xref: /openbmc/linux/arch/s390/kernel/dis.c (revision c4e78957)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Disassemble s390 instructions.
4  *
5  * Copyright IBM Corp. 2007
6  * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7  */
8 
9 #include <linux/sched.h>
10 #include <linux/kernel.h>
11 #include <linux/string.h>
12 #include <linux/errno.h>
13 #include <linux/ptrace.h>
14 #include <linux/timer.h>
15 #include <linux/mm.h>
16 #include <linux/smp.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/delay.h>
20 #include <linux/export.h>
21 #include <linux/kallsyms.h>
22 #include <linux/reboot.h>
23 #include <linux/kprobes.h>
24 #include <linux/kdebug.h>
25 #include <linux/uaccess.h>
26 #include <linux/atomic.h>
27 #include <asm/dis.h>
28 #include <asm/io.h>
29 #include <asm/cpcmd.h>
30 #include <asm/lowcore.h>
31 #include <asm/debug.h>
32 #include <asm/irq.h>
33 
34 /* Type of operand */
35 #define OPERAND_GPR	0x1	/* Operand printed as %rx */
36 #define OPERAND_FPR	0x2	/* Operand printed as %fx */
37 #define OPERAND_AR	0x4	/* Operand printed as %ax */
38 #define OPERAND_CR	0x8	/* Operand printed as %cx */
39 #define OPERAND_VR	0x10	/* Operand printed as %vx */
40 #define OPERAND_DISP	0x20	/* Operand printed as displacement */
41 #define OPERAND_BASE	0x40	/* Operand printed as base register */
42 #define OPERAND_INDEX	0x80	/* Operand printed as index register */
43 #define OPERAND_PCREL	0x100	/* Operand printed as pc-relative symbol */
44 #define OPERAND_SIGNED	0x200	/* Operand printed as signed value */
45 #define OPERAND_LENGTH	0x400	/* Operand printed as length (+1) */
46 
47 struct s390_operand {
48 	unsigned char bits;	/* The number of bits in the operand. */
49 	unsigned char shift;	/* The number of bits to shift. */
50 	unsigned short flags;	/* One bit syntax flags. */
51 };
52 
53 struct s390_insn {
54 	union {
55 		const char name[5];
56 		struct {
57 			unsigned char zero;
58 			unsigned int offset;
59 		} __packed;
60 	};
61 	unsigned char opfrag;
62 	unsigned char format;
63 };
64 
65 struct s390_opcode_offset {
66 	unsigned char opcode;
67 	unsigned char mask;
68 	unsigned char byte;
69 	unsigned short offset;
70 	unsigned short count;
71 } __packed;
72 
73 enum {
74 	UNUSED,
75 	A_8,	/* Access reg. starting at position 8 */
76 	A_12,	/* Access reg. starting at position 12 */
77 	A_24,	/* Access reg. starting at position 24 */
78 	A_28,	/* Access reg. starting at position 28 */
79 	B_16,	/* Base register starting at position 16 */
80 	B_32,	/* Base register starting at position 32 */
81 	C_8,	/* Control reg. starting at position 8 */
82 	C_12,	/* Control reg. starting at position 12 */
83 	D20_20, /* 20 bit displacement starting at 20 */
84 	D_20,	/* Displacement starting at position 20 */
85 	D_36,	/* Displacement starting at position 36 */
86 	F_8,	/* FPR starting at position 8 */
87 	F_12,	/* FPR starting at position 12 */
88 	F_16,	/* FPR starting at position 16 */
