1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * arch/arm/probes/kprobes/checkers-common.c 4 * 5 * Copyright (C) 2014 Huawei Inc. 6 */ 7 8 #include <linux/kernel.h> 9 #include "../decode.h" 10 #include "../decode-arm.h" 11 #include "checkers.h" 12 13 enum probes_insn checker_stack_use_none(probes_opcode_t insn, 14 struct arch_probes_insn *asi, 15 const struct decode_header *h) 16 { 17 asi->stack_space = 0; 18 return INSN_GOOD_NO_SLOT; 19 } 20 21 enum probes_insn checker_stack_use_unknown(probes_opcode_t insn, 22 struct arch_probes_insn *asi, 23 const struct decode_header *h) 24 { 25 asi->stack_space = -1; 26 return INSN_GOOD_NO_SLOT; 27 } 28 29 #ifdef CONFIG_THUMB2_KERNEL 30 enum probes_insn checker_stack_use_imm_0xx(probes_opcode_t insn, 31 struct arch_probes_insn *asi, 32 const struct decode_header *h) 33 { 34 int imm = insn & 0xff; 35 asi->stack_space = imm; 36 return INSN_GOOD_NO_SLOT; 37 } 38 39 /* 40 * Different from other insn uses imm8, the real addressing offset of 41 * STRD in T32 encoding should be imm8 * 4. See ARMARM description. 42 */ 43 static enum probes_insn checker_stack_use_t32strd(probes_opcode_t insn, 44 struct arch_probes_insn *asi, 45 const struct decode_header *h) 46 { 47 int imm = insn & 0xff; 48 asi->stack_space = imm << 2; 49 return INSN_GOOD_NO_SLOT; 50 } 51 #else 52 enum probes_insn checker_stack_use_imm_x0x(probes_opcode_t insn, 53 struct arch_probes_insn *asi, 54 const struct decode_header *h) 55 { 56 int imm = ((insn & 0xf00) >> 4) + (insn & 0xf); 57 asi->stack_space = imm; 58 return INSN_GOOD_NO_SLOT; 59 } 60 #endif 61 62 enum probes_insn checker_stack_use_imm_xxx(probes_opcode_t insn, 63 struct arch_probes_insn *asi, 64 const struct decode_header *h) 65 { 66 int imm = insn & 0xfff; 67 asi->stack_space = imm; 68 return INSN_GOOD_NO_SLOT; 69 } 70 71 enum probes_insn checker_stack_use_stmdx(probes_opcode_t insn, 72 struct arch_probes_insn *asi, 73 const struct decode_header *h) 74 { 75 unsigned int reglist = insn & 0xffff; 76 int pbit = insn & (1 << 24); 77 asi->stack_space = (hweight32(reglist) - (!pbit ? 1 : 0)) * 4; 78 79 return INSN_GOOD_NO_SLOT; 80 } 81 82 const union decode_action stack_check_actions[] = { 83 [STACK_USE_NONE] = {.decoder = checker_stack_use_none}, 84 [STACK_USE_UNKNOWN] = {.decoder = checker_stack_use_unknown}, 85 #ifdef CONFIG_THUMB2_KERNEL 86 [STACK_USE_FIXED_0XX] = {.decoder = checker_stack_use_imm_0xx}, 87 [STACK_USE_T32STRD] = {.decoder = checker_stack_use_t32strd}, 88 #else 89 [STACK_USE_FIXED_X0X] = {.decoder = checker_stack_use_imm_x0x}, 90 #endif 91 [STACK_USE_FIXED_XXX] = {.decoder = checker_stack_use_imm_xxx}, 92 [STACK_USE_STMDX] = {.decoder = checker_stack_use_stmdx}, 93 }; 94