decode-arm.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
*
* arch/arm/probes/decode-arm.c
*
* Some code moved here from arch/arm/kernel/kprobes-arm.c
*
* Copyright (C) 2006, 2007 Motorola Inc.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/stddef.h>
#include <linux/ptrace.h>
#include "decode.h"
#include "decode-arm.h"
#define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit)))))
#define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25)
/*
* To avoid the complications of mimicing single-stepping on a
* processor without a Next-PC or a single-step mode, and to
* avoid having to deal with the side-effects of boosting, we
* simulate or emulate (almost) all ARM instructions.
*
* "Simulation" is where the instruction's behavior is duplicated in
* C code. "Emulation" is where the original instruction is rewritten
* and executed, often by altering its registers.
*
* By having all behavior of the kprobe'd instruction completed before
* returning from the kprobe_handler(), all locks (scheduler and
* interrupt) can safely be released. There is no need for secondary
* breakpoints, no race with MP or preemptable kernels, nor having to
* clean up resources counts at a later time impacting overall system
* performance. By rewriting the instruction, only the minimum registers
* need to be loaded and saved back optimizing performance.
*
* Calling the insnslot_*_rwflags version of a function doesn't hurt
* anything even when the CPSR flags aren't updated by the
* instruction. It's just a little slower in return for saving
* a little space by not having a duplicate function that doesn't
* update the flags. (The same optimization can be said for
* instructions that do or don't perform register writeback)
* Also, instructions can either read the flags, only write the
* flags, or read and write the flags. To save combinations
* rather than for sheer performance, flag functions just assume
* read and write of flags.
*/
void __kprobes simulate_bbl(probes_opcode_t insn,
struct arch_probes_insn *asi, struct pt_regs *regs)
{
long iaddr = (long) regs->ARM_pc - 4;
int disp = branch_displacement(insn);
if (insn & (1 << 24))
regs->ARM_lr = iaddr + 4;
regs->ARM_pc = iaddr + 8 + disp;
}
void __kprobes simulate_blx1(probes_opcode_t insn,
struct arch_probes_insn *asi, struct pt_regs *regs)
{
long iaddr = (long) regs->ARM_pc - 4;
int disp = branch_displacement(insn);
regs->ARM_lr = iaddr + 4;
regs->ARM_pc = iaddr + 8 + disp + ((insn >> 23) & 0x2);
regs->ARM_cpsr |= PSR_T_BIT;
}
void __kprobes simulate_blx2bx(probes_opcode_t insn,
struct arch_probes_insn *asi, struct pt_regs *regs)
{
int rm = insn & 0xf;
long rmv = regs->uregs[rm];
if (insn & (1 << 5))
regs->ARM_lr = (long) regs->ARM_pc;
regs->ARM_pc = rmv & ~0x1;
regs->ARM_cpsr &= ~PSR_T_BIT;
if (rmv & 0x1)
regs->ARM_cpsr |= PSR_T_BIT;
}
void __kprobes simulate_mrs(probes_opcode_t insn,
struct arch_probes_insn *asi, struct pt_regs *regs)
{
int rd = (insn >> 12) & 0xf;
unsigned long mask = 0xf8ff03df; /* Mask out execution state */
regs->uregs[rd] = regs->ARM_cpsr & mask;
}
void __kprobes simulate_mov_ipsp(probes_opcode_t insn,
struct arch_probes_insn *asi, struct pt_regs *regs)
{
regs->uregs[12] = regs->uregs[13];
}
/*
* For the instruction masking and comparisons in all the "space_*"
* functions below, Do _not_ rearrange the order of tests unless
* you're very, very sure of what you are doing. For the sake of
