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