// SPDX-License-Identifier: GPL-2.0
/*
* Disassemble s390 instructions.
*
* Copyright IBM Corp. 2007
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
*/
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/kallsyms.h>
#include <linux/reboot.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/uaccess.h>
#include <linux/atomic.h>
#include <linux/io.h>
#include <asm/dis.h>
#include <asm/cpcmd.h>
#include <asm/lowcore.h>
#include <asm/debug.h>
#include <asm/irq.h>
/* Type of operand */
#define OPERAND_GPR 0x1 /* Operand printed as %rx */
#define OPERAND_FPR 0x2 /* Operand printed as %fx */
#define OPERAND_AR 0x4 /* Operand printed as %ax */
#define OPERAND_CR 0x8 /* Operand printed as %cx */
#define OPERAND_VR 0x10 /* Operand printed as %vx */
#define OPERAND_DISP 0x20 /* Operand printed as displacement */
#define OPERAND_BASE 0x40 /* Operand printed as base register */
#define OPERAND_INDEX 0x80 /* Operand printed as index register */
#define OPERAND_PCREL 0x100 /* Operand printed as pc-relative symbol */
#define OPERAND_SIGNED 0x200 /* Operand printed as signed value */
#define OPERAND_LENGTH 0x400 /* Operand printed as length (+1) */
struct s390_operand {
unsigned char bits; /* The number of bits in the operand. */
unsigned char shift; /* The number of bits to shift. */
unsigned short flags; /* One bit syntax flags. */
};
struct s390_insn {
union {
const char name[5];
struct {
unsigned char zero;
unsigned int offset;
} __packed;
};
unsigned char opfrag;
unsigned char format;
};
struct s390_opcode_offset {
unsigned char opcode;
unsigned char mask;
unsigned char byte;
unsigned short offset;
unsigned short count;
} __packed;
enum {
UNUSED,
A_8, /* Access reg. starting at position 8 */
A_12, /* Access reg. starting at position 12 */
A_24, /* Access reg. starting at position 24 */
A_28, /* Access reg. starting at position 28 */
B_16, /* Base register starting at position 16 */
B_32, /* Base register starting at position 32 */
C_8, /* Control reg. starting at position 8 */
C_12, /* Control reg. starting at position 12 */
D20_20, /* 20 bit displacement starting at 20 */
D_20, /* Displacement starting at position 20 */
D_36, /* Displacement starting at position 36 */
F_8, /* FPR starting at position 8 */
F_12, /* FPR starting at position 12 */
F_16, /* FPR starting at position 16 */
F_24, /* FPR starting at position 24 */
F_28, /* FPR starting at position 28 */
F_32, /* FPR starting at position 32 */
I8_8, /* 8 bit signed value starting at 8 */
