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 14 #define VERIFY_READ 0 15 #define VERIFY_WRITE 1 16 17 #define KERNEL_DS ((mm_segment_t){0}) 18 #define USER_DS ((mm_segment_t){1}) 19 20 #define segment_eq(a, b) ((a).seg == (b).seg) 21 22 #define get_ds() (KERNEL_DS) 23 #define get_fs() (current_thread_info()->addr_limit) 24 #define set_fs(x) (current_thread_info()->addr_limit = (x)) 25 26 /* 27 * Note that since kernel addresses are in a separate address space on 28 * parisc, we don't need to do anything for access_ok(). 29 * We just let the page fault handler do the right thing. This also means 30 * that put_user is the same as __put_user, etc. 31 */ 32 33 static inline long access_ok(int type, const void __user * addr, 34 unsigned long size) 35 { 36 return 1; 37 } 38 39 #define put_user __put_user 40 #define get_user __get_user 41 42 #if !defined(CONFIG_64BIT) 43 #define LDD_USER(ptr) __get_user_asm64(ptr) 44 #define STD_USER(x, ptr) __put_user_asm64(x, ptr) 45 #else 46 #define LDD_USER(ptr) __get_user_asm("ldd", ptr) 47 #define STD_USER(x, ptr) __put_user_asm("std", x, ptr) 48 #endif 49 50 /* 51 * The exception table contains two values: the first is the relative offset to 52 * the address of the instruction that is allowed to fault, and the second is 53 * the relative offset to the address of the fixup routine. Since relative 54 * addresses are used, 32bit values are sufficient even on 64bit kernel. 55 */ 56 57 #define ARCH_HAS_RELATIVE_EXTABLE 58 struct exception_table_entry { 59 int insn; /* relative address of insn that is allowed to fault. */ 60 int fixup; /* relative address of fixup routine */ 61 }; 62 63 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\ 64 ".section __ex_table,\"aw\"\n" \ 65 ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \ 66 ".previous\n" 67 68 /* 69 * The page fault handler stores, in a per-cpu area, the following information 70 * if a fixup routine is available. 71 */ 72 struct exception_data { 73 unsigned long fault_ip; 74 unsigned long fault_gp; 75 unsigned long fault_space; 76 unsigned long fault_addr; 77 }; 78 79 /* 80 * load_sr2() preloads the space register %%sr2 - based on the value of 81 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which 82 * is 0), or with the current value of %%sr3 to access user space (USER_DS) 83 * memory. The following __get_user_asm() and __put_user_asm() functions have 84 * %%sr2 hard-coded to access the requested memory. 85 */ 86 #define load_sr2() \ 87 __asm__(" or,= %0,%%r0,%%r0\n\t" \ 88 " mfsp %%sr3,%0\n\t" \ 89 " mtsp %0,%%sr2\n\t" \ 90 : : "r"(get_fs()) : ) 91 92 #define __get_user(x, ptr) \ 93 ({ \ 94 register long __gu_err __asm__ ("r8") = 0; \ 95 register long __gu_val __asm__ ("r9") = 0; \ 96 \ 97 load_sr2(); \ 98 switch (sizeof(*(ptr))) { \ 99 case 1: __get_user_asm("ldb", ptr); break; \ 100 case 2: __get_user_asm("ldh", ptr); break; \ 101 case 4: __get_user_asm("ldw", ptr); break; \ 102 case 8: LDD_USER(ptr); break; \ 103 default: BUILD_BUG(); break; \ 104 } \ 105 \ 106 (x) = (__force __typeof__(*(ptr))) __gu_val; \ 107 __gu_err; \ 108 }) 109 110 #define __get_user_asm(ldx, ptr) \ 111 __asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \ 112 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\ 113 : "=r"(__gu_val), "=r"(__gu_err) \ 114 : "r"(ptr), "1"(__gu_err) \ 115 : "r1"); 116 117 #if !defined(CONFIG_64BIT) 118 119 #define __get_user_asm64(ptr) \ 120 __asm__("\n1:\tldw 0(%%sr2,%2),%0" \ 121 "\n2:\tldw 4(%%sr2,%2),%R0\n\t" \ 122 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_2)\ 123 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_get_user_skip_1)\ 124 : "=r"(__gu_val), "=r"(__gu_err) \ 125 : "r"(ptr), "1"(__gu_err) \ 126 : "r1"); 127 128 #endif /* !defined(CONFIG_64BIT) */ 129 130 131 #define __put_user(x, ptr) \ 132 ({ \ 133 register long __pu_err __asm__ ("r8") = 0; \ 134 __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \ 135 \ 136 load_sr2(); \ 137 switch (sizeof(*(ptr))) { \ 138 case 1: __put_user_asm("stb", __x, ptr); break; \ 139 case 2: __put_user_asm("sth", __x, ptr); break; \ 140 case 4: __put_user_asm("stw", __x, ptr); break; \ 141 case 8: STD_USER(__x, ptr); break; \ 142 default: BUILD_BUG(); break; \ 143 } \ 144 \ 145 __pu_err; \ 146 }) 147 148 /* 149 * The "__put_user/kernel_asm()" macros tell gcc they read from memory 150 * instead of writing. This is because they do not write to any memory 151 * gcc knows about, so there are no aliasing issues. These macros must 152 * also be aware that "fixup_put_user_skip_[12]" are executed in the 153 * context of the fault, and any registers used there must be listed 154 * as clobbers. In this case only "r1" is used by the current routines. 155 * r8/r9 are already listed as err/val. 156 */ 157 158 #define __put_user_asm(stx, x, ptr) \ 159 __asm__ __volatile__ ( \ 160 "\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \ 161 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\ 162 : "=r"(__pu_err) \ 163 : "r"(ptr), "r"(x), "0"(__pu_err) \ 164 : "r1") 165 166 167 #if !defined(CONFIG_64BIT) 168 169 #define __put_user_asm64(__val, ptr) do { \ 170 __asm__ __volatile__ ( \ 171 "\n1:\tstw %2,0(%%sr2,%1)" \ 172 "\n2:\tstw %R2,4(%%sr2,%1)\n\t" \ 173 ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\ 174 ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\ 175 : "=r"(__pu_err) \ 176 : "r"(ptr), "r"(__val), "0"(__pu_err) \ 177 : "r1"); \ 178 } while (0) 179 180 #endif /* !defined(CONFIG_64BIT) */ 181 182 183 /* 184 * Complex access routines -- external declarations 185 */ 186 187 extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long); 188 extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long); 189 extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long); 190 extern long strncpy_from_user(char *, const char __user *, long); 191 extern unsigned lclear_user(void __user *, unsigned long); 192 extern long lstrnlen_user(const char __user *, long); 193 /* 194 * Complex access routines -- macros 195 */ 196 #define user_addr_max() (~0UL) 197 198 #define strnlen_user lstrnlen_user 199 #define strlen_user(str) lstrnlen_user(str, 0x7fffffffL) 200 #define clear_user lclear_user 201 #define __clear_user lclear_user 202 203 unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len); 204 #define __copy_to_user copy_to_user 205 unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len); 206 unsigned long copy_in_user(void __user *dst, const void __user *src, 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 copy_from_user_overflow(void) 212 #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 213 __compiletime_error("copy_from_user() buffer size is not provably correct") 214 #else 215 __compiletime_warning("copy_from_user() buffer size is not provably correct") 216 #endif 217 ; 218 219 static inline unsigned long __must_check copy_from_user(void *to, 220 const void __user *from, 221 unsigned long n) 222 { 223 int sz = __compiletime_object_size(to); 224 int ret = -EFAULT; 225 226 if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n)) 227 ret = __copy_from_user(to, from, n); 228 else 229 copy_from_user_overflow(); 230 231 return ret; 232 } 233 234 struct pt_regs; 235 int fixup_exception(struct pt_regs *regs); 236 237 #endif /* __PARISC_UACCESS_H */ 238