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