Initial import

1 files changed, 171 insertions, 0 deletions

diff --git a/arch/arm/probes/kprobes/actions-common.c b/arch/arm/probes/kprobes/actions-common.c
new file mode 100644
index 000000000..bd20a71cd
--- /dev/null
+++ b/arch/arm/probes/kprobes/actions-common.c
@@ -0,0 +1,171 @@
+/*
+ * arch/arm/probes/kprobes/actions-common.c
+ *
+ * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
+ *
+ * Some contents moved here from arch/arm/include/asm/kprobes-arm.c which is
+ * Copyright (C) 2006, 2007 Motorola Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <asm/opcodes.h>
+
+#include "core.h"
+
+
+static void __kprobes simulate_ldm1stm1(probes_opcode_t insn,
+		struct arch_probes_insn *asi,
+		struct pt_regs *regs)
+{
+	int rn = (insn >> 16) & 0xf;
+	int lbit = insn & (1 << 20);
+	int wbit = insn & (1 << 21);
+	int ubit = insn & (1 << 23);
+	int pbit = insn & (1 << 24);
+	long *addr = (long *)regs->uregs[rn];
+	int reg_bit_vector;
+	int reg_count;
+
+	reg_count = 0;
+	reg_bit_vector = insn & 0xffff;
+	while (reg_bit_vector) {
+		reg_bit_vector &= (reg_bit_vector - 1);
+		++reg_count;
+	}
+
+	if (!ubit)
+		addr -= reg_count;
+	addr += (!pbit == !ubit);
+
+	reg_bit_vector = insn & 0xffff;
+	while (reg_bit_vector) {
+		int reg = __ffs(reg_bit_vector);
+		reg_bit_vector &= (reg_bit_vector - 1);
+		if (lbit)
+			regs->uregs[reg] = *addr++;
+		else
+			*addr++ = regs->uregs[reg];
+	}
+
+	if (wbit) {
+		if (!ubit)
+			addr -= reg_count;
+		addr -= (!pbit == !ubit);
+		regs->uregs[rn] = (long)addr;
+	}
+}
+
+static void __kprobes simulate_stm1_pc(probes_opcode_t insn,
+	struct arch_probes_insn *asi,
+	struct pt_regs *regs)
+{
+	unsigned long addr = regs->ARM_pc - 4;
+
+	regs->ARM_pc = (long)addr + str_pc_offset;
+	simulate_ldm1stm1(insn, asi, regs);
+	regs->ARM_pc = (long)addr + 4;
+}
+
+static void __kprobes simulate_ldm1_pc(probes_opcode_t insn,
+	struct arch_probes_insn *asi,
+	struct pt_regs *regs)
+{
+	simulate_ldm1stm1(insn, asi, regs);
+	load_write_pc(regs->ARM_pc, regs);
+}
+
+static void __kprobes
+emulate_generic_r0_12_noflags(probes_opcode_t insn,
+	struct arch_probes_insn *asi, struct pt_regs *regs)
+{
+	register void *rregs asm("r1") = regs;
+	register void *rfn asm("lr") = asi->insn_fn;
+
+	__asm__ __volatile__ (
+		"stmdb	sp!, {%[regs], r11}	\n\t"
+		"ldmia	%[regs], {r0-r12}	\n\t"
+#if __LINUX_ARM_ARCH__ >= 6
+		"blx	%[fn]			\n\t"
+#else
+		"str	%[fn], [sp, #-4]!	\n\t"
+		"adr	lr, 1f			\n\t"
+		"ldr	pc, [sp], #4		\n\t"
+		"1:				\n\t"
+#endif
+		"ldr	lr, [sp], #4		\n\t" /* lr = regs */
+		"stmia	lr, {r0-r12}		\n\t"
+		"ldr	r11, [sp], #4		\n\t"
+		: [regs] "=r" (rregs), [fn] "=r" (rfn)
+		: "0" (rregs), "1" (rfn)
+		: "r0", "r2", "r3", "r4", "r5", "r6", "r7",
+		  "r8", "r9", "r10", "r12", "memory", "cc"
+		);
+}
+
+static void __kprobes
+emulate_generic_r2_14_noflags(probes_opcode_t insn,
+	struct arch_probes_insn *asi, struct pt_regs *regs)
+{
+	emulate_generic_r0_12_noflags(insn, asi,
+		(struct pt_regs *)(regs->uregs+2));
+}
+
+static void __kprobes
+emulate_ldm_r3_15(probes_opcode_t insn,
+	struct arch_probes_insn *asi, struct pt_regs *regs)
+{
+	emulate_generic_r0_12_noflags(insn, asi,
+		(struct pt_regs *)(regs->uregs+3));
+	load_write_pc(regs->ARM_pc, regs);
+}
+
+enum probes_insn __kprobes
+kprobe_decode_ldmstm(probes_opcode_t insn, struct arch_probes_insn *asi,
+		const struct decode_header *h)
+{
+	probes_insn_handler_t *handler = 0;
+	unsigned reglist = insn & 0xffff;
+	int is_ldm = insn & 0x100000;
+	int rn = (insn >> 16) & 0xf;
+
+	if (rn <= 12 && (reglist & 0xe000) == 0) {
+		/* Instruction only uses registers in the range R0..R12 */
+		handler = emulate_generic_r0_12_noflags;
+
+	} else if (rn >= 2 && (reglist & 0x8003) == 0) {
+		/* Instruction only uses registers in the range R2..R14 */
+		rn -= 2;
+		reglist >>= 2;
+		handler = emulate_generic_r2_14_noflags;
+
+	} else if (rn >= 3 && (reglist & 0x0007) == 0) {
+		/* Instruction only uses registers in the range R3..R15 */
+		if (is_ldm && (reglist & 0x8000)) {
+			rn -= 3;
+			reglist >>= 3;
+			handler = emulate_ldm_r3_15;
+		}
+	}
+
+	if (handler) {
+		/* We can emulate the instruction in (possibly) modified form */
+		asi->insn[0] = __opcode_to_mem_arm((insn & 0xfff00000) |
+						   (rn << 16) | reglist);
+		asi->insn_handler = handler;
+		return INSN_GOOD;
+	}
+
+	/* Fallback to slower simulation... */
+	if (reglist & 0x8000)
+		handler = is_ldm ? simulate_ldm1_pc : simulate_stm1_pc;
+	else
+		handler = simulate_ldm1stm1;
+	asi->insn_handler = handler;
+	return INSN_GOOD_NO_SLOT;
+}
+