* efficiency, the masks for some tests sometimes assume other test
* have been done prior to them so the number of patterns to test
* for an instruction set can be as broad as possible to reduce the
* number of tests needed.
*/
static const union decode_item arm_1111_table[] = {
/* Unconditional instructions */
/* memory hint 1111 0100 x001 xxxx xxxx xxxx xxxx xxxx */
/* PLDI (immediate) 1111 0100 x101 xxxx xxxx xxxx xxxx xxxx */
/* PLDW (immediate) 1111 0101 x001 xxxx xxxx xxxx xxxx xxxx */
/* PLD (immediate) 1111 0101 x101 xxxx xxxx xxxx xxxx xxxx */
DECODE_SIMULATE (0xfe300000, 0xf4100000, PROBES_PRELOAD_IMM),
/* memory hint 1111 0110 x001 xxxx xxxx xxxx xxx0 xxxx */
/* PLDI (register) 1111 0110 x101 xxxx xxxx xxxx xxx0 xxxx */
/* PLDW (register) 1111 0111 x001 xxxx xxxx xxxx xxx0 xxxx */
/* PLD (register) 1111 0111 x101 xxxx xxxx xxxx xxx0 xxxx */
DECODE_SIMULATE (0xfe300010, 0xf6100000, PROBES_PRELOAD_REG),
/* BLX (immediate) 1111 101x xxxx xxxx xxxx xxxx xxxx xxxx */
DECODE_SIMULATE (0xfe000000, 0xfa000000, PROBES_BRANCH_IMM),
/* CPS 1111 0001 0000 xxx0 xxxx xxxx xx0x xxxx */
/* SETEND 1111 0001 0000 0001 xxxx xxxx 0000 xxxx */
/* SRS 1111 100x x1x0 xxxx xxxx xxxx xxxx xxxx */
/* RFE 1111 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
/* Coprocessor instructions... */
/* MCRR2 1111 1100 0100 xxxx xxxx xxxx xxxx xxxx */
/* MRRC2 1111 1100 0101 xxxx xxxx xxxx xxxx xxxx */
/* LDC2 1111 110x xxx1 xxxx xxxx xxxx xxxx xxxx */
/* STC2 1111 110x xxx0 xxxx xxxx xxxx xxxx xxxx */
/* CDP2 1111 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */
/* MCR2 1111 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */
/* MRC2 1111 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */
/* Other unallocated instructions... */
DECODE_END
};
static const union decode_item arm_cccc_0001_0xx0____0xxx_table[] = {
/* Miscellaneous instructions */
/* MRS cpsr cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */
DECODE_SIMULATEX(0x0ff000f0, 0x01000000, PROBES_MRS,
REGS(0, NOPC, 0, 0, 0)),
/* BX cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */
DECODE_SIMULATE (0x0ff000f0, 0x01200010, PROBES_BRANCH_REG),
/* BLX (register) cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */
DECODE_SIMULATEX(0x0ff000f0, 0x01200030, PROBES_BRANCH_REG,
REGS(0, 0, 0, 0, NOPC)),
/* CLZ cccc 0001 0110 xxxx xxxx xxxx 0001 xxxx */
DECODE_EMULATEX (0x0ff000f0, 0x01600010, PROBES_CLZ,
REGS(0, NOPC, 0, 0, NOPC)),
/* QADD cccc 0001 0000 xxxx xxxx xxxx 0101 xxxx */
/* QSUB cccc 0001 0010 xxxx xxxx xxxx 0101 xxxx */
/* QDADD cccc 0001 0100 xxxx xxxx xxxx 0101 xxxx */
/* QDSUB cccc 0001 0110 xxxx xxxx xxxx 0101 xxxx */
DECODE_EMULATEX (0x0f9000f0, 0x01000050, PROBES_SATURATING_ARITHMETIC,
REGS(NOPC, NOPC, 0, 0, NOPC)),
/* BXJ cccc 0001 0010 xxxx xxxx xxxx 0010 xxxx */
/* MSR cccc 0001 0x10 xxxx xxxx xxxx 0000 xxxx */
/* MRS spsr cccc 0001 0100 xxxx xxxx xxxx 0000 xxxx */
/* BKPT 1110 0001 0010 xxxx xxxx xxxx 0111 xxxx */
/* SMC cccc 0001 0110 xxxx xxxx xxxx 0111 xxxx */
/* And unallocated instructions... */
DECODE_END
};
static const union decode_item arm_cccc_0001_0xx0____1xx0_table[] = {
/* Halfword multiply and multiply-accumulate */
/* SMLALxy cccc 0001 0100 xxxx xxxx xxxx 1xx0 xxxx */
DECODE_EMULATEX (0x0ff00090, 0x01400080, PROBES_MUL1,
REGS(NOPC, NOPC, NOPC, 0, NOPC)),
/* SMULWy cccc 0001 0010 xxxx xxxx xxxx 1x10 xxxx */
DECODE_OR (0x0ff000b0, 0x012000a0),
/* SMULxy cccc 0001 0110 xxxx xxxx xxxx 1xx0 xxxx */