I8_32, /* 8 bit signed value starting at 32 */
I16_16, /* 16 bit signed value starting at 16 */
I16_32, /* 16 bit signed value starting at 32 */
I32_16, /* 32 bit signed value starting at 16 */
J12_12, /* 12 bit PC relative offset at 12 */
J16_16, /* 16 bit PC relative offset at 16 */
J16_32, /* 16 bit PC relative offset at 32 */
J24_24, /* 24 bit PC relative offset at 24 */
J32_16, /* 32 bit PC relative offset at 16 */
L4_8, /* 4 bit length starting at position 8 */
L4_12, /* 4 bit length starting at position 12 */
L8_8, /* 8 bit length starting at position 8 */
R_8, /* GPR starting at position 8 */
R_12, /* GPR starting at position 12 */
R_16, /* GPR starting at position 16 */
R_24, /* GPR starting at position 24 */
R_28, /* GPR starting at position 28 */
U4_8, /* 4 bit unsigned value starting at 8 */
U4_12, /* 4 bit unsigned value starting at 12 */
U4_16, /* 4 bit unsigned value starting at 16 */
U4_20, /* 4 bit unsigned value starting at 20 */
U4_24, /* 4 bit unsigned value starting at 24 */
U4_28, /* 4 bit unsigned value starting at 28 */
U4_32, /* 4 bit unsigned value starting at 32 */
U4_36, /* 4 bit unsigned value starting at 36 */
U8_8, /* 8 bit unsigned value starting at 8 */
U8_16, /* 8 bit unsigned value starting at 16 */
U8_24, /* 8 bit unsigned value starting at 24 */
U8_28, /* 8 bit unsigned value starting at 28 */
U8_32, /* 8 bit unsigned value starting at 32 */
U12_16, /* 12 bit unsigned value starting at 16 */
U16_16, /* 16 bit unsigned value starting at 16 */
U16_32, /* 16 bit unsigned value starting at 32 */
U32_16, /* 32 bit unsigned value starting at 16 */
VX_12, /* Vector index register starting at position 12 */
V_8, /* Vector reg. starting at position 8 */
V_12, /* Vector reg. starting at position 12 */
V_16, /* Vector reg. starting at position 16 */
V_32, /* Vector reg. starting at position 32 */
X_12, /* Index register starting at position 12 */
};
static const struct s390_operand operands[] = {
[UNUSED] = { 0, 0, 0 },
[A_8] = { 4, 8, OPERAND_AR },
[A_12] = { 4, 12, OPERAND_AR },
[A_24] = { 4, 24, OPERAND_AR },
[A_28] = { 4, 28, OPERAND_AR },
[B_16] = { 4, 16, OPERAND_BASE | OPERAND_GPR },
[B_32] = { 4, 32, OPERAND_BASE | OPERAND_GPR },
[C_8] = { 4, 8, OPERAND_CR },
[C_12] = { 4, 12, OPERAND_CR },
[D20_20] = { 20, 20, OPERAND_DISP | OPERAND_SIGNED },
[D_20] = { 12, 20, OPERAND_DISP },
[D_36] = { 12, 36, OPERAND_DISP },
[F_8] = { 4, 8, OPERAND_FPR },
[F_12] = { 4, 12, OPERAND_FPR },
[F_16] = { 4, 16, OPERAND_FPR },