89 	F_24,	/* FPR starting at position 24 */
90 	F_28,	/* FPR starting at position 28 */
91 	F_32,	/* FPR starting at position 32 */
92 	I8_8,	/* 8 bit signed value starting at 8 */
93 	I8_32,	/* 8 bit signed value starting at 32 */
94 	I16_16, /* 16 bit signed value starting at 16 */
95 	I16_32, /* 16 bit signed value starting at 32 */
96 	I32_16, /* 32 bit signed value starting at 16 */
97 	J12_12, /* 12 bit PC relative offset at 12 */
98 	J16_16, /* 16 bit PC relative offset at 16 */
99 	J16_32, /* 16 bit PC relative offset at 32 */
100 	J24_24, /* 24 bit PC relative offset at 24 */
101 	J32_16, /* 32 bit PC relative offset at 16 */
102 	L4_8,	/* 4 bit length starting at position 8 */
103 	L4_12,	/* 4 bit length starting at position 12 */
104 	L8_8,	/* 8 bit length starting at position 8 */
105 	R_8,	/* GPR starting at position 8 */
106 	R_12,	/* GPR starting at position 12 */
107 	R_16,	/* GPR starting at position 16 */
108 	R_24,	/* GPR starting at position 24 */
109 	R_28,	/* GPR starting at position 28 */
110 	U4_8,	/* 4 bit unsigned value starting at 8 */
111 	U4_12,	/* 4 bit unsigned value starting at 12 */
112 	U4_16,	/* 4 bit unsigned value starting at 16 */
113 	U4_20,	/* 4 bit unsigned value starting at 20 */
114 	U4_24,	/* 4 bit unsigned value starting at 24 */
115 	U4_28,	/* 4 bit unsigned value starting at 28 */
116 	U4_32,	/* 4 bit unsigned value starting at 32 */
117 	U4_36,	/* 4 bit unsigned value starting at 36 */
118 	U8_8,	/* 8 bit unsigned value starting at 8 */
119 	U8_16,	/* 8 bit unsigned value starting at 16 */
120 	U8_24,	/* 8 bit unsigned value starting at 24 */
121 	U8_28,	/* 8 bit unsigned value starting at 28 */
122 	U8_32,	/* 8 bit unsigned value starting at 32 */
123 	U12_16, /* 12 bit unsigned value starting at 16 */
124 	U16_16, /* 16 bit unsigned value starting at 16 */
125 	U16_32, /* 16 bit unsigned value starting at 32 */
126 	U32_16, /* 32 bit unsigned value starting at 16 */
127 	VX_12,	/* Vector index register starting at position 12 */
128 	V_8,	/* Vector reg. starting at position 8 */
129 	V_12,	/* Vector reg. starting at position 12 */
130 	V_16,	/* Vector reg. starting at position 16 */
131 	V_32,	/* Vector reg. starting at position 32 */
132 	X_12,	/* Index register starting at position 12 */
133 };
134 
135 static const struct s390_operand operands[] = {
136 	[UNUSED] = {  0,  0, 0 },
137 	[A_8]	 = {  4,  8, OPERAND_AR },
138 	[A_12]	 = {  4, 12, OPERAND_AR },
139 	[A_24]	 = {  4, 24, OPERAND_AR },
140 	[A_28]	 = {  4, 28, OPERAND_AR },
141 	[B_16]	 = {  4, 16, OPERAND_BASE | OPERAND_GPR },
142 	[B_32]	 = {  4, 32, OPERAND_BASE | OPERAND_GPR },
143 	[C_8]	 = {  4,  8, OPERAND_CR },
144 	[C_12]	 = {  4, 12, OPERAND_CR },
145 	[D20_20] = { 20, 20, OPERAND_DISP | OPERAND_SIGNED },
146 	[D_20]	 = { 12, 20, OPERAND_DISP },
147 	[D_36]	 = { 12, 36, OPERAND_DISP },
148 	[F_8]	 = {  4,  8, OPERAND_FPR },
149 	[F_12]	 = {  4, 12, OPERAND_FPR },