DECODE_EMULATEX (0x0ff00090, 0x01600080, PROBES_MUL2,
REGS(NOPC, 0, NOPC, 0, NOPC)),
/* SMLAxy cccc 0001 0000 xxxx xxxx xxxx 1xx0 xxxx */
DECODE_OR (0x0ff00090, 0x01000080),
/* SMLAWy cccc 0001 0010 xxxx xxxx xxxx 1x00 xxxx */
DECODE_EMULATEX (0x0ff000b0, 0x01200080, PROBES_MUL2,
REGS(NOPC, NOPC, NOPC, 0, NOPC)),
DECODE_END
};
static const union decode_item arm_cccc_0000_____1001_table[] = {
/* Multiply and multiply-accumulate */
/* MUL cccc 0000 0000 xxxx xxxx xxxx 1001 xxxx */
/* MULS cccc 0000 0001 xxxx xxxx xxxx 1001 xxxx */
DECODE_EMULATEX (0x0fe000f0, 0x00000090, PROBES_MUL2,
REGS(NOPC, 0, NOPC, 0, NOPC)),
/* MLA cccc 0000 0010 xxxx xxxx xxxx 1001 xxxx */
/* MLAS cccc 0000 0011 xxxx xxxx xxxx 1001 xxxx */
DECODE_OR (0x0fe000f0, 0x00200090),
/* MLS cccc 0000 0110 xxxx xxxx xxxx 1001 xxxx */
DECODE_EMULATEX (0x0ff000f0, 0x00600090, PROBES_MUL2,
REGS(NOPC, NOPC, NOPC, 0, NOPC)),
/* UMAAL cccc 0000 0100 xxxx xxxx xxxx 1001 xxxx */
DECODE_OR (0x0ff000f0, 0x00400090),
/* UMULL cccc 0000 1000 xxxx xxxx xxxx 1001 xxxx */
/* UMULLS cccc 0000 1001 xxxx xxxx xxxx 1001 xxxx */
/* UMLAL cccc 0000 1010 xxxx xxxx xxxx 1001 xxxx */
/* UMLALS cccc 0000 1011 xxxx xxxx xxxx 1001 xxxx */
/* SMULL cccc 0000 1100 xxxx xxxx xxxx 1001 xxxx */
/* SMULLS cccc 0000 1101 xxxx xxxx xxxx 1001 xxxx */
/* SMLAL cccc 0000 1110 xxxx xxxx xxxx 1001 xxxx */
/* SMLALS cccc 0000 1111 xxxx xxxx xxxx 1001 xxxx */
DECODE_EMULATEX (0x0f8000f0, 0x00800090, PROBES_MUL1,
REGS(NOPC, NOPC, NOPC, 0, NOPC)),
DECODE_END
};
static const union decode_item arm_cccc_0001_____1001_table[] = {
/* Synchronization primitives */
#if __LINUX_ARM_ARCH__ < 6
/* Deprecated on ARMv6 and may be UNDEFINED on v7 */
/* SMP/SWPB cccc 0001 0x00 xxxx xxxx xxxx 1001 xxxx */
DECODE_EMULATEX (0x0fb000f0, 0x01000090, PROBES_SWP,
REGS(NOPC, NOPC, 0, 0, NOPC)),
#endif
/* LDREX/STREX{,D,B,H} cccc 0001 1xxx xxxx xxxx xxxx 1001 xxxx */
/* And unallocated instructions... */
DECODE_END
};
static const union decode_item arm_cccc_000x_____1xx1_table[] = {
/* Extra load/store instructions */
/* STRHT cccc 0000 xx10 xxxx xxxx xxxx 1011 xxxx */
/* ??? cccc 0000 xx10 xxxx xxxx xxxx 11x1 xxxx */
/* LDRHT cccc 0000 xx11 xxxx xxxx xxxx 1011 xxxx */
/* LDRSBT cccc 0000 xx11 xxxx xxxx xxxx 1101 xxxx */
/* LDRSHT cccc 0000 xx11 xxxx xxxx xxxx 1111 xxxx */
DECODE_REJECT (0x0f200090, 0x00200090),
/* LDRD/STRD lr,pc,{... cccc 000x x0x0 xxxx 111x xxxx 1101 xxxx */
DECODE_REJECT (0x0e10e0d0, 0x0000e0d0),
/* LDRD (register) cccc 000x x0x0 xxxx xxxx xxxx 1101 xxxx */
/* STRD (register) cccc 000x x0x0 xxxx xxxx xxxx 1111 xxxx */
DECODE_EMULATEX (0x0e5000d0, 0x000000d0, PROBES_LDRSTRD,
REGS(NOPCWB, NOPCX, 0, 0, NOPC)),
/* LDRD (immediate) cccc 000x x1x0 xxxx xxxx xxxx 1101 xxxx */
/* STRD (immediate) cccc 000x x1x0 xxxx xxxx xxxx 1111 xxxx */
DECODE_EMULATEX (0x0e5000d0, 0x004000d0, PROBES_LDRSTRD,
REGS(NOPCWB, NOPCX, 0, 0, 0)),
/* STRH (register) cccc 000x x0x0 xxxx xxxx xxxx 1011 xxxx */
DECODE_EMULATEX (0x0e5000f0, 0x000000b0, PROBES_STORE_EXTRA,
REGS(NOPCWB, NOPC, 0, 0, NOPC)),
/* LDRH (register) cccc 000x x0x1 xxxx xxxx xxxx 1011 xxxx */
/* LDRSB (register) cccc 000x x0x1 xxxx xxxx xxxx 1101 xxxx */
/* LDRSH (register) cccc 000x x0x1 xxxx xxxx xxxx 1111 xxxx */
DECODE_EMULATEX (0x0e500090, 0x00100090, PROBES_LOAD_EXTRA,
REGS(NOPCWB, NOPC, 0, 0, NOPC)),
/* STRH (immediate) cccc 000x x1x0 xxxx xxxx xxxx 1011 xxxx */
