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 #include <asm/extable_64.h> 14 15 #include <asm/processor.h> 16 17 /* 18 * Sparc64 is segmented, though more like the M68K than the I386. 19 * We use the secondary ASI to address user memory, which references a 20 * completely different VM map, thus there is zero chance of the user 21 * doing something queer and tricking us into poking kernel memory. 22 * 23 * What is left here is basically what is needed for the other parts of 24 * the kernel that expect to be able to manipulate, erum, "segments". 25 * Or perhaps more properly, permissions. 26 * 27 * "For historical reasons, these macros are grossly misnamed." -Linus 28 */ 29 30 #define KERNEL_DS ((mm_segment_t) { ASI_P }) 31 #define USER_DS ((mm_segment_t) { ASI_AIUS }) /* har har har */ 32 33 #define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)}) 34 35 #define segment_eq(a, b) ((a).seg == (b).seg) 36 37 #define set_fs(val) \ 38 do { \ 39 current_thread_info()->current_ds = (val).seg; \ 40 __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \ 41 } while(0) 42 43 /* 44 * Test whether a block of memory is a valid user space address. 45 * Returns 0 if the range is valid, nonzero otherwise. 46 */ 47 static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit) 48 { 49 if (__builtin_constant_p(size)) 50 return addr > limit - size; 51 52 addr += size; 53 if (addr < size) 54 return true; 55 56 return addr > limit; 57 } 58 59 #define __range_not_ok(addr, size, limit) \ 60 ({ \ 61 __chk_user_ptr(addr); \ 62 __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ 63 }) 64 65 static inline int __access_ok(const void __user * addr, unsigned long size) 66 { 67 return 1; 68 } 69 70 static inline int access_ok(const void __user * addr, unsigned long size) 71 { 72 return 1; 73 } 74 75 void __retl_efault(void); 76 77 /* Uh, these should become the main single-value transfer routines.. 78 * They automatically use the right size if we just have the right 79 * pointer type.. 80 * 81 * This gets kind of ugly. We want to return _two_ values in "get_user()" 82 * and yet we don't want to do any pointers, because that is too much 83 * of a performance impact. Thus we have a few rather ugly macros here, 84 * and hide all the ugliness from the user. 85 */ 86 #define put_user(x, ptr) ({ \ 87 unsigned long __pu_addr = (unsigned long)(ptr); \ 88 __chk_user_ptr(ptr); \ 89 __put_user_nocheck((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr)));\ 90 }) 91 92 #define get_user(x, ptr) ({ \ 93 unsigned long __gu_addr = (unsigned long)(ptr); \ 94 __chk_user_ptr(ptr); \ 95 __get_user_nocheck((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr)));\ 96 }) 97 98 #define __put_user(x, ptr) put_user(x, ptr) 99 #define __get_user(x, ptr) get_user(x, ptr) 100 101 struct __large_struct { unsigned long buf[100]; }; 102 #define __m(x) ((struct __large_struct *)(x)) 103 104 #define __put_user_nocheck(data, addr, size) ({ \ 105 register int __pu_ret; \ 106 switch (size) { \ 107 case 1: __put_user_asm(data, b, addr, __pu_ret); break; \ 108 case 2: __put_user_asm(data, h, addr, __pu_ret); break; \ 109 case 4: __put_user_asm(data, w, addr, __pu_ret); break; \ 110 case 8: __put_user_asm(data, x, addr, __pu_ret); break; \ 111 default: __pu_ret = __put_user_bad(); break; \ 112 } \ 113 __pu_ret; \ 114 }) 115 116 #define __put_user_asm(x, size, addr, ret) \ 117 __asm__ __volatile__( \ 118 "/* Put user asm, inline. */\n" \ 119 "1:\t" "st"#size "a %1, [%2] %%asi\n\t" \ 120 "clr %0\n" \ 121 "2:\n\n\t" \ 122 ".section .fixup,#alloc,#execinstr\n\t" \ 123 ".align 4\n" \ 124 "3:\n\t" \ 125 "sethi %%hi(2b), %0\n\t" \ 126 "jmpl %0 + %%lo(2b), %%g0\n\t" \ 127 " mov %3, %0\n\n\t" \ 128 ".previous\n\t" \ 129 ".section __ex_table,\"a\"\n\t" \ 130 ".align 4\n\t" \ 131 ".word 1b, 3b\n\t" \ 132 ".previous\n\n\t" \ 133 : "=r" (ret) : "r" (x), "r" (__m(addr)), \ 134 "i" (-EFAULT)) 135 136 int __put_user_bad(void); 137 138 #define __get_user_nocheck(data, addr, size, type) ({ \ 139 register int __gu_ret; \ 140 register unsigned long __gu_val; \ 141 switch (size) { \ 142 case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \ 143 case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \ 144 case 4: __get_user_asm(__gu_val, uw, addr, __gu_ret); break; \ 145 case 8: __get_user_asm(__gu_val, x, addr, __gu_ret); break; \ 146 default: \ 147 __gu_val = 0; \ 148 __gu_ret = __get_user_bad(); \ 149 break; \ 150 } \ 151 data = (__force type) __gu_val; \ 152 __gu_ret; \ 153 }) 154 155 #define __get_user_asm(x, size, addr, ret) \ 156 __asm__ __volatile__( \ 157 "/* Get user asm, inline. */\n" \ 158 "1:\t" "ld"#size "a [%2] %%asi, %1\n\t" \ 159 "clr %0\n" \ 160 "2:\n\n\t" \ 161 ".section .fixup,#alloc,#execinstr\n\t" \ 162 ".align 4\n" \ 163 "3:\n\t" \ 164 "sethi %%hi(2b), %0\n\t" \ 165 "clr %1\n\t" \ 166 "jmpl %0 + %%lo(2b), %%g0\n\t" \ 167 " mov %3, %0\n\n\t" \ 168 ".previous\n\t" \ 169 ".section __ex_table,\"a\"\n\t" \ 170 ".align 4\n\t" \ 171 ".word 1b, 3b\n\n\t" \ 172 ".previous\n\t" \ 173 : "=r" (ret), "=r" (x) : "r" (__m(addr)), \ 174 "i" (-EFAULT)) 175 176 int __get_user_bad(void); 177 178 unsigned long __must_check raw_copy_from_user(void *to, 179 const void __user *from, 180 unsigned long size); 181 182 unsigned long __must_check raw_copy_to_user(void __user *to, 183 const void *from, 184 unsigned long size); 185 #define INLINE_COPY_FROM_USER 186 #define INLINE_COPY_TO_USER 187 188 unsigned long __must_check raw_copy_in_user(void __user *to, 189 const void __user *from, 190 unsigned long size); 191 192 unsigned long __must_check __clear_user(void __user *, unsigned long); 193 194 #define clear_user __clear_user 195 196 __must_check long strnlen_user(const char __user *str, long n); 197 198 struct pt_regs; 199 unsigned long compute_effective_address(struct pt_regs *, 200 unsigned int insn, 201 unsigned int rd); 202 203 #endif /* _ASM_UACCESS_H */ 204