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authorWang Nan <wangnan0@huawei.com>2015-01-05 14:29:21 +0300
committerJon Medhurst <tixy@linaro.org>2015-01-13 19:10:06 +0300
commit6624cf651f1a14363d0385f36dc255d304ac7ebb (patch)
tree38cb38d33f5faa96e36814caa3fa63bfe322c193 /arch/arm/probes/kprobes/checkers-arm.c
parent83803d97dae1eaf6850a45ef8ee179cc66e147dc (diff)
downloadlinux-6624cf651f1a14363d0385f36dc255d304ac7ebb.tar.xz
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>
Diffstat (limited to 'arch/arm/probes/kprobes/checkers-arm.c')
-rw-r--r--arch/arm/probes/kprobes/checkers-arm.c99
1 files changed, 99 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 000000000000..f8176631d2a5
--- /dev/null
+++ b/arch/arm/probes/kprobes/checkers-arm.c
@@ -0,0 +1,99 @@
+/*
+ * 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},
+};