[F_24] = { 4, 24, OPERAND_FPR },
[F_28] = { 4, 28, OPERAND_FPR },
[F_32] = { 4, 32, OPERAND_FPR },
[I8_8] = { 8, 8, OPERAND_SIGNED },
[I8_32] = { 8, 32, OPERAND_SIGNED },
[I16_16] = { 16, 16, OPERAND_SIGNED },
[I16_32] = { 16, 32, OPERAND_SIGNED },
[I32_16] = { 32, 16, OPERAND_SIGNED },
[J12_12] = { 12, 12, OPERAND_PCREL },
[J16_16] = { 16, 16, OPERAND_PCREL },
[J16_32] = { 16, 32, OPERAND_PCREL },
[J24_24] = { 24, 24, OPERAND_PCREL },
[J32_16] = { 32, 16, OPERAND_PCREL },
[L4_8] = { 4, 8, OPERAND_LENGTH },
[L4_12] = { 4, 12, OPERAND_LENGTH },
[L8_8] = { 8, 8, OPERAND_LENGTH },
[R_8] = { 4, 8, OPERAND_GPR },
[R_12] = { 4, 12, OPERAND_GPR },
[R_16] = { 4, 16, OPERAND_GPR },
[R_24] = { 4, 24, OPERAND_GPR },
[R_28] = { 4, 28, OPERAND_GPR },
[U4_8] = { 4, 8, 0 },
[U4_12] = { 4, 12, 0 },
[U4_16] = { 4, 16, 0 },
[U4_20] = { 4, 20, 0 },
[U4_24] = { 4, 24, 0 },
[U4_28] = { 4, 28, 0 },
[U4_32] = { 4, 32, 0 },
[U4_36] = { 4, 36, 0 },
[U8_8] = { 8, 8, 0 },
[U8_16] = { 8, 16, 0 },
[U8_24] = { 8, 24, 0 },
[U8_28] = { 8, 28, 0 },
[U8_32] = { 8, 32, 0 },
[U12_16] = { 12, 16, 0 },
[U16_16] = { 16, 16, 0 },
[U16_32] = { 16, 32, 0 },
[U32_16] = { 32, 16, 0 },
[VX_12] = { 4, 12, OPERAND_INDEX | OPERAND_VR },
[V_8] = { 4, 8, OPERAND_VR },
[V_12] = { 4, 12, OPERAND_VR },
[V_16] = { 4, 16, OPERAND_VR },
[V_32] = { 4, 32, OPERAND_VR },
[X_12] = { 4, 12, OPERAND_INDEX | OPERAND_GPR },
};
static const unsigned char formats[][6] = {
[INSTR_E] = { 0, 0, 0, 0, 0, 0 },
[INSTR_IE_UU] = { U4_24, U4_28, 0, 0, 0, 0 },
[INSTR_MII_UPP] = { U4_8, J12_12, J24_24 },
[INSTR_RIE_R0IU] = { R_8, I16_16, U4_32, 0, 0, 0 },
[INSTR_RIE_R0UU] = { R_8, U16_16, U4_32, 0, 0, 0 },
[INSTR_RIE_RRI0] = { R_8, R_12, I16_16, 0, 0, 0 },
[INSTR_RIE_RRP] = { R_8, R_12, J16_16, 0, 0, 0 },
[INSTR_RIE_RRPU] = { R_8, R_12, U4_32, J16_16, 0, 0 },
[INSTR_RIE_RRUUU] = { R_8, R_12, U8_16, U8_24, U8_32, 0 },
[INSTR_RIE_RUI0] = { R_8, I16_16, U4_12, 0, 0, 0 },
[INSTR_RIE_RUPI] = { R_8, I8_32, U4_12, J16_16, 0, 0 },
[INSTR_RIE_RUPU] = { R_8, U8_32, U4_12, J16_16, 0, 0 },
[INSTR_RIL_RI] = { R_8, I32_16, 0, 0, 0, 0 },
[INSTR_RIL_RP] = { R_8, J32_16, 0, 0, 0, 0 },
[INSTR_RIL_RU] = { R_8, U32_16, 0, 0, 0, 0 },
[INSTR_RIL_UP] = { U4_8, J32_16, 0, 0, 0, 0 },
[INSTR_RIS_RURDI] = { R_8, I8_32, U4_12, D_20, B_16, 0 },
[INSTR_RIS_RURDU] = { R_8, U8_32, U4_12, D_20, B_16, 0 },
[INSTR_RI_RI] = { R_8, I16_16, 0, 0, 0, 0 },
[INSTR_RI_RP] = { R_8, J16_16, 0, 0, 0, 0 },
[INSTR_RI_RU] = { R_8, U16_16, 0, 0, 0, 0 },