DECODE_EMULATEX (0x0e5000f0, 0x004000b0, PROBES_STORE_EXTRA,
REGS(NOPCWB, NOPC, 0, 0, 0)),
/* LDRH (immediate) cccc 000x x1x1 xxxx xxxx xxxx 1011 xxxx */
/* LDRSB (immediate) cccc 000x x1x1 xxxx xxxx xxxx 1101 xxxx */
/* LDRSH (immediate) cccc 000x x1x1 xxxx xxxx xxxx 1111 xxxx */
DECODE_EMULATEX (0x0e500090, 0x00500090, PROBES_LOAD_EXTRA,
REGS(NOPCWB, NOPC, 0, 0, 0)),
DECODE_END
};
static const union decode_item arm_cccc_000x_table[] = {
/* Data-processing (register) */
/* <op>S PC, ... cccc 000x xxx1 xxxx 1111 xxxx xxxx xxxx */
DECODE_REJECT (0x0e10f000, 0x0010f000),
/* MOV IP, SP 1110 0001 1010 0000 1100 0000 0000 1101 */
DECODE_SIMULATE (0xffffffff, 0xe1a0c00d, PROBES_MOV_IP_SP),
/* TST (register) cccc 0001 0001 xxxx xxxx xxxx xxx0 xxxx */
/* TEQ (register) cccc 0001 0011 xxxx xxxx xxxx xxx0 xxxx */
/* CMP (register) cccc 0001 0101 xxxx xxxx xxxx xxx0 xxxx */
/* CMN (register) cccc 0001 0111 xxxx xxxx xxxx xxx0 xxxx */
DECODE_EMULATEX (0x0f900010, 0x01100000, PROBES_DATA_PROCESSING_REG,
REGS(ANY, 0, 0, 0, ANY)),
/* MOV (register) cccc 0001 101x xxxx xxxx xxxx xxx0 xxxx */
/* MVN (register) cccc 0001 111x xxxx xxxx xxxx xxx0 xxxx */
DECODE_EMULATEX (0x0fa00010, 0x01a00000, PROBES_DATA_PROCESSING_REG,
REGS(0, ANY, 0, 0, ANY)),
/* AND (register) cccc 0000 000x xxxx xxxx xxxx xxx0 xxxx */
/* EOR (register) cccc 0000 001x xxxx xxxx xxxx xxx0 xxxx */
/* SUB (register) cccc 0000 010x xxxx xxxx xxxx xxx0 xxxx */
/* RSB (register) cccc 0000 011x xxxx xxxx xxxx xxx0 xxxx */
/* ADD (register) cccc 0000 100x xxxx xxxx xxxx xxx0 xxxx */
/* ADC (register) cccc 0000 101x xxxx xxxx xxxx xxx0 xxxx */
/* SBC (register) cccc 0000 110x xxxx xxxx xxxx xxx0 xxxx */
/* RSC (register) cccc 0000 111x xxxx xxxx xxxx xxx0 xxxx */
/* ORR (register) cccc 0001 100x xxxx xxxx xxxx xxx0 xxxx */
/* BIC (register) cccc 0001 110x xxxx xxxx xxxx xxx0 xxxx */
DECODE_EMULATEX (0x0e000010, 0x00000000, PROBES_DATA_PROCESSING_REG,
REGS(ANY, ANY, 0, 0, ANY)),
/* TST (reg-shift reg) cccc 0001 0001 xxxx xxxx xxxx 0xx1 xxxx */
/* TEQ (reg-shift reg) cccc 0001 0011 xxxx xxxx xxxx 0xx1 xxxx */
/* CMP (reg-shift reg) cccc 0001 0101 xxxx xxxx xxxx 0xx1 xxxx */
/* CMN (reg-shift reg) cccc 0001 0111 xxxx xxxx xxxx 0xx1 xxxx */
DECODE_EMULATEX (0x0f900090, 0x01100010, PROBES_DATA_PROCESSING_REG,
REGS(NOPC, 0, NOPC, 0, NOPC)),
/* MOV (reg-shift reg) cccc 0001 101x xxxx xxxx xxxx 0xx1 xxxx */
/* MVN (reg-shift reg) cccc 0001 111x xxxx xxxx xxxx 0xx1 xxxx */
DECODE_EMULATEX (0x0fa00090, 0x01a00010, PROBES_DATA_PROCESSING_REG,
REGS(0, NOPC, NOPC, 0, NOPC)),
/* AND (reg-shift reg) cccc 0000 000x xxxx xxxx xxxx 0xx1 xxxx */
/* EOR (reg-shift reg) cccc 0000 001x xxxx xxxx xxxx 0xx1 xxxx */
/* SUB (reg-shift reg) cccc 0000 010x xxxx xxxx xxxx 0xx1 xxxx */
/* RSB (reg-shift reg) cccc 0000 011x xxxx xxxx xxxx 0xx1 xxxx */
/* ADD (reg-shift reg) cccc 0000 100x xxxx xxxx xxxx 0xx1 xxxx */
/* ADC (reg-shift reg) cccc 0000 101x xxxx xxxx xxxx 0xx1 xxxx */
/* SBC (reg-shift reg) cccc 0000 110x xxxx xxxx xxxx 0xx1 xxxx */
/* RSC (reg-shift reg) cccc 0000 111x xxxx xxxx xxxx 0xx1 xxxx */
/* ORR (reg-shift reg) cccc 0001 100x xxxx xxxx xxxx 0xx1 xxxx */
/* BIC (reg-shift reg) cccc 0001 110x xxxx xxxx xxxx 0xx1 xxxx */
DECODE_EMULATEX (0x0e000090, 0x00000010, PROBES_DATA_PROCESSING_REG,
REGS(NOPC, NOPC, NOPC, 0, NOPC)),
DECODE_END
};
static const union decode_item arm_cccc_001x_table[] = {
/* Data-processing (immediate) */
