ARM: kprobes: Decode 16-bit Thumb PC- and SP-relative address instructions (2f335829) · Commits · 戴 / test

arch/arm/kernel/kprobes-thumb.c

+33 −0

Original line number	Diff line number	Diff line
		@@ -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
		@@ -273,6 +299,13 @@ const union decode_item kprobe_decode_thumb16_table[] = {
		/* LDR (immediate, Thumb) 1001 1xxx xxxx xxxx */
		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

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