[INSTR_RI_UP] = { U4_8, J16_16, 0, 0, 0, 0 },
[INSTR_RRE_00] = { 0, 0, 0, 0, 0, 0 },
[INSTR_RRE_AA] = { A_24, A_28, 0, 0, 0, 0 },
[INSTR_RRE_AR] = { A_24, R_28, 0, 0, 0, 0 },
[INSTR_RRE_F0] = { F_24, 0, 0, 0, 0, 0 },
[INSTR_RRE_FF] = { F_24, F_28, 0, 0, 0, 0 },
[INSTR_RRE_FR] = { F_24, R_28, 0, 0, 0, 0 },
[INSTR_RRE_R0] = { R_24, 0, 0, 0, 0, 0 },
[INSTR_RRE_RA] = { R_24, A_28, 0, 0, 0, 0 },
[INSTR_RRE_RF] = { R_24, F_28, 0, 0, 0, 0 },
[INSTR_RRE_RR] = { R_24, R_28, 0, 0, 0, 0 },
[INSTR_RRF_0UFF] = { F_24, F_28, U4_20, 0, 0, 0 },
[INSTR_RRF_0URF] = { R_24, F_28, U4_20, 0, 0, 0 },
[INSTR_RRF_F0FF] = { F_16, F_24, F_28, 0, 0, 0 },
[INSTR_RRF_F0FF2] = { F_24, F_16, F_28, 0, 0, 0 },
[INSTR_RRF_F0FR] = { F_24, F_16, R_28, 0, 0, 0 },
[INSTR_RRF_FFRU] = { F_24, F_16, R_28, U4_20, 0, 0 },
[INSTR_RRF_FUFF] = { F_24, F_16, F_28, U4_20, 0, 0 },
[INSTR_RRF_FUFF2] = { F_24, F_28, F_16, U4_20, 0, 0 },
[INSTR_RRF_R0RR] = { R_24, R_16, R_28, 0, 0, 0 },
[INSTR_RRF_R0RR2] = { R_24, R_28, R_16, 0, 0, 0 },
[INSTR_RRF_RURR] = { R_24, R_28, R_16, U4_20, 0, 0 },
[INSTR_RRF_RURR2] = { R_24, R_16, R_28, U4_20, 0, 0 },
[INSTR_RRF_U0FF] = { F_24, U4_16, F_28, 0, 0, 0 },
[INSTR_RRF_U0RF] = { R_24, U4_16, F_28, 0, 0, 0 },
[INSTR_RRF_U0RR] = { R_24, R_28, U4_16, 0, 0, 0 },
[INSTR_RRF_URR] = { R_24, R_28, U8_16, 0, 0, 0 },
[INSTR_RRF_UUFF] = { F_24, U4_16, F_28, U4_20, 0, 0 },
[INSTR_RRF_UUFR] = { F_24, U4_16, R_28, U4_20, 0, 0 },
[INSTR_RRF_UURF] = { R_24, U4_16, F_28, U4_20, 0, 0 },
[INSTR_RRS_RRRDU] = { R_8, R_12, U4_32, D_20, B_16 },
[INSTR_RR_FF] = { F_8, F_12, 0, 0, 0, 0 },
[INSTR_RR_R0] = { R_8, 0, 0, 0, 0, 0 },
[INSTR_RR_RR] = { R_8, R_12, 0, 0, 0, 0 },
[INSTR_RR_U0] = { U8_8, 0, 0, 0, 0, 0 },
[INSTR_RR_UR] = { U4_8, R_12, 0, 0, 0, 0 },
[INSTR_RSI_RRP] = { R_8, R_12, J16_16, 0, 0, 0 },
[INSTR_RSL_LRDFU] = { F_32, D_20, L8_8, B_16, U4_36, 0 },
[INSTR_RSL_R0RD] = { D_20, L4_8, B_16, 0, 0, 0 },
[INSTR_RSY_AARD] = { A_8, A_12, D20_20, B_16, 0, 0 },
[INSTR_RSY_CCRD] = { C_8, C_12, D20_20, B_16, 0, 0 },
[INSTR_RSY_RDRU] = { R_8, D20_20, B_16, U4_12, 0, 0 },
[INSTR_RSY_RRRD] = { R_8, R_12, D20_20, B_16, 0, 0 },
[INSTR_RSY_RURD] = { R_8, U4_12, D20_20, B_16, 0, 0 },
[INSTR_RSY_RURD2] = { R_8, D20_20, B_16, U4_12, 0, 0 },
[INSTR_RS_AARD] = { A_8, A_12, D_20, B_16, 0, 0 },
[INSTR_RS_CCRD] = { C_8, C_12, D_20, B_16, 0, 0 },
[INSTR_RS_R0RD] = { R_8, D_20, B_16, 0, 0, 0 },
[INSTR_RS_RRRD] = { R_8, R_12, D_20, B_16, 0, 0 },
[INSTR_RS_RURD] = { R_8, U4_12, D_20, B_16, 0, 0 },