/* MOVW cccc 0011 0000 xxxx xxxx xxxx xxxx xxxx */
/* MOVT cccc 0011 0100 xxxx xxxx xxxx xxxx xxxx */
DECODE_EMULATEX (0x0fb00000, 0x03000000, PROBES_MOV_HALFWORD,
REGS(0, NOPC, 0, 0, 0)),
/* YIELD cccc 0011 0010 0000 xxxx xxxx 0000 0001 */
DECODE_OR (0x0fff00ff, 0x03200001),
/* SEV cccc 0011 0010 0000 xxxx xxxx 0000 0100 */
DECODE_EMULATE (0x0fff00ff, 0x03200004, PROBES_SEV),
/* NOP cccc 0011 0010 0000 xxxx xxxx 0000 0000 */
/* WFE cccc 0011 0010 0000 xxxx xxxx 0000 0010 */
/* WFI cccc 0011 0010 0000 xxxx xxxx 0000 0011 */
DECODE_SIMULATE (0x0fff00fc, 0x03200000, PROBES_WFE),
/* DBG cccc 0011 0010 0000 xxxx xxxx ffff xxxx */
/* unallocated hints cccc 0011 0010 0000 xxxx xxxx xxxx xxxx */
/* MSR (immediate) cccc 0011 0x10 xxxx xxxx xxxx xxxx xxxx */
DECODE_REJECT (0x0fb00000, 0x03200000),
/* <op>S PC, ... cccc 001x xxx1 xxxx 1111 xxxx xxxx xxxx */
DECODE_REJECT (0x0e10f000, 0x0210f000),
/* TST (immediate) cccc 0011 0001 xxxx xxxx xxxx xxxx xxxx */
/* TEQ (immediate) cccc 0011 0011 xxxx xxxx xxxx xxxx xxxx */
/* CMP (immediate) cccc 0011 0101 xxxx xxxx xxxx xxxx xxxx */
/* CMN (immediate) cccc 0011 0111 xxxx xxxx xxxx xxxx xxxx */
DECODE_EMULATEX (0x0f900000, 0x03100000, PROBES_DATA_PROCESSING_IMM,
REGS(ANY, 0, 0, 0, 0)),
/* MOV (immediate) cccc 0011 101x xxxx xxxx xxxx xxxx xxxx */
/* MVN (immediate) cccc 0011 111x xxxx xxxx xxxx xxxx xxxx */
DECODE_EMULATEX (0x0fa00000, 0x03a00000, PROBES_DATA_PROCESSING_IMM,
REGS(0, ANY, 0, 0, 0)),
/* AND (immediate) cccc 0010 000x xxxx xxxx xxxx xxxx xxxx */
/* EOR (immediate) cccc 0010 001x xxxx xxxx xxxx xxxx xxxx */
/* SUB (immediate) cccc 0010 010x xxxx xxxx xxxx xxxx xxxx */
/* RSB (immediate) cccc 0010 011x xxxx xxxx xxxx xxxx xxxx */
/* ADD (immediate) cccc 0010 100x xxxx xxxx xxxx xxxx xxxx */
/* ADC (immediate) cccc 0010 101x xxxx xxxx xxxx xxxx xxxx */
/* SBC (immediate) cccc 0010 110x xxxx xxxx xxxx xxxx xxxx */
/* RSC (immediate) cccc 0010 111x xxxx xxxx xxxx xxxx xxxx */
/* ORR (immediate) cccc 0011 100x xxxx xxxx xxxx xxxx xxxx */
/* BIC (immediate) cccc 0011 110x xxxx xxxx xxxx xxxx xxxx */
DECODE_EMULATEX (0x0e000000, 0x02000000, PROBES_DATA_PROCESSING_IMM,
REGS(ANY, ANY, 0, 0, 0)),
DECODE_END
};
static const union decode_item arm_cccc_0110_____xxx1_table[] = {
/* Media instructions */
/* SEL cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx */
DECODE_EMULATEX (0x0ff000f0, 0x068000b0, PROBES_SATURATE,
REGS(NOPC, NOPC, 0, 0, NOPC)),
/* SSAT cccc 0110 101x xxxx xxxx xxxx xx01 xxxx */
/* USAT cccc 0110 111x xxxx xxxx xxxx xx01 xxxx */
DECODE_OR(0x0fa00030, 0x06a00010),
/* SSAT16 cccc 0110 1010 xxxx xxxx xxxx 0011 xxxx */
/* USAT16 cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx */
DECODE_EMULATEX (0x0fb000f0, 0x06a00030, PROBES_SATURATE,
REGS(0, NOPC, 0, 0, NOPC)),
/* REV cccc 0110 1011 xxxx xxxx xxxx 0011 xxxx */
/* REV16 cccc 0110 1011 xxxx xxxx xxxx 1011 xxxx */
/* RBIT cccc 0110 1111 xxxx xxxx xxxx 0011 xxxx */
/* REVSH cccc 0110 1111 xxxx xxxx xxxx 1011 xxxx */
DECODE_EMULATEX (0x0fb00070, 0x06b00030, PROBES_REV,
REGS(0, NOPC, 0, 0, NOPC)),
/* ??? cccc 0110 0x00 xxxx xxxx xxxx xxx1 xxxx */
DECODE_REJECT (0x0fb00010, 0x06000010),
/* ??? cccc 0110 0xxx xxxx xxxx xxxx 1011 xxxx */
DECODE_REJECT (0x0f8000f0, 0x060000b0),
/* ??? cccc 0110 0xxx xxxx xxxx xxxx 1101 xxxx */
DECODE_REJECT (0x0f8000f0, 0x060000d0),
/* SADD16 cccc 0110 0001 xxxx xxxx xxxx 0001 xxxx */
/* SADDSUBX cccc 0110 0001 xxxx xxxx xxxx 0011 xxxx */
