1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_UACCESS_H 3 #define _ASM_UACCESS_H 4 5 /* 6 * User space memory access functions 7 */ 8 9 #include <linux/compiler.h> 10 #include <linux/string.h> 11 #include <asm/asi.h> 12 #include <asm/spitfire.h> 13 14 #include <asm/processor.h> 15 16 /* 17 * Sparc64 is segmented, though more like the M68K than the I386. 18 * We use the secondary ASI to address user memory, which references a 19 * completely different VM map, thus there is zero chance of the user 20 * doing something queer and tricking us into poking kernel memory. 21 * 22 * What is left here is basically what is needed for the other parts of 23 * the kernel that expect to be able to manipulate, erum, "segments". 24 * Or perhaps more properly, permissions. 25 * 26 * "For historical reasons, these macros are grossly misnamed." -Linus 27 */ 28 29 #define KERNEL_DS ((mm_segment_t) { ASI_P }) 30 #define USER_DS ((mm_segment_t) { ASI_AIUS }) /* har har har */ 31 32 #define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)}) 33 34 #define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) 35 36 #define set_fs(val) \ 37 do { \ 38 current_thread_info()->current_ds = (val).seg; \ 39 __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \ 40 } while(0) 41 42 /* 43 * Test whether a block of memory is a valid user space address. 44 * Returns 0 if the range is valid, nonzero otherwise. 45 */ 46 static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit) 47 { 48 if (__builtin_constant_p(size)) 49 return addr > limit - size; 50 51 addr += size; 52 if (addr < size) 53 return true; 54 55 return addr > limit; 56 } 57 58 #define __range_not_ok(addr, size, limit) \ 59 ({ \ 60 __chk_user_ptr(addr); \ 61 __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ 62 }) 63 64 static inline int __access_ok(const void __user * addr, unsigned long size) 65 { 66 return 1; 67 } 68 69 static inline int access_ok(const void __user * addr, unsigned long size) 70 { 71 return 1; 72 } 73 74 void __retl_efault(void); 75 76 /* Uh, these should become the main single-value transfer routines.. 77 * They automatically use the right size if we just have the right 78 * pointer type.. 79 * 80 * This gets kind of ugly. We want to return _two_ values in "get_user()" 81 * and yet we don't want to do any pointers, because that is too much 82 * of a performance impact. Thus we have a few rather ugly macros here, 83 * and hide all the ugliness from the user. 84 */ 85 #define put_user(x, ptr) ({ \ 86 unsigned long __pu_addr = (unsigned long)(ptr); \ 87 __chk_user_ptr(ptr); \ 88 __put_user_nocheck((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr)));\ 89 }) 90 91 #define get_user(x, ptr) ({ \ 92 unsigned long __gu_addr = (unsigned long)(ptr); \ 93 __chk_user_ptr(ptr); \ 94 __get_user_nocheck((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr)));\ 95 }) 96 97 #define __put_user(x, ptr) put_user(x, ptr) 98 #define __get_user(x, ptr) get_user(x, ptr) 99 100 struct __large_struct { unsigned long buf[100]; }; 101 #define __m(x) ((struct __large_struct *)(x)) 102 103 #define __put_user_nocheck(data, addr, size) ({ \ 104 register int __pu_ret; \ 105 switch (size) { \ 106 case 1: __put_user_asm(data, b, addr, __pu_ret); break; \ 107 case 2: __put_user_asm(data, h, addr, __pu_ret); break; \ 108 case 4: __put_user_asm(data, w, addr, __pu_ret); break; \ 109 case 8: __put_user_asm(data, x, addr, __pu_ret); break; \ 110 default: __pu_ret = __put_user_bad(); break; \ 111 } \ 112 __pu_ret; \ 113 }) 114 115 #define __put_user_asm(x, size, addr, ret) \ 116 __asm__ __volatile__( \ 117 "/* Put user asm, inline. */\n" \ 118 "1:\t" "st"#size "a %1, [%2] %%asi\n\t" \ 119 "clr %0\n" \ 120 "2:\n\n\t" \ 121 ".section .fixup,#alloc,#execinstr\n\t" \ 122 ".align 4\n" \ 123 "3:\n\t" \ 124 "sethi %%hi(2b), %0\n\t" \ 125 "jmpl %0 + %%lo(2b), %%g0\n\t" \ 126 " mov %3, %0\n\n\t" \ 127 ".previous\n\t" \ 128 ".section __ex_table,\"a\"\n\t" \ 129 ".align 4\n\t" \ 130 ".word 1b, 3b\n\t" \ 131 ".previous\n\n\t" \ 132 : "=r" (ret) : "r" (x), "r" (__m(addr)), \ 133 "i" (-EFAULT)) 134 135 int __put_user_bad(void); 136 137 #define __get_user_nocheck(data, addr, size, type) ({ \ 138 register int __gu_ret; \ 139 register unsigned long __gu_val; \ 140 switch (size) { \ 141 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \ 142 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \ 143 case 4: __get_user_asm(__gu_val, uw, addr, __gu_ret); break; \ 144 case 8: __get_user_asm(__gu_val, x, addr, __gu_ret); break; \ 145 default: \ 146 __gu_val = 0; \ 147 __gu_ret = __get_user_bad(); \ 148 break; \ 149 } \ 150 data = (__force type) __gu_val; \ 151 __gu_ret; \ 152 }) 153 154 #define __get_user_asm(x, size, addr, ret) \ 155 __asm__ __volatile__( \ 156 "/* Get user asm, inline. */\n" \ 157 "1:\t" "ld"#size "a [%2] %%asi, %1\n\t" \ 158 "clr %0\n" \ 159 "2:\n\n\t" \ 160 ".section .fixup,#alloc,#execinstr\n\t" \ 161 ".align 4\n" \ 162 "3:\n\t" \ 163 "sethi %%hi(2b), %0\n\t" \ 164 "clr %1\n\t" \ 165 "jmpl %0 + %%lo(2b), %%g0\n\t" \ 166 " mov %3, %0\n\n\t" \ 167 ".previous\n\t" \ 168 ".section __ex_table,\"a\"\n\t" \ 169 ".align 4\n\t" \ 170 ".word 1b, 3b\n\n\t" \ 171 ".previous\n\t" \ 172 : "=r" (ret), "=r" (x) : "r" (__m(addr)), \ 173 "i" (-EFAULT)) 174 175 int __get_user_bad(void); 176 177 unsigned long __must_check raw_copy_from_user(void *to, 178 const void __user *from, 179 unsigned long size); 180 181 unsigned long __must_check raw_copy_to_user(void __user *to, 182 const void *from, 183 unsigned long size); 184 #define INLINE_COPY_FROM_USER 185 #define INLINE_COPY_TO_USER 186 187 unsigned long __must_check raw_copy_in_user(void __user *to, 188 const void __user *from, 189 unsigned long size); 190 191 unsigned long __must_check __clear_user(void __user *, unsigned long); 192 193 #define clear_user __clear_user 194 195 __must_check long strnlen_user(const char __user *str, long n); 196 197 struct pt_regs; 198 unsigned long compute_effective_address(struct pt_regs *, 199 unsigned int insn, 200 unsigned int rd); 201 202 #endif /* _ASM_UACCESS_H */ 203