[INSTR_RXE_FRRD] = { F_8, D_20, X_12, B_16, 0, 0 },
[INSTR_RXE_RRRDU] = { R_8, D_20, X_12, B_16, U4_32, 0 },
[INSTR_RXF_FRRDF] = { F_32, F_8, D_20, X_12, B_16, 0 },
[INSTR_RXY_FRRD] = { F_8, D20_20, X_12, B_16, 0, 0 },
[INSTR_RXY_RRRD] = { R_8, D20_20, X_12, B_16, 0, 0 },
[INSTR_RXY_URRD] = { U4_8, D20_20, X_12, B_16, 0, 0 },
[INSTR_RX_FRRD] = { F_8, D_20, X_12, B_16, 0, 0 },
[INSTR_RX_RRRD] = { R_8, D_20, X_12, B_16, 0, 0 },
[INSTR_RX_URRD] = { U4_8, D_20, X_12, B_16, 0, 0 },
[INSTR_SIL_RDI] = { D_20, B_16, I16_32, 0, 0, 0 },
[INSTR_SIL_RDU] = { D_20, B_16, U16_32, 0, 0, 0 },
[INSTR_SIY_IRD] = { D20_20, B_16, I8_8, 0, 0, 0 },
[INSTR_SIY_RD] = { D20_20, B_16, 0, 0, 0, 0 },
[INSTR_SIY_URD] = { D20_20, B_16, U8_8, 0, 0, 0 },
[INSTR_SI_RD] = { D_20, B_16, 0, 0, 0, 0 },
[INSTR_SI_URD] = { D_20, B_16, U8_8, 0, 0, 0 },
[INSTR_SMI_U0RDP] = { U4_8, J16_32, D_20, B_16, 0, 0 },
[INSTR_SSE_RDRD] = { D_20, B_16, D_36, B_32, 0, 0 },
[INSTR_SSF_RRDRD] = { D_20, B_16, D_36, B_32, R_8, 0 },
[INSTR_SSF_RRDRD2] = { R_8, D_20, B_16, D_36, B_32, 0 },
[INSTR_SS_L0RDRD] = { D_20, L8_8, B_16, D_36, B_32, 0 },
[INSTR_SS_L2RDRD] = { D_20, B_16, D_36, L8_8, B_32, 0 },
[INSTR_SS_LIRDRD] = { D_20, L4_8, B_16, D_36, B_32, U4_12 },
[INSTR_SS_LLRDRD] = { D_20, L4_8, B_16, D_36, L4_12, B_32 },
[INSTR_SS_RRRDRD] = { D_20, R_8, B_16, D_36, B_32, R_12 },
[INSTR_SS_RRRDRD2] = { R_8, D_20, B_16, R_12, D_36, B_32 },
[INSTR_SS_RRRDRD3] = { R_8, R_12, D_20, B_16, D_36, B_32 },
[INSTR_S_00] = { 0, 0, 0, 0, 0, 0 },
[INSTR_S_RD] = { D_20, B_16, 0, 0, 0, 0 },
[INSTR_VRI_V0IU] = { V_8, I16_16, U4_32, 0, 0, 0 },
[INSTR_VRI_V0U] = { V_8, U16_16, 0, 0, 0, 0 },
[INSTR_VRI_V0UU2] = { V_8, U16_16, U4_32, 0, 0, 0 },
[INSTR_VRI_V0UUU] = { V_8, U8_16, U8_24, U4_32, 0, 0 },
[INSTR_VRI_VR0UU] = { V_8, R_12, U8_28, U4_24, 0, 0 },
[INSTR_VRI_VVUU] = { V_8, V_12, U16_16, U4_32, 0, 0 },
[INSTR_VRI_VVUUU] = { V_8, V_12, U12_16, U4_32, U4_28, 0 },
[INSTR_VRI_VVUUU2] = { V_8, V_12, U8_28, U8_16, U4_24, 0 },
[INSTR_VRI_VVV0U] = { V_8, V_12, V_16, U8_24, 0, 0 },
[INSTR_VRI_VVV0UU] = { V_8, V_12, V_16, U8_24, U4_32, 0 },
[INSTR_VRI_VVV0UU2] = { V_8, V_12, V_16, U8_28, U4_24, 0 },
[INSTR_VRR_0V] = { V_12, 0, 0, 0, 0, 0 },
[INSTR_VRR_0VV0U] = { V_12, V_16, U4_24, 0, 0, 0 },
[INSTR_VRR_RV0UU] = { R_8, V_12, U4_24, U4_28, 0, 0 },
[INSTR_VRR_VRR] = { V_8, R_12, R_16, 0, 0, 0 },
[INSTR_VRR_VV] = { V_8, V_12, 0, 0, 0, 0 },
[INSTR_VRR_VV0U] = { V_8, V_12, U4_32, 0, 0, 0 },
[INSTR_VRR_VV0U0U] = { V_8, V_12, U4_32, U4_24, 0, 0 },