/* SSUBADDX cccc 0110 0001 xxxx xxxx xxxx 0101 xxxx */
/* SSUB16 cccc 0110 0001 xxxx xxxx xxxx 0111 xxxx */
/* SADD8 cccc 0110 0001 xxxx xxxx xxxx 1001 xxxx */
/* SSUB8 cccc 0110 0001 xxxx xxxx xxxx 1111 xxxx */
/* QADD16 cccc 0110 0010 xxxx xxxx xxxx 0001 xxxx */
/* QADDSUBX cccc 0110 0010 xxxx xxxx xxxx 0011 xxxx */
/* QSUBADDX cccc 0110 0010 xxxx xxxx xxxx 0101 xxxx */
/* QSUB16 cccc 0110 0010 xxxx xxxx xxxx 0111 xxxx */
/* QADD8 cccc 0110 0010 xxxx xxxx xxxx 1001 xxxx */
/* QSUB8 cccc 0110 0010 xxxx xxxx xxxx 1111 xxxx */
/* SHADD16 cccc 0110 0011 xxxx xxxx xxxx 0001 xxxx */
/* SHADDSUBX cccc 0110 0011 xxxx xxxx xxxx 0011 xxxx */
/* SHSUBADDX cccc 0110 0011 xxxx xxxx xxxx 0101 xxxx */
/* SHSUB16 cccc 0110 0011 xxxx xxxx xxxx 0111 xxxx */
/* SHADD8 cccc 0110 0011 xxxx xxxx xxxx 1001 xxxx */
/* SHSUB8 cccc 0110 0011 xxxx xxxx xxxx 1111 xxxx */
/* UADD16 cccc 0110 0101 xxxx xxxx xxxx 0001 xxxx */
/* UADDSUBX cccc 0110 0101 xxxx xxxx xxxx 0011 xxxx */
/* USUBADDX cccc 0110 0101 xxxx xxxx xxxx 0101 xxxx */
/* USUB16 cccc 0110 0101 xxxx xxxx xxxx 0111 xxxx */
/* UADD8 cccc 0110 0101 xxxx xxxx xxxx 1001 xxxx */
/* USUB8 cccc 0110 0101 xxxx xxxx xxxx 1111 xxxx */
/* UQADD16 cccc 0110 0110 xxxx xxxx xxxx 0001 xxxx */
/* UQADDSUBX cccc 0110 0110 xxxx xxxx xxxx 0011 xxxx */
/* UQSUBADDX cccc 0110 0110 xxxx xxxx xxxx 0101 xxxx */
/* UQSUB16 cccc 0110 0110 xxxx xxxx xxxx 0111 xxxx */
/* UQADD8 cccc 0110 0110 xxxx xxxx xxxx 1001 xxxx */
/* UQSUB8 cccc 0110 0110 xxxx xxxx xxxx 1111 xxxx */
/* UHADD16 cccc 0110 0111 xxxx xxxx xxxx 0001 xxxx */
/* UHADDSUBX cccc 0110 0111 xxxx xxxx xxxx 0011 xxxx */
/* UHSUBADDX cccc 0110 0111 xxxx xxxx xxxx 0101 xxxx */
/* UHSUB16 cccc 0110 0111 xxxx xxxx xxxx 0111 xxxx */
/* UHADD8 cccc 0110 0111 xxxx xxxx xxxx 1001 xxxx */
/* UHSUB8 cccc 0110 0111 xxxx xxxx xxxx 1111 xxxx */
DECODE_EMULATEX (0x0f800010, 0x06000010, PROBES_MMI,
REGS(NOPC, NOPC, 0, 0, NOPC)),
/* PKHBT cccc 0110 1000 xxxx xxxx xxxx x001 xxxx */
/* PKHTB cccc 0110 1000 xxxx xxxx xxxx x101 xxxx */
DECODE_EMULATEX (0x0ff00030, 0x06800010, PROBES_PACK,
REGS(NOPC, NOPC, 0, 0, NOPC)),
/* ??? cccc 0110 1001 xxxx xxxx xxxx 0111 xxxx */
/* ??? cccc 0110 1101 xxxx xxxx xxxx 0111 xxxx */
DECODE_REJECT (0x0fb000f0, 0x06900070),
/* SXTB16 cccc 0110 1000 1111 xxxx xxxx 0111 xxxx */
/* SXTB cccc 0110 1010 1111 xxxx xxxx 0111 xxxx */
/* SXTH cccc 0110 1011 1111 xxxx xxxx 0111 xxxx */
/* UXTB16 cccc 0110 1100 1111 xxxx xxxx 0111 xxxx */
/* UXTB cccc 0110 1110 1111 xxxx xxxx 0111 xxxx */
/* UXTH cccc 0110 1111 1111 xxxx xxxx 0111 xxxx */
DECODE_EMULATEX (0x0f8f00f0, 0x068f0070, PROBES_EXTEND,
REGS(0, NOPC, 0, 0, NOPC)),
/* SXTAB16 cccc 0110 1000 xxxx xxxx xxxx 0111 xxxx */
/* SXTAB cccc 0110 1010 xxxx xxxx xxxx 0111 xxxx */
/* SXTAH cccc 0110 1011 xxxx xxxx xxxx 0111 xxxx */
/* UXTAB16 cccc 0110 1100 xxxx xxxx xxxx 0111 xxxx */
/* UXTAB cccc 0110 1110 xxxx xxxx xxxx 0111 xxxx */
/* UXTAH cccc 0110 1111 xxxx xxxx xxxx 0111 xxxx */
DECODE_EMULATEX (0x0f8000f0, 0x06800070, PROBES_EXTEND_ADD,
REGS(NOPCX, NOPC, 0, 0, NOPC)),
DECODE_END
};
static const union decode_item arm_cccc_0111_____xxx1_table[] = {
/* Media instructions */
/* UNDEFINED cccc 0111 1111 xxxx xxxx xxxx 1111 xxxx */
DECODE_REJECT (0x0ff000f0, 0x07f000f0),
/* SMLALD cccc 0111 0100 xxxx xxxx xxxx 00x1 xxxx */
/* SMLSLD cccc 0111 0100 xxxx xxxx xxxx 01x1 xxxx */
DECODE_EMULATEX (0x0ff00090, 0x07400010, PROBES_MUL_ADD_LONG,
