ 58 59 #define ARCH_HAS_RELATIVE_EXTABLE 60 struct exception_table_entry { 61 int insn; /* relative address of insn that is allowed to fault. */ 62 int fixup; /* relative address of fixup routine */ 63 }; 64 65 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\ 66 ".section __ex_table,\"aw\"\n" \ 67 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \ 68 ".previous\n" 69 70 /* 71 * The page fault handler stores, in a per-cpu area, the following information 72 * if a fixup routine is available. 73 */ 74 struct exception_data { 75 unsigned long fault_ip; 76 unsigned long fault_gp; 77 unsigned long fault_space; 78 unsigned long fault_addr; 79 }; 80 81 /* 82 * load_sr2() preloads the space register %%sr2 - based on the value of 83 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which 84 * is 0), or with the current value of %%sr3 to access user space (USER_DS) 85 * memory. The following __get_user_asm() and __put_user_asm() functions have 86 * %%sr2 hard-coded to access the requested memory. 87 */ 88 #define load_sr2() \ 89 __asm__(" or,= %0,%%r0,%%r0\n\t" \ 90 " mfsp %%sr3,%0\n\t" \ 91 " mtsp %0,%%sr2\n\t" \ 92 : : "r"(get_fs()) : ) 93 94 #define __get_user(x, ptr) \ 95 ({ \ 96 register long __gu_err __asm__ ("r8") = 0; \ 97 register long __gu_val __asm__ ("r9") = 0; \ 98 \ 99 load_sr2(); \ 100 switch (sizeof(*(ptr))) { \ 101 case 1: __get_user_asm("ldb", ptr); break; \ 102 case 2: __get_user_asm("ldh", ptr); break; \ 103 case 4: __get_user_asm("ldw", ptr); break; \ 104 case 8: LDD_USER(ptr); break; \ 105 default: BUILD_BUG(); break; \ 106 } \ 107 \ 108 (x) = (__force __typeof__(*(ptr))) __gu_val; \ 109 __gu_err; \ 110 }) 111 112 #define __get_user_asm(ldx, ptr) \ 113 __asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \ 114 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\ 115 : "=r"(__gu_val), "=r"(__gu_err) \ 116 : "r"(ptr), "1"(__gu_err) \ 117 : "r1"); 118 119 #if !defined(CONFIG_64BIT) 120 121 #define __get_user_asm64(ptr) \ 122 __asm__("\n1:\tldw 0(%%sr2,%2),%0" \ 123 "\n2:\tldw 4(%%sr2,%2),%R0\n\t" \ 124 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_2)\ 125 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_get_user_skip_1)\ 126 : "=r"(__gu_val), "=r"(__gu_err) \ 127 : "r"(ptr), "1"(__gu_err) \ 128 : "r1"); 129 130 #endif /* !defined(CONFIG_64BIT) */ 131 132 133 #define __put_user(x, ptr) \ 134 ({ \ 135 register long __pu_err __asm__ ("r8") = 0; \ 136 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \ 137 \ 138 load_sr2(); \ 139 switch (sizeof(*(ptr))) { \ 140 case 1: __put_user_asm("stb", __x, ptr); break; \ 141 case 2: __put_user_asm("sth", __x, ptr); break; \ 142 case 4: __put_user_asm("stw", __x, ptr); break; \ 143 case 8: STD_USER(__x, ptr); break; \ 144 default: BUILD_BUG(); break; \ 145 } \ 146 \ 147 __pu_err; \ 148 }) 149 150 /* 151 * The "__put_user/kernel_asm()" macros tell gcc they read from memory 152 * instead of writing. This is because they do not write to any memory 153 * gcc knows about, so there are no aliasing issues. These macros must 154 * also be aware that "fixup_put_user_skip_[12]" are executed in the 155 * context of the fault, and any registers used there must be listed 156 * as clobbers. In this case only "r1" is used by the current routines. 157 * r8/r9 are already listed as err/val. 158 */ 159 160 #define __put_user_asm(stx, x, ptr) \ 161 __asm__ __volatile__ ( \ 162 "\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \ 163 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\ 164 : "=r"(__pu_err) \ 165 : "r"(ptr), "r"(x), "0"(__pu_err) \ 166 : "r1") 167 168 169 #if !defined(CONFIG_64BIT) 170 171 #define __put_user_asm64(__val, ptr) do { \ 172 __asm__ __volatile__ ( \ 173 "\n1:\tstw %2,0(%%sr2,%1)" \ 174 "\n2:\tstw %R2,4(%%sr2,%1)\n\t" \ 175 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\ 176 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\ 177 : "=r"(__pu_err) \ 178 : "r"(ptr), "r"(__val), "0"(__pu_err) \ 179 : "r1"); \ 180 } while (0) 181 182 #endif /* !defined(CONFIG_64BIT) */ 183 184 185 /* 186 * Complex access routines -- external declarations 187 */ 188 189 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long); 190 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long); 191 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long); 192 extern long strncpy_from_user(char *, const char __user *, long); 193 extern unsigned lclear_user(void __user *, unsigned long); 194 extern long lstrnlen_user(const char __user *, long); 195 /* 196 * Complex access routines -- macros 197 */ 198 #define user_addr_max() (~0UL) 199 200 #define strnlen_user lstrnlen_user 201 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL) 202 #define clear_user lclear_user 203 #define __clear_user lclear_user 204 205 unsigned long __must_check __copy_to_user(void __user *dst, const void *src, 206 unsigned long len); 207 unsigned long __must_check __copy_from_user(void *dst, const void __user *src, 208 unsigned long len); 209 unsigned long copy_in_user(void __user *dst, const void __user *src, 210 unsigned long len); 211 #define __copy_in_user copy_in_user 212 #define __copy_to_user_inatomic __copy_to_user 213 #define __copy_from_user_inatomic __copy_from_user 214 215 extern void __compiletime_error("usercopy buffer size is too small") 216 __bad_copy_user(void); 217 218 static inline void copy_user_overflow(int size, unsigned long count) 219 { 220 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); 221 } 222 223 static __always_inline unsigned long __must_check 224 copy_from_user(void *to, const void __user *from, unsigned long n) 225 { 226 int sz = __compiletime_object_size(to); 227 unsigned long ret = n; 228 229 if (likely(sz < 0 || sz >= n)) { 230 check_object_size(to, n, false); 231 ret = __copy_from_user(to, from, n); 232 } else if (!__builtin_constant_p(n)) 233 copy_user_overflow(sz, n); 234 else 235 __bad_copy_user(); 236 237 if (unlikely(ret)) 238 memset(to + (n - ret), 0, ret); 239 240 return ret; 241 } 242 243 static __always_inline unsigned long __must_check 244 copy_to_user(void __user *to, const void *from, unsigned long n) 245 { 246 int sz = __compiletime_object_size(from); 247 248 if (likely(sz < 0 || sz >= n)) { 249 check_object_size(from, n, true); 250 n = __copy_to_user(to, from, n); 251 } else if (!__builtin_constant_p(n)) 252 copy_user_overflow(sz, n); 253 else 254 __bad_copy_user(); 255 256 return n; 257 } 258 259 struct pt_regs; 260 int fixup_exception(struct pt_regs *regs); 261 262 #endif /* __PARISC_UACCESS_H */ 263