[INSTR_VRR_VV0U2] = { V_8, V_12, U4_24, 0, 0, 0 },
[INSTR_VRR_VV0UU2] = { V_8, V_12, U4_32, U4_28, 0, 0 },
[INSTR_VRR_VV0UUU] = { V_8, V_12, U4_32, U4_28, U4_24, 0 },
[INSTR_VRR_VVV] = { V_8, V_12, V_16, 0, 0, 0 },
[INSTR_VRR_VVV0U] = { V_8, V_12, V_16, U4_32, 0, 0 },
[INSTR_VRR_VVV0U0] = { V_8, V_12, V_16, U4_24, 0, 0 },
[INSTR_VRR_VVV0U0U] = { V_8, V_12, V_16, U4_32, U4_24, 0 },
[INSTR_VRR_VVV0UU] = { V_8, V_12, V_16, U4_32, U4_28, 0 },
[INSTR_VRR_VVV0UUU] = { V_8, V_12, V_16, U4_32, U4_28, U4_24 },
[INSTR_VRR_VVV0V] = { V_8, V_12, V_16, V_32, 0, 0 },
[INSTR_VRR_VVVU0UV] = { V_8, V_12, V_16, V_32, U4_28, U4_20 },
[INSTR_VRR_VVVU0V] = { V_8, V_12, V_16, V_32, U4_20, 0 },
[INSTR_VRR_VVVUU0V] = { V_8, V_12, V_16, V_32, U4_20, U4_24 },
[INSTR_VRS_RRDV] = { V_32, R_12, D_20, B_16, 0, 0 },
[INSTR_VRS_RVRDU] = { R_8, V_12, D_20, B_16, U4_32, 0 },
[INSTR_VRS_VRRD] = { V_8, R_12, D_20, B_16, 0, 0 },
[INSTR_VRS_VRRDU] = { V_8, R_12, D_20, B_16, U4_32, 0 },
[INSTR_VRS_VVRDU] = { V_8, V_12, D_20, B_16, U4_32, 0 },
[INSTR_VRV_VVXRDU] = { V_8, D_20, VX_12, B_16, U4_32, 0 },
[INSTR_VRX_VRRDU] = { V_8, D_20, X_12, B_16, U4_32, 0 },
[INSTR_VRX_VV] = { V_8, V_12, 0, 0, 0, 0 },
[INSTR_VSI_URDV] = { V_32, D_20, B_16, U8_8, 0, 0 },
};
static char long_insn_name[][7] = LONG_INSN_INITIALIZER;
static struct s390_insn opcode[] = OPCODE_TABLE_INITIALIZER;
static struct s390_opcode_offset opcode_offset[] = OPCODE_OFFSET_INITIALIZER;
/* Extracts an operand value from an instruction. */
static unsigned int extract_operand(unsigned char *code,
const struct s390_operand *operand)
{
unsigned char *cp;
unsigned int val;
int bits;
/* Extract fragments of the operand byte for byte. */
cp = code + operand->shift / 8;
bits = (operand->shift & 7) + operand->bits;
val = 0;
do {
val <<= 8;
val |= (unsigned int) *cp++;
bits -= 8;
} while (bits > 0);
val >>= -bits;
val &= ((1U << (operand->bits - 1)) << 1) - 1;
/* Check for special long displacement case. */
if (operand->bits == 20 && operand->shift == 20)
val = (val & 0xff) << 12 | (val & 0xfff00) >> 8;
/* Check for register extensions bits for vector registers. */
if (operand->flags & OPERAND_VR) {
if (operand->shift == 8)
val |= (code[4] & 8) << 1;
else if (operand->shift == 12)
val |= (code[4] & 4) << 2;
else if (operand->shift == 16)
val |= (code[4] & 2) << 3;
else if (operand->shift == 32)
val |= (code[4] & 1) << 4;
}
/* Sign extend value if the operand is signed or pc relative. */
if ((operand->flags & (OPERAND_SIGNED | OPERAND_PCREL)) &&