REGS(NOPC, NOPC, NOPC, 0, NOPC)),
/* SMUAD cccc 0111 0000 xxxx 1111 xxxx 00x1 xxxx */
/* SMUSD cccc 0111 0000 xxxx 1111 xxxx 01x1 xxxx */
DECODE_OR (0x0ff0f090, 0x0700f010),
/* SMMUL cccc 0111 0101 xxxx 1111 xxxx 00x1 xxxx */
DECODE_OR (0x0ff0f0d0, 0x0750f010),
/* USAD8 cccc 0111 1000 xxxx 1111 xxxx 0001 xxxx */
DECODE_EMULATEX (0x0ff0f0f0, 0x0780f010, PROBES_MUL_ADD,
REGS(NOPC, 0, NOPC, 0, NOPC)),
/* SMLAD cccc 0111 0000 xxxx xxxx xxxx 00x1 xxxx */
/* SMLSD cccc 0111 0000 xxxx xxxx xxxx 01x1 xxxx */
DECODE_OR (0x0ff00090, 0x07000010),
/* SMMLA cccc 0111 0101 xxxx xxxx xxxx 00x1 xxxx */
DECODE_OR (0x0ff000d0, 0x07500010),
/* USADA8 cccc 0111 1000 xxxx xxxx xxxx 0001 xxxx */
DECODE_EMULATEX (0x0ff000f0, 0x07800010, PROBES_MUL_ADD,
REGS(NOPC, NOPCX, NOPC, 0, NOPC)),
/* SMMLS cccc 0111 0101 xxxx xxxx xxxx 11x1 xxxx */
DECODE_EMULATEX (0x0ff000d0, 0x075000d0, PROBES_MUL_ADD,
REGS(NOPC, NOPC, NOPC, 0, NOPC)),
/* SBFX cccc 0111 101x xxxx xxxx xxxx x101 xxxx */
/* UBFX cccc 0111 111x xxxx xxxx xxxx x101 xxxx */
DECODE_EMULATEX (0x0fa00070, 0x07a00050, PROBES_BITFIELD,
REGS(0, NOPC, 0, 0, NOPC)),
/* BFC cccc 0111 110x xxxx xxxx xxxx x001 1111 */
DECODE_EMULATEX (0x0fe0007f, 0x07c0001f, PROBES_BITFIELD,
REGS(0, NOPC, 0, 0, 0)),
/* BFI cccc 0111 110x xxxx xxxx xxxx x001 xxxx */
DECODE_EMULATEX (0x0fe00070, 0x07c00010, PROBES_BITFIELD,
REGS(0, NOPC, 0, 0, NOPCX)),
DECODE_END
};
static const union decode_item arm_cccc_01xx_table[] = {
/* Load/store word and unsigned byte */
/* LDRB/STRB pc,[...] cccc 01xx x0xx xxxx xxxx xxxx xxxx xxxx */
DECODE_REJECT (0x0c40f000, 0x0440f000),
/* STRT cccc 01x0 x010 xxxx xxxx xxxx xxxx xxxx */
/* LDRT cccc 01x0 x011 xxxx xxxx xxxx xxxx xxxx */
/* STRBT cccc 01x0 x110 xxxx xxxx xxxx xxxx xxxx */
/* LDRBT cccc 01x0 x111 xxxx xxxx xxxx xxxx xxxx */
DECODE_REJECT (0x0d200000, 0x04200000),
/* STR (immediate) cccc 010x x0x0 xxxx xxxx xxxx xxxx xxxx */
/* STRB (immediate) cccc 010x x1x0 xxxx xxxx xxxx xxxx xxxx */
DECODE_EMULATEX (0x0e100000, 0x04000000, PROBES_STORE,
REGS(NOPCWB, ANY, 0, 0, 0)),
/* LDR (immediate) cccc 010x x0x1 xxxx xxxx xxxx xxxx xxxx */
/* LDRB (immediate) cccc 010x x1x1 xxxx xxxx xxxx xxxx xxxx */
DECODE_EMULATEX (0x0e100000, 0x04100000, PROBES_LOAD,
REGS(NOPCWB, ANY, 0, 0, 0)),
/* STR (register) cccc 011x x0x0 xxxx xxxx xxxx xxxx xxxx */
/* STRB (register) cccc 011x x1x0 xxxx xxxx xxxx xxxx xxxx */
DECODE_EMULATEX (0x0e100000, 0x06000000, PROBES_STORE,
REGS(NOPCWB, ANY, 0, 0, NOPC)),
/* LDR (register) cccc 011x x0x1 xxxx xxxx xxxx xxxx xxxx */
/* LDRB (register) cccc 011x x1x1 xxxx xxxx xxxx xxxx xxxx */
DECODE_EMULATEX (0x0e100000, 0x06100000, PROBES_LOAD,
REGS(NOPCWB, ANY, 0, 0, NOPC)),
DECODE_END
};
static const union decode_item arm_cccc_100x_table[] = {
/* Block data transfer instructions */
/* LDM cccc 100x x0x1 xxxx xxxx xxxx xxxx xxxx */
/* STM cccc 100x x0x0 xxxx xxxx xxxx xxxx xxxx */
DECODE_CUSTOM (0x0e400000, 0x08000000, PROBES_LDMSTM),
/* STM (user registers) cccc 100x x1x0 xxxx xxxx xxxx xxxx xxxx */
/* LDM (user registers) cccc 100x x1x1 xxxx 0xxx xxxx xxxx xxxx */
/* LDM (exception ret) cccc 100x x1x1 xxxx 1xxx xxxx xxxx xxxx */
DECODE_END
};
const union decode_item probes_decode_arm_table[] = {
/*
* Unconditional instructions
* 1111 xxxx xxxx xxxx xxxx xxxx xxxx xxxx
*/
DECODE_TABLE (0xf0000000, 0xf0000000, arm_1111_table),
/*
* Miscellaneous instructions
* cccc 0001 0xx0 xxxx xxxx xxxx 0xxx xxxx
