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| author | Jon Medhurst | 2011-07-02 17:00:09 +0200 |
|---|---|---|
| committer | Tixy | 2011-07-13 19:32:44 +0200 |
| commit | f8695142820f3cb3bc97444a240eec5375a2b107 (patch) | |
| tree | 84f7d494f71bfa879ab501deba8487ddd1760cc5 /arch/arm/kernel/kprobes-thumb.c | |
| parent | ARM: kprobes: Decode 16-bit Thumb special data instructions (diff) | |
| download | kernel-qcow2-linux-f8695142820f3cb3bc97444a240eec5375a2b107.tar.gz kernel-qcow2-linux-f8695142820f3cb3bc97444a240eec5375a2b107.tar.xz kernel-qcow2-linux-f8695142820f3cb3bc97444a240eec5375a2b107.zip | |
ARM: kprobes: Decode 16-bit Thumb load and store instructions
Most of these instructions only operate on the low registers R0-R7
so they can make use of t16_emulate_loregs_rwflags.
The instructions which use SP or PC for addressing have their own
simulation functions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm/kernel/kprobes-thumb.c')
| -rw-r--r-- | arch/arm/kernel/kprobes-thumb.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/arm/kernel/kprobes-thumb.c b/arch/arm/kernel/kprobes-thumb.c index cd4d03d19950..632a5e8f5977 100644 --- a/arch/arm/kernel/kprobes-thumb.c +++ b/arch/arm/kernel/kprobes-thumb.c @@ -51,6 +51,29 @@ t16_simulate_bxblx(struct kprobe *p, struct pt_regs *regs) bx_write_pc(rmv, regs); } +static void __kprobes +t16_simulate_ldr_literal(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + unsigned long* base = (unsigned long *)(thumb_probe_pc(p) & ~3); + long index = insn & 0xff; + int rt = (insn >> 8) & 0x7; + regs->uregs[rt] = base[index]; +} + +static void __kprobes +t16_simulate_ldrstr_sp_relative(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + unsigned long* base = (unsigned long *)regs->ARM_sp; + long index = insn & 0xff; + int rt = (insn >> 8) & 0x7; + if (insn & 0x800) /* LDR */ + regs->uregs[rt] = base[index]; + else /* STR */ + base[index] = regs->uregs[rt]; +} + static unsigned long __kprobes t16_emulate_loregs(struct kprobe *p, struct pt_regs *regs) { @@ -218,11 +241,48 @@ const union decode_item kprobe_decode_thumb16_table[] = { DECODE_CUSTOM (0xfc00, 0x4400, t16_decode_hiregs), /* + * Load from Literal Pool + * LDR (literal) 0100 1xxx xxxx xxxx + */ + DECODE_SIMULATE (0xf800, 0x4800, t16_simulate_ldr_literal), + + /* + * 16-bit Thumb Load/store instructions + * 0101 xxxx xxxx xxxx + * 011x xxxx xxxx xxxx + * 100x xxxx xxxx xxxx + */ + + /* STR (register) 0101 000x xxxx xxxx */ + /* STRH (register) 0101 001x xxxx xxxx */ + /* STRB (register) 0101 010x xxxx xxxx */ + /* LDRSB (register) 0101 011x xxxx xxxx */ + /* LDR (register) 0101 100x xxxx xxxx */ + /* LDRH (register) 0101 101x xxxx xxxx */ + /* LDRB (register) 0101 110x xxxx xxxx */ + /* LDRSH (register) 0101 111x xxxx xxxx */ + /* STR (immediate, Thumb) 0110 0xxx xxxx xxxx */ + /* LDR (immediate, Thumb) 0110 1xxx xxxx xxxx */ + /* STRB (immediate, Thumb) 0111 0xxx xxxx xxxx */ + /* LDRB (immediate, Thumb) 0111 1xxx xxxx xxxx */ + DECODE_EMULATE (0xc000, 0x4000, t16_emulate_loregs_rwflags), + /* STRH (immediate, Thumb) 1000 0xxx xxxx xxxx */ + /* LDRH (immediate, Thumb) 1000 1xxx xxxx xxxx */ + DECODE_EMULATE (0xf000, 0x8000, t16_emulate_loregs_rwflags), + /* STR (immediate, Thumb) 1001 0xxx xxxx xxxx */ + /* LDR (immediate, Thumb) 1001 1xxx xxxx xxxx */ + DECODE_SIMULATE (0xf000, 0x9000, t16_simulate_ldrstr_sp_relative), + + /* * Miscellaneous 16-bit instructions * 1011 xxxx xxxx xxxx */ DECODE_TABLE (0xf000, 0xb000, t16_table_1011), + /* STM 1100 0xxx xxxx xxxx */ + /* LDM 1100 1xxx xxxx xxxx */ + DECODE_EMULATE (0xf000, 0xc000, t16_emulate_loregs_rwflags), + DECODE_END }; |