(val & (1U << (operand->bits - 1))))
val |= (-1U << (operand->bits - 1)) << 1;
/* Double value if the operand is pc relative. */
if (operand->flags & OPERAND_PCREL)
val <<= 1;
/* Length x in an instructions has real length x + 1. */
if (operand->flags & OPERAND_LENGTH)
val++;
return val;
}
struct s390_insn *find_insn(unsigned char *code)
{
struct s390_opcode_offset *entry;
struct s390_insn *insn;
unsigned char opfrag;
int i;
/* Search the opcode offset table to find an entry which
* matches the beginning of the opcode. If there is no match
* the last entry will be used, which is the default entry for
* unknown instructions as well as 1-byte opcode instructions.
*/
for (i = 0; i < ARRAY_SIZE(opcode_offset); i++) {
entry = &opcode_offset[i];
if (entry->opcode == code[0])
break;
}
opfrag = *(code + entry->byte) & entry->mask;
insn = &opcode[entry->offset];
for (i = 0; i < entry->count; i++) {
if (insn->opfrag == opfrag)
return insn;
insn++;
}
return NULL;
}
static int print_insn(char *buffer, unsigned char *code, unsigned long addr)
{
struct s390_insn *insn;
const unsigned char *ops;
const struct s390_operand *operand;
unsigned int value;
char separator;
char *ptr;
int i;
ptr = buffer;
insn = find_insn(code);
if (insn) {
if (insn->zero == 0)
ptr += sprintf(ptr, "%.7s\t",
long_insn_name[insn->offset]);
else
ptr += sprintf(ptr, "%.5s\t", insn->name);
/* Extract the operands. */
separator = 0;
for (ops = formats[insn->format], i = 0;
*ops != 0 && i < 6; ops++, i++) {
operand = operands + *ops;
value = extract_operand(code, operand);
if ((operand->flags & OPERAND_INDEX) && value == 0)
continue;
if ((operand->flags & OPERAND_BASE) &&
value == 0 && separator == '(') {
separator = ',';
continue;
}
if (separator)
ptr += sprintf(ptr, "%c", separator);
if (operand->flags & OPERAND_GPR)
ptr += sprintf(ptr, "%%r%i", value);
else if (operand->flags & OPERAND_FPR)
ptr += sprintf(ptr, "%%f%i", value);
else if (operand->flags & OPERAND_AR)
ptr += sprintf(ptr, "%%a%i", value);
else if (operand->flags & OPERAND_CR)
ptr += sprintf(ptr, "%%c%i", value);
else if (operand->flags & OPERAND_VR)
ptr += sprintf(ptr, "%%v%i", value);
else if (operand->flags & OPERAND_PCREL) {
void *pcrel = (void *)((int)value + addr);
ptr += sprintf(ptr, "%px", pcrel);
} else if (operand->flags & OPERAND_SIGNED)
ptr += sprintf(ptr, "%i", value);
else
ptr += sprintf(ptr, "%u", value);
if (operand->flags & OPERAND_DISP)
separator = '(';
else if (operand->flags & OPERAND_BASE) {