*/
DECODE_TABLE (0x0f900080, 0x01000000, arm_cccc_0001_0xx0____0xxx_table),
/*
* Halfword multiply and multiply-accumulate
* cccc 0001 0xx0 xxxx xxxx xxxx 1xx0 xxxx
*/
DECODE_TABLE (0x0f900090, 0x01000080, arm_cccc_0001_0xx0____1xx0_table),
/*
* Multiply and multiply-accumulate
* cccc 0000 xxxx xxxx xxxx xxxx 1001 xxxx
*/
DECODE_TABLE (0x0f0000f0, 0x00000090, arm_cccc_0000_____1001_table),
/*
* Synchronization primitives
* cccc 0001 xxxx xxxx xxxx xxxx 1001 xxxx
*/
DECODE_TABLE (0x0f0000f0, 0x01000090, arm_cccc_0001_____1001_table),
/*
* Extra load/store instructions
* cccc 000x xxxx xxxx xxxx xxxx 1xx1 xxxx
*/
DECODE_TABLE (0x0e000090, 0x00000090, arm_cccc_000x_____1xx1_table),
/*
* Data-processing (register)
* cccc 000x xxxx xxxx xxxx xxxx xxx0 xxxx
* Data-processing (register-shifted register)
* cccc 000x xxxx xxxx xxxx xxxx 0xx1 xxxx
*/
DECODE_TABLE (0x0e000000, 0x00000000, arm_cccc_000x_table),
/*
* Data-processing (immediate)
* cccc 001x xxxx xxxx xxxx xxxx xxxx xxxx
*/
DECODE_TABLE (0x0e000000, 0x02000000, arm_cccc_001x_table),
/*
* Media instructions
* cccc 011x xxxx xxxx xxxx xxxx xxx1 xxxx
*/
DECODE_TABLE (0x0f000010, 0x06000010, arm_cccc_0110_____xxx1_table),
DECODE_TABLE (0x0f000010, 0x07000010, arm_cccc_0111_____xxx1_table),
/*
* Load/store word and unsigned byte
* cccc 01xx xxxx xxxx xxxx xxxx xxxx xxxx
*/
DECODE_TABLE (0x0c000000, 0x04000000, arm_cccc_01xx_table),
/*
* Block data transfer instructions
* cccc 100x xxxx xxxx xxxx xxxx xxxx xxxx
*/
DECODE_TABLE (0x0e000000, 0x08000000, arm_cccc_100x_table),
/* B cccc 1010 xxxx xxxx xxxx xxxx xxxx xxxx */
/* BL cccc 1011 xxxx xxxx xxxx xxxx xxxx xxxx */
DECODE_SIMULATE (0x0e000000, 0x0a000000, PROBES_BRANCH),
/*
* Supervisor Call, and coprocessor instructions
*/
/* MCRR cccc 1100 0100 xxxx xxxx xxxx xxxx xxxx */
/* MRRC cccc 1100 0101 xxxx xxxx xxxx xxxx xxxx */
/* LDC cccc 110x xxx1 xxxx xxxx xxxx xxxx xxxx */
/* STC cccc 110x xxx0 xxxx xxxx xxxx xxxx xxxx */
/* CDP cccc 1110 xxxx xxxx xxxx xxxx xxx0 xxxx */
/* MCR cccc 1110 xxx0 xxxx xxxx xxxx xxx1 xxxx */
/* MRC cccc 1110 xxx1 xxxx xxxx xxxx xxx1 xxxx */
/* SVC cccc 1111 xxxx xxxx xxxx xxxx xxxx xxxx */
DECODE_REJECT (0x0c000000, 0x0c000000),
DECODE_END
};
#ifdef CONFIG_ARM_KPROBES_TEST_MODULE
EXPORT_SYMBOL_GPL(probes_decode_arm_table);
#endif
static void __kprobes arm_singlestep(probes_opcode_t insn,
struct arch_probes_insn *asi, struct pt_regs *regs)
{
regs->ARM_pc += 4;
asi->insn_handler(insn, asi, regs);
}
/* Return:
* INSN_REJECTED If instruction is one not allowed to kprobe,
* INSN_GOOD If instruction is supported and uses instruction slot,
* INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
*
* For instructions we don't want to kprobe (INSN_REJECTED return result):
* These are generally ones that modify the processor state making
* them "hard" to simulate such as switches processor modes or
* make accesses in alternate modes. Any of these could be simulated
* if the work was put into it, but low return considering they
* should also be very rare.
*/
enum probes_insn __kprobes
arm_probes_decode_insn(probes_opcode_t insn, struct arch_probes_insn *asi,
bool emulate, const union decode_action *actions,
const struct decode_checker *checkers[])
{
asi->insn_singlestep = arm_singlestep;
asi->insn_check_cc = probes_condition_checks[insn>>28];
return probes_decode_insn(insn, asi, probes_decode_arm_table, false,
emulate, actions, checkers);
}