Initial import

1 files changed, 192 insertions, 0 deletions

diff --git a/arch/arm/probes/kprobes/checkers-arm.c b/arch/arm/probes/kprobes/checkers-arm.c
new file mode 100644
index 000000000..7b9817333
--- /dev/null
+++ b/arch/arm/probes/kprobes/checkers-arm.c
@@ -0,0 +1,192 @@
+/*
+ * arch/arm/probes/kprobes/checkers-arm.c
+ *
+ * Copyright (C) 2014 Huawei 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include "../decode.h"
+#include "../decode-arm.h"
+#include "checkers.h"
+
+static enum probes_insn __kprobes arm_check_stack(probes_opcode_t insn,
+		struct arch_probes_insn *asi,
+		const struct decode_header *h)
+{
+	/*
+	 * PROBES_LDRSTRD, PROBES_LDMSTM, PROBES_STORE,
+	 * PROBES_STORE_EXTRA may get here. Simply mark all normal
+	 * insns as STACK_USE_NONE.
+	 */
+	static const union decode_item table[] = {
+		/*
+		 * 'STR{,D,B,H}, Rt, [Rn, Rm]' should be marked as UNKNOWN
+		 * if Rn or Rm is SP.
+		 *                                 x
+		 * STR (register)	cccc 011x x0x0 xxxx xxxx xxxx xxxx xxxx
+		 * STRB (register)	cccc 011x x1x0 xxxx xxxx xxxx xxxx xxxx
+		 */
+		DECODE_OR	(0x0e10000f, 0x0600000d),
+		DECODE_OR	(0x0e1f0000, 0x060d0000),
+
+		/*
+		 *                                                     x
+		 * STRD (register)	cccc 000x x0x0 xxxx xxxx xxxx 1111 xxxx
+		 * STRH (register)	cccc 000x x0x0 xxxx xxxx xxxx 1011 xxxx
+		 */
+		DECODE_OR	(0x0e5000bf, 0x000000bd),
+		DECODE_CUSTOM	(0x0e5f00b0, 0x000d00b0, STACK_USE_UNKNOWN),
+
+		/*
+		 * For PROBES_LDMSTM, only stmdx sp, [...] need to examine
+		 *
+		 * Bit B/A (bit 24) encodes arithmetic operation order. 1 means
+		 * before, 0 means after.
+		 * Bit I/D (bit 23) encodes arithmetic operation. 1 means
+		 * increment, 0 means decrement.
+		 *
+		 * So:
+		 *                              B I
+		 *                              / /
+		 *                              A D   | Rn |
+		 * STMDX SP, [...]	cccc 100x 00x0 xxxx xxxx xxxx xxxx xxxx
+		 */
+		DECODE_CUSTOM	(0x0edf0000, 0x080d0000, STACK_USE_STMDX),
+
+		/*                              P U W | Rn | Rt |     imm12    |*/
+		/* STR (immediate)	cccc 010x x0x0 1101 xxxx xxxx xxxx xxxx */
+		/* STRB (immediate)	cccc 010x x1x0 1101 xxxx xxxx xxxx xxxx */
+		/*                              P U W | Rn | Rt |imm4|    |imm4|*/
+		/* STRD (immediate)	cccc 000x x1x0 1101 xxxx xxxx 1111 xxxx */
+		/* STRH (immediate)	cccc 000x x1x0 1101 xxxx xxxx 1011 xxxx */
+		/*
+		 * index = (P == '1'); add = (U == '1').
+		 * Above insns with:
+		 *    index == 0 (str{,d,h} rx, [sp], #+/-imm) or
+		 *    add == 1 (str{,d,h} rx, [sp, #+<imm>])
+		 * should be STACK_USE_NONE.
+		 * Only str{,b,d,h} rx,[sp,#-n] (P == 1 and U == 0) are
+		 * required to be examined.
