ARM: kprobes: collects stack consumption for store instructions
This patch uses the previously introduced checker functionality on
store instructions to record their stack consumption information to
arch_probes_insn.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Reviewed-by: Jon Medhurst <tixy@linaro.org>
Signed-off-by: Jon Medhurst <tixy@linaro.org>
diff --git a/arch/arm/probes/kprobes/checkers-common.c b/arch/arm/probes/kprobes/checkers-common.c
new file mode 100644
index 0000000..971119c
--- /dev/null
+++ b/arch/arm/probes/kprobes/checkers-common.c
@@ -0,0 +1,101 @@
+/*
+ * arch/arm/probes/kprobes/checkers-common.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"
+
+enum probes_insn checker_stack_use_none(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *h)
+{
+ asi->stack_space = 0;
+ return INSN_GOOD_NO_SLOT;
+}
+
+enum probes_insn checker_stack_use_unknown(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *h)
+{
+ asi->stack_space = -1;
+ return INSN_GOOD_NO_SLOT;
+}
+
+#ifdef CONFIG_THUMB2_KERNEL
+enum probes_insn checker_stack_use_imm_0xx(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *h)
+{
+ int imm = insn & 0xff;
+ asi->stack_space = imm;
+ return INSN_GOOD_NO_SLOT;
+}
+
+/*
+ * Different from other insn uses imm8, the real addressing offset of
+ * STRD in T32 encoding should be imm8 * 4. See ARMARM description.
+ */
+enum probes_insn checker_stack_use_t32strd(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *h)
+{
+ int imm = insn & 0xff;
+ asi->stack_space = imm << 2;
+ return INSN_GOOD_NO_SLOT;
+}
+#else
+enum probes_insn checker_stack_use_imm_x0x(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *h)
+{
+ int imm = ((insn & 0xf00) >> 4) + (insn & 0xf);
+ asi->stack_space = imm;
+ return INSN_GOOD_NO_SLOT;
+}
+#endif
+
+enum probes_insn checker_stack_use_imm_xxx(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *h)
+{
+ int imm = insn & 0xfff;
+ asi->stack_space = imm;
+ return INSN_GOOD_NO_SLOT;
+}
+
+enum probes_insn checker_stack_use_stmdx(probes_opcode_t insn,
+ struct arch_probes_insn *asi,
+ const struct decode_header *h)
+{
+ unsigned int reglist = insn & 0xffff;
+ int pbit = insn & (1 << 24);
+ asi->stack_space = (hweight32(reglist) - (!pbit ? 1 : 0)) * 4;
+
+ return INSN_GOOD_NO_SLOT;
+}
+
+const union decode_action stack_check_actions[] = {
+ [STACK_USE_NONE] = {.decoder = checker_stack_use_none},
+ [STACK_USE_UNKNOWN] = {.decoder = checker_stack_use_unknown},
+#ifdef CONFIG_THUMB2_KERNEL
+ [STACK_USE_FIXED_0XX] = {.decoder = checker_stack_use_imm_0xx},
+ [STACK_USE_T32STRD] = {.decoder = checker_stack_use_t32strd},
+#else
+ [STACK_USE_FIXED_X0X] = {.decoder = checker_stack_use_imm_x0x},
+#endif
+ [STACK_USE_FIXED_XXX] = {.decoder = checker_stack_use_imm_xxx},
+ [STACK_USE_STMDX] = {.decoder = checker_stack_use_stmdx},
+};