ptr += sprintf(ptr, ")");
separator = ',';
} else
separator = ',';
}
} else
ptr += sprintf(ptr, "unknown");
return (int) (ptr - buffer);
}
static int copy_from_regs(struct pt_regs *regs, void *dst, void *src, int len)
{
if (user_mode(regs)) {
if (copy_from_user(dst, (char __user *)src, len))
return -EFAULT;
} else {
if (copy_from_kernel_nofault(dst, src, len))
return -EFAULT;
}
return 0;
}
void show_code(struct pt_regs *regs)
{
char *mode = user_mode(regs) ? "User" : "Krnl";
unsigned char code[64];
char buffer[128], *ptr;
unsigned long addr;
int start, end, opsize, hops, i;
/* Get a snapshot of the 64 bytes surrounding the fault address. */
for (start = 32; start && regs->psw.addr >= 34 - start; start -= 2) {
addr = regs->psw.addr - 34 + start;
if (copy_from_regs(regs, code + start - 2, (void *)addr, 2))
break;
}
for (end = 32; end < 64; end += 2) {
addr = regs->psw.addr + end - 32;
if (copy_from_regs(regs, code + end, (void *)addr, 2))
break;
}
/* Code snapshot usable ? */
if ((regs->psw.addr & 1) || start >= end) {
printk("%s Code: Bad PSW.\n", mode);
return;
}
/* Find a starting point for the disassembly. */
while (start < 32) {
for (i = 0, hops = 0; start + i < 32 && hops < 3; hops++) {
if (!find_insn(code + start + i))
break;
i += insn_length(code[start + i]);
}
if (start + i == 32)
/* Looks good, sequence ends at PSW. */
break;
start += 2;
}
/* Decode the instructions. */
ptr = buffer;
ptr += sprintf(ptr, "%s Code:", mode);
hops = 0;
while (start < end && hops < 8) {
opsize = insn_length(code[start]);
if (start + opsize == 32)
*ptr++ = '#';
else if (start == 32)
*ptr++ = '>';
else
*ptr++ = ' ';
addr = regs->psw.addr + start - 32;
ptr += sprintf(ptr, "%px: ", (void *)addr);
if (start + opsize >= end)
break;
for (i = 0; i < opsize; i++)
ptr += sprintf(ptr, "%02x", code[start + i]);
*ptr++ = '\t';
if (i < 6)
*ptr++ = '\t';
ptr += print_insn(ptr, code + start, addr);
start += opsize;
pr_cont("%s", buffer);
ptr = buffer;
ptr += sprintf(ptr, "\n ");
hops++;
}
pr_cont("\n");
}
void print_fn_code(unsigned char *code, unsigned long len)
{
char buffer[128], *ptr;
int opsize, i;
while (len) {
ptr = buffer;
opsize = insn_length(*code);
if (opsize > len)
break;
ptr += sprintf(ptr, "%px: ", code);
for (i = 0; i < opsize; i++)
ptr += sprintf(ptr, "%02x", code[i]);
*ptr++ = '\t';
if (i < 4)
*ptr++ = '\t';
ptr += print_insn(ptr, code, (unsigned long) code);
*ptr++ = '\n';
*ptr++ = 0;
printk("%s", buffer);
code += opsize;
len -= opsize;
}
}