1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 #ifndef __ASM_ASM_EXTABLE_H 3 #define __ASM_ASM_EXTABLE_H 4 5 #include <linux/bits.h> 6 #include <asm/gpr-num.h> 7 8 #define EX_TYPE_NONE 0 9 #define EX_TYPE_BPF 1 10 #define EX_TYPE_UACCESS_ERR_ZERO 2 11 #define EX_TYPE_KACCESS_ERR_ZERO 3 12 #define EX_TYPE_LOAD_UNALIGNED_ZEROPAD 4 13 14 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */ 15 #define EX_DATA_REG_ERR_SHIFT 0 16 #define EX_DATA_REG_ERR GENMASK(4, 0) 17 #define EX_DATA_REG_ZERO_SHIFT 5 18 #define EX_DATA_REG_ZERO GENMASK(9, 5) 19 20 /* Data fields for EX_TYPE_LOAD_UNALIGNED_ZEROPAD */ 21 #define EX_DATA_REG_DATA_SHIFT 0 22 #define EX_DATA_REG_DATA GENMASK(4, 0) 23 #define EX_DATA_REG_ADDR_SHIFT 5 24 #define EX_DATA_REG_ADDR GENMASK(9, 5) 25 26 #ifdef __ASSEMBLY__ 27 28 #define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ 29 .pushsection __ex_table, "a"; \ 30 .align 2; \ 31 .long ((insn) - .); \ 32 .long ((fixup) - .); \ 33 .short (type); \ 34 .short (data); \ 35 .popsection; 36 37 #define EX_DATA_REG(reg, gpr) \ 38 (.L__gpr_num_##gpr << EX_DATA_REG_##reg##_SHIFT) 39 40 #define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero) \ 41 __ASM_EXTABLE_RAW(insn, fixup, \ 42 EX_TYPE_UACCESS_ERR_ZERO, \ 43 ( \ 44 EX_DATA_REG(ERR, err) | \ 45 EX_DATA_REG(ZERO, zero) \ 46 )) 47 48 #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err) \ 49 _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr) 50 51 #define _ASM_EXTABLE_UACCESS(insn, fixup) \ 52 _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr) 53 54 /* 55 * Create an exception table entry for uaccess `insn`, which will branch to `fixup` 56 * when an unhandled fault is taken. 57 */ 58 .macro _asm_extable_uaccess, insn, fixup 59 _ASM_EXTABLE_UACCESS(\insn, \fixup) 60 .endm 61 62 /* 63 * Create an exception table entry for `insn` if `fixup` is provided. Otherwise 64 * do nothing. 65 */ 66 .macro _cond_uaccess_extable, insn, fixup 67 .ifnc \fixup, 68 _asm_extable_uaccess \insn, \fixup 69 .endif 70 .endm 71 72 #else /* __ASSEMBLY__ */ 73 74 #include <linux/stringify.h> 75 76 #define __ASM_EXTABLE_RAW(insn, fixup, type, data) \ 77 ".pushsection __ex_table, \"a\"\n" \ 78 ".align 2\n" \ 79 ".long ((" insn ") - .)\n" \ 80 ".long ((" fixup ") - .)\n" \ 81 ".short (" type ")\n" \ 82 ".short (" data ")\n" \ 83 ".popsection\n" 84 85 #define EX_DATA_REG(reg, gpr) \ 86 "((.L__gpr_num_" #gpr ") << " __stringify(EX_DATA_REG_##reg##_SHIFT) ")" 87 88 #define _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero) \ 89 __DEFINE_ASM_GPR_NUMS \ 90 __ASM_EXTABLE_RAW(#insn, #fixup, \ 91 __stringify(EX_TYPE_UACCESS_ERR_ZERO), \ 92 "(" \ 93 EX_DATA_REG(ERR, err) " | " \ 94 EX_DATA_REG(ZERO, zero) \ 95 ")") 96 97 #define _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, zero) \ 98 __DEFINE_ASM_GPR_NUMS \ 99 __ASM_EXTABLE_RAW(#insn, #fixup, \ 100 __stringify(EX_TYPE_KACCESS_ERR_ZERO), \ 101 "(" \ 102 EX_DATA_REG(ERR, err) " | " \ 103 EX_DATA_REG(ZERO, zero) \ 104 ")") 105 106 #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err) \ 107 _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, wzr) 108 109 #define _ASM_EXTABLE_UACCESS(insn, fixup) \ 110 _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr) 111 112 #define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err) \ 113 _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, wzr) 114 115 #define _ASM_EXTABLE_LOAD_UNALIGNED_ZEROPAD(insn, fixup, data, addr) \ 116 __DEFINE_ASM_GPR_NUMS \ 117 __ASM_EXTABLE_RAW(#insn, #fixup, \ 118 __stringify(EX_TYPE_LOAD_UNALIGNED_ZEROPAD), \ 119 "(" \ 120 EX_DATA_REG(DATA, data) " | " \ 121 EX_DATA_REG(ADDR, addr) \ 122 ")") 123 124 #endif /* __ASSEMBLY__ */ 125 126 #endif /* __ASM_ASM_EXTABLE_H */ 127