projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 24371707 JM |
1 | /* |
| 2 | * arch/arm/kernel/kprobes-thumb.c | |
| 3 | * | |
| 4 | * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>. | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or modify | |
| 7 | * it under the terms of the GNU General Public License version 2 as | |
| 8 | * published by the Free Software Foundation. | |
| 9 | */ | |
| 10 | ||
| 11 | #include <linux/kernel.h> | |
| 12 | #include <linux/kprobes.h> | |
| 13 | ||
| 14 | #include "kprobes.h" | |
| 15 | ||
| eaf4f33f JM |
16 | |
| 17 | /* | |
| 18 | * True if current instruction is in an IT block. | |
| 19 | */ | |
| 20 | #define in_it_block(cpsr) ((cpsr & 0x06000c00) != 0x00000000) | |
| 21 | ||
| 22 | /* | |
| 23 | * Return the condition code to check for the currently executing instruction. | |
| 24 | * This is in ITSTATE<7:4> which is in CPSR<15:12> but is only valid if | |
| 25 | * in_it_block returns true. | |
| 26 | */ | |
| 27 | #define current_cond(cpsr) ((cpsr >> 12) & 0xf) | |
| 28 | ||
| 3f92dfed JM |
29 | static const union decode_item t16_table_1011[] = { |
| 30 | /* Miscellaneous 16-bit instructions */ | |
| 31 | ||
| 32 | /* | |
| 33 | * If-Then, and hints | |
| 34 | * 1011 1111 xxxx xxxx | |
| 35 | */ | |
| 36 | ||
| 37 | /* YIELD 1011 1111 0001 0000 */ | |
| 38 | DECODE_OR (0xffff, 0xbf10), | |
| 39 | /* SEV 1011 1111 0100 0000 */ | |
| 40 | DECODE_EMULATE (0xffff, 0xbf40, kprobe_emulate_none), | |
| 41 | /* NOP 1011 1111 0000 0000 */ | |
| 42 | /* WFE 1011 1111 0010 0000 */ | |
| 43 | /* WFI 1011 1111 0011 0000 */ | |
| 44 | DECODE_SIMULATE (0xffcf, 0xbf00, kprobe_simulate_nop), | |
| 45 | /* Unassigned hints 1011 1111 xxxx 0000 */ | |
| 46 | DECODE_REJECT (0xff0f, 0xbf00), | |
| 47 | ||
| 48 | DECODE_END | |
| 49 | }; | |
| 50 | ||
| 51 | const union decode_item kprobe_decode_thumb16_table[] = { | |
| 52 | ||
| 53 | /* | |
| 54 | * Miscellaneous 16-bit instructions | |
| 55 | * 1011 xxxx xxxx xxxx | |
| 56 | */ | |
| 57 | DECODE_TABLE (0xf000, 0xb000, t16_table_1011), | |
| 58 | ||
| 59 | DECODE_END | |
| 60 | }; | |
| 61 | ||
| eaf4f33f JM |
62 | static unsigned long __kprobes thumb_check_cc(unsigned long cpsr) |
| 63 | { | |
| 64 | if (unlikely(in_it_block(cpsr))) | |
| 65 | return kprobe_condition_checks[current_cond(cpsr)](cpsr); | |
| 66 | return true; | |
| 67 | } | |
| 68 | ||
| c6a7d97d JM |
69 | static void __kprobes thumb16_singlestep(struct kprobe *p, struct pt_regs *regs) |
| 70 | { | |
| 71 | regs->ARM_pc += 2; | |
| 72 | p->ainsn.insn_handler(p, regs); | |
| 73 | regs->ARM_cpsr = it_advance(regs->ARM_cpsr); | |
| 74 | } | |
| 75 | ||
| 76 | static void __kprobes thumb32_singlestep(struct kprobe *p, struct pt_regs *regs) | |
| 77 | { | |
| 78 | regs->ARM_pc += 4; | |
| 79 | p->ainsn.insn_handler(p, regs); | |
| 80 | regs->ARM_cpsr = it_advance(regs->ARM_cpsr); | |
| 81 | } | |
| 82 | ||
| 24371707 JM |
83 | enum kprobe_insn __kprobes |
| 84 | thumb16_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi) | |
| 85 | { | |
| c6a7d97d | 86 | asi->insn_singlestep = thumb16_singlestep; |
| eaf4f33f | 87 | asi->insn_check_cc = thumb_check_cc; |
| 3f92dfed | 88 | return kprobe_decode_insn(insn, asi, kprobe_decode_thumb16_table, true); |
| 24371707 JM |
89 | } |
| 90 | ||
| 91 | enum kprobe_insn __kprobes | |
| 92 | thumb32_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi) | |
| 93 | { | |
| c6a7d97d | 94 | asi->insn_singlestep = thumb32_singlestep; |
| eaf4f33f | 95 | asi->insn_check_cc = thumb_check_cc; |
| 24371707 JM |
96 | return INSN_REJECTED; |
| 97 | } |