cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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checkers-common.c (2485B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * arch/arm/probes/kprobes/checkers-common.c
      4 *
      5 * Copyright (C) 2014 Huawei Inc.
      6 */
      7
      8#include <linux/kernel.h>
      9#include "../decode.h"
     10#include "../decode-arm.h"
     11#include "checkers.h"
     12
     13enum probes_insn checker_stack_use_none(probes_opcode_t insn,
     14		struct arch_probes_insn *asi,
     15		const struct decode_header *h)
     16{
     17	asi->stack_space = 0;
     18	return INSN_GOOD_NO_SLOT;
     19}
     20
     21enum probes_insn checker_stack_use_unknown(probes_opcode_t insn,
     22		struct arch_probes_insn *asi,
     23		const struct decode_header *h)
     24{
     25	asi->stack_space = -1;
     26	return INSN_GOOD_NO_SLOT;
     27}
     28
     29#ifdef CONFIG_THUMB2_KERNEL
     30enum probes_insn checker_stack_use_imm_0xx(probes_opcode_t insn,
     31		struct arch_probes_insn *asi,
     32		const struct decode_header *h)
     33{
     34	int imm = insn & 0xff;
     35	asi->stack_space = imm;
     36	return INSN_GOOD_NO_SLOT;
     37}
     38
     39/*
     40 * Different from other insn uses imm8, the real addressing offset of
     41 * STRD in T32 encoding should be imm8 * 4. See ARMARM description.
     42 */
     43enum probes_insn checker_stack_use_t32strd(probes_opcode_t insn,
     44		struct arch_probes_insn *asi,
     45		const struct decode_header *h)
     46{
     47	int imm = insn & 0xff;
     48	asi->stack_space = imm << 2;
     49	return INSN_GOOD_NO_SLOT;
     50}
     51#else
     52enum probes_insn checker_stack_use_imm_x0x(probes_opcode_t insn,
     53		struct arch_probes_insn *asi,
     54		const struct decode_header *h)
     55{
     56	int imm = ((insn & 0xf00) >> 4) + (insn & 0xf);
     57	asi->stack_space = imm;
     58	return INSN_GOOD_NO_SLOT;
     59}
     60#endif
     61
     62enum probes_insn checker_stack_use_imm_xxx(probes_opcode_t insn,
     63		struct arch_probes_insn *asi,
     64		const struct decode_header *h)
     65{
     66	int imm = insn & 0xfff;
     67	asi->stack_space = imm;
     68	return INSN_GOOD_NO_SLOT;
     69}
     70
     71enum probes_insn checker_stack_use_stmdx(probes_opcode_t insn,
     72		struct arch_probes_insn *asi,
     73		const struct decode_header *h)
     74{
     75	unsigned int reglist = insn & 0xffff;
     76	int pbit = insn & (1 << 24);
     77	asi->stack_space = (hweight32(reglist) - (!pbit ? 1 : 0)) * 4;
     78
     79	return INSN_GOOD_NO_SLOT;
     80}
     81
     82const union decode_action stack_check_actions[] = {
     83	[STACK_USE_NONE] = {.decoder = checker_stack_use_none},
     84	[STACK_USE_UNKNOWN] = {.decoder = checker_stack_use_unknown},
     85#ifdef CONFIG_THUMB2_KERNEL
     86	[STACK_USE_FIXED_0XX] = {.decoder = checker_stack_use_imm_0xx},
     87	[STACK_USE_T32STRD] = {.decoder = checker_stack_use_t32strd},
     88#else
     89	[STACK_USE_FIXED_X0X] = {.decoder = checker_stack_use_imm_x0x},
     90#endif
     91	[STACK_USE_FIXED_XXX] = {.decoder = checker_stack_use_imm_xxx},
     92	[STACK_USE_STMDX] = {.decoder = checker_stack_use_stmdx},
     93};