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| author | Jon Medhurst | 2011-07-02 17:05:53 +0200 |
|---|---|---|
| committer | Tixy | 2011-07-13 19:32:44 +0200 |
| commit | 2f335829040cb16d0640e87121bef208894d4934 (patch) | |
| tree | d4377f53bbbc4a6983716c305bccee697fa1c269 | |
| parent | ARM: kprobes: Decode 16-bit Thumb load and store instructions (diff) | |
| download | kernel-qcow2-linux-2f335829040cb16d0640e87121bef208894d4934.tar.gz kernel-qcow2-linux-2f335829040cb16d0640e87121bef208894d4934.tar.xz kernel-qcow2-linux-2f335829040cb16d0640e87121bef208894d4934.zip | |
ARM: kprobes: Decode 16-bit Thumb PC- and SP-relative address instructions
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
| -rw-r--r-- | arch/arm/kernel/kprobes-thumb.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/arm/kernel/kprobes-thumb.c b/arch/arm/kernel/kprobes-thumb.c index 632a5e8f5977..2b30828d5f0c 100644 --- a/arch/arm/kernel/kprobes-thumb.c +++ b/arch/arm/kernel/kprobes-thumb.c @@ -74,6 +74,28 @@ t16_simulate_ldrstr_sp_relative(struct kprobe *p, struct pt_regs *regs) base[index] = regs->uregs[rt]; } +static void __kprobes +t16_simulate_reladr(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + unsigned long base = (insn & 0x800) ? regs->ARM_sp + : (thumb_probe_pc(p) & ~3); + long offset = insn & 0xff; + int rt = (insn >> 8) & 0x7; + regs->uregs[rt] = base + offset * 4; +} + +static void __kprobes +t16_simulate_add_sp_imm(struct kprobe *p, struct pt_regs *regs) +{ + kprobe_opcode_t insn = p->opcode; + long imm = insn & 0x7f; + if (insn & 0x80) /* SUB */ + regs->ARM_sp -= imm * 4; + else /* ADD */ + regs->ARM_sp += imm * 4; +} + static unsigned long __kprobes t16_emulate_loregs(struct kprobe *p, struct pt_regs *regs) { @@ -154,6 +176,10 @@ t16_decode_hiregs(kprobe_opcode_t insn, struct arch_specific_insn *asi) static const union decode_item t16_table_1011[] = { /* Miscellaneous 16-bit instructions */ + /* ADD (SP plus immediate) 1011 0000 0xxx xxxx */ + /* SUB (SP minus immediate) 1011 0000 1xxx xxxx */ + DECODE_SIMULATE (0xff00, 0xb000, t16_simulate_add_sp_imm), + /* * If-Then, and hints * 1011 1111 xxxx xxxx @@ -274,6 +300,13 @@ const union decode_item kprobe_decode_thumb16_table[] = { DECODE_SIMULATE (0xf000, 0x9000, t16_simulate_ldrstr_sp_relative), /* + * Generate PC-/SP-relative address + * ADR (literal) 1010 0xxx xxxx xxxx + * ADD (SP plus immediate) 1010 1xxx xxxx xxxx + */ + DECODE_SIMULATE (0xf000, 0xa000, t16_simulate_reladr), + + /* * Miscellaneous 16-bit instructions * 1011 xxxx xxxx xxxx */ |