+		 */
+		/* STR{,B} Rt,[SP,#-n]	cccc 0101 0xx0 1101 xxxx xxxx xxxx xxxx */
+		DECODE_CUSTOM	(0x0f9f0000, 0x050d0000, STACK_USE_FIXED_XXX),
+
+		/* STR{D,H} Rt,[SP,#-n]	cccc 0001 01x0 1101 xxxx xxxx 1x11 xxxx */
+		DECODE_CUSTOM	(0x0fdf00b0, 0x014d00b0, STACK_USE_FIXED_X0X),
+
+		/* fall through */
+		DECODE_CUSTOM	(0, 0, STACK_USE_NONE),
+		DECODE_END
+	};
+
+	return probes_decode_insn(insn, asi, table, false, false, stack_check_actions, NULL);
+}
+
+const struct decode_checker arm_stack_checker[NUM_PROBES_ARM_ACTIONS] = {
+	[PROBES_LDRSTRD] = {.checker = arm_check_stack},
+	[PROBES_STORE_EXTRA] = {.checker = arm_check_stack},
+	[PROBES_STORE] = {.checker = arm_check_stack},
+	[PROBES_LDMSTM] = {.checker = arm_check_stack},
+};
+
+static enum probes_insn __kprobes arm_check_regs_nouse(probes_opcode_t insn,
+		struct arch_probes_insn *asi,
+		const struct decode_header *h)
+{
+	asi->register_usage_flags = 0;
+	return INSN_GOOD;
+}
+
+static enum probes_insn arm_check_regs_normal(probes_opcode_t insn,
+		struct arch_probes_insn *asi,
+		const struct decode_header *h)
+{
+	u32 regs = h->type_regs.bits >> DECODE_TYPE_BITS;
+	int i;
+
+	asi->register_usage_flags = 0;
+	for (i = 0; i < 5; regs >>= 4, insn >>= 4, i++)
+		if (regs & 0xf)
+			asi->register_usage_flags |= 1 << (insn & 0xf);
+
+	return INSN_GOOD;
+}
+
+
+static enum probes_insn arm_check_regs_ldmstm(probes_opcode_t insn,
+		struct arch_probes_insn *asi,
+		const struct decode_header *h)
+{
+	unsigned int reglist = insn & 0xffff;
+	unsigned int rn = (insn >> 16) & 0xf;
+	asi->register_usage_flags = reglist | (1 << rn);
+	return INSN_GOOD;
+}
+
+static enum probes_insn arm_check_regs_mov_ip_sp(probes_opcode_t insn,
+		struct arch_probes_insn *asi,
+		const struct decode_header *h)
+{
+	/* Instruction is 'mov ip, sp' i.e. 'mov r12, r13' */
+	asi->register_usage_flags = (1 << 12) | (1<< 13);
+	return INSN_GOOD;
+}
+
+/*
+ *                                    | Rn |Rt/d|         | Rm |
+ * LDRD (register)      cccc 000x x0x0 xxxx xxxx xxxx 1101 xxxx
+ * STRD (register)      cccc 000x x0x0 xxxx xxxx xxxx 1111 xxxx
+ *                                    | Rn |Rt/d|         |imm4L|
+ * LDRD (immediate)     cccc 000x x1x0 xxxx xxxx xxxx 1101 xxxx
+ * STRD (immediate)     cccc 000x x1x0 xxxx xxxx xxxx 1111 xxxx
+ *
+ * Such instructions access Rt/d and its next register, so different
+ * from others, a specific checker is required to handle this extra
+ * implicit register usage.
+ */
+static enum probes_insn arm_check_regs_ldrdstrd(probes_opcode_t insn,
+		struct arch_probes_insn *asi,
+		const struct decode_header *h)
+{
+	int rdt = (insn >> 12) & 0xf;
+	arm_check_regs_normal(insn, asi, h);
+	asi->register_usage_flags |= 1 << (rdt + 1);
+	return INSN_GOOD;
+}
+
+
+const struct decode_checker arm_regs_checker[NUM_PROBES_ARM_ACTIONS] = {
+	[PROBES_MRS] = {.checker = arm_check_regs_normal},
+	[PROBES_SATURATING_ARITHMETIC] = {.checker = arm_check_regs_normal},
+	[PROBES_MUL1] = {.checker = arm_check_regs_normal},
+	[PROBES_MUL2] = {.checker = arm_check_regs_normal},
+	[PROBES_MUL_ADD_LONG] = {.checker = arm_check_regs_normal},
+	[PROBES_MUL_ADD] = {.checker = arm_check_regs_normal},
+	[PROBES_LOAD] = {.checker = arm_check_regs_normal},
+	[PROBES_LOAD_EXTRA] = {.checker = arm_check_regs_normal},
+	[PROBES_STORE] = {.checker = arm_check_regs_normal},
+	[PROBES_STORE_EXTRA] = {.checker = arm_check_regs_normal},
+	[PROBES_DATA_PROCESSING_REG] = {.checker = arm_check_regs_normal},
+	[PROBES_DATA_PROCESSING_IMM] = {.checker = arm_check_regs_normal},
+	[PROBES_SEV] = {.checker = arm_check_regs_nouse},
+	[PROBES_WFE] = {.checker = arm_check_regs_nouse},
+	[PROBES_SATURATE] = {.checker = arm_check_regs_normal},
+	[PROBES_REV] = {.checker = arm_check_regs_normal},
+	[PROBES_MMI] = {.checker = arm_check_regs_normal},
+	[PROBES_PACK] = {.checker = arm_check_regs_normal},
+	[PROBES_EXTEND] = {.checker = arm_check_regs_normal},
+	[PROBES_EXTEND_ADD] = {.checker = arm_check_regs_normal},
+	[PROBES_BITFIELD] = {.checker = arm_check_regs_normal},
+	[PROBES_LDMSTM] = {.checker = arm_check_regs_ldmstm},
+	[PROBES_MOV_IP_SP] = {.checker = arm_check_regs_mov_ip_sp},
+	[PROBES_LDRSTRD] = {.checker = arm_check_regs_ldrdstrd},
+};