150 	[F_16]	 = {  4, 16, OPERAND_FPR },
151 	[F_24]	 = {  4, 24, OPERAND_FPR },
152 	[F_28]	 = {  4, 28, OPERAND_FPR },
153 	[F_32]	 = {  4, 32, OPERAND_FPR },
154 	[I8_8]	 = {  8,  8, OPERAND_SIGNED },
155 	[I8_32]	 = {  8, 32, OPERAND_SIGNED },
156 	[I16_16] = { 16, 16, OPERAND_SIGNED },
157 	[I16_32] = { 16, 32, OPERAND_SIGNED },
158 	[I32_16] = { 32, 16, OPERAND_SIGNED },
159 	[J12_12] = { 12, 12, OPERAND_PCREL },
160 	[J16_16] = { 16, 16, OPERAND_PCREL },
161 	[J16_32] = { 16, 32, OPERAND_PCREL },
162 	[J24_24] = { 24, 24, OPERAND_PCREL },
163 	[J32_16] = { 32, 16, OPERAND_PCREL },
164 	[L4_8]	 = {  4,  8, OPERAND_LENGTH },
165 	[L4_12]	 = {  4, 12, OPERAND_LENGTH },
166 	[L8_8]	 = {  8,  8, OPERAND_LENGTH },
167 	[R_8]	 = {  4,  8, OPERAND_GPR },
168 	[R_12]	 = {  4, 12, OPERAND_GPR },
169 	[R_16]	 = {  4, 16, OPERAND_GPR },
170 	[R_24]	 = {  4, 24, OPERAND_GPR },
171 	[R_28]	 = {  4, 28, OPERAND_GPR },
172 	[U4_8]	 = {  4,  8, 0 },
173 	[U4_12]	 = {  4, 12, 0 },
174 	[U4_16]	 = {  4, 16, 0 },
175 	[U4_20]	 = {  4, 20, 0 },
176 	[U4_24]	 = {  4, 24, 0 },
177 	[U4_28]	 = {  4, 28, 0 },
178 	[U4_32]	 = {  4, 32, 0 },
179 	[U4_36]	 = {  4, 36, 0 },
180 	[U8_8]	 = {  8,  8, 0 },
181 	[U8_16]	 = {  8, 16, 0 },
182 	[U8_24]	 = {  8, 24, 0 },
183 	[U8_28]	 = {  8, 28, 0 },
184 	[U8_32]	 = {  8, 32, 0 },
185 	[U12_16] = { 12, 16, 0 },
186 	[U16_16] = { 16, 16, 0 },
187 	[U16_32] = { 16, 32, 0 },
188 	[U32_16] = { 32, 16, 0 },
189 	[VX_12]	 = {  4, 12, OPERAND_INDEX | OPERAND_VR },
190 	[V_8]	 = {  4,  8, OPERAND_VR },
191 	[V_12]	 = {  4, 12, OPERAND_VR },
192 	[V_16]	 = {  4, 16, OPERAND_VR },
193 	[V_32]	 = {  4, 32, OPERAND_VR },
194 	[X_12]	 = {  4, 12, OPERAND_INDEX | OPERAND_GPR },
195 };
196 
197 static const unsigned char formats[][6] = {
198 	[INSTR_E]	     = { 0, 0, 0, 0, 0, 0 },
199 	[INSTR_IE_UU]	     = { U4_24, U4_28, 0, 0, 0, 0 },
200 	[INSTR_MII_UPP]	     = { U4_8, J12_12, J24_24 },
201 	[INSTR_RIE_R0IU]     = { R_8, I16_16, U4_32, 0, 0, 0 },
202 	[INSTR_RIE_R0UU]     = { R_8, U16_16, U4_32, 0, 0, 0 },
203 	[INSTR_RIE_RRI0]     = { R_8, R_12, I16_16, 0, 0, 0 },
204 	[INSTR_RIE_RRP]	     = { R_8, R_12, J16_16, 0, 0, 0 },
205 	[INSTR_RIE_RRPU]     = { R_8, R_12, U4_32, J16_16, 0, 0 },
206 	[INSTR_RIE_RRUUU]    = { R_8, R_12, U8_16, U8_24, U8_32, 0 },
207 	[INSTR_RIE_RUI0]     = { R_8, I16_16, U4_12, 0, 0, 0 },
208 	[INSTR_RIE_RUPI]     = { R_8, I8_32, U4_12, J16_16, 0, 0 },
209 	[INSTR_RIE_RUPU]     = { R_8, U8_32, U4_12, J16_16, 0, 0 },
210 	[INSTR_RIL_RI]	     = { R_8, I32_16, 0, 0, 0, 0 },
211 	[INSTR_RIL_RP]	     = { R_8, J32_16, 0, 0, 0, 0 },
212 	[INSTR_RIL_RU]	     = { R_8, U32_16, 0, 0, 0, 0 },
213 	[INSTR_RIL_UP]	     = { U4_8, J32_16, 0, 0, 0, 0 },
214 	[INSTR_RIS_RURDI]    = { R_8, I8_32, U4_12, D_20, B_16, 0 },
215 	[INSTR_RIS_RURDU]    = { R_8, U8_32, U4_12, D_20, B_16, 0 },
216 	[INSTR_RI_RI]	     = { R_8, I16_16, 0, 0, 0, 0 },
217 	[INSTR_RI_RP]	     = { R_8, J16_16, 0, 0, 0, 0 },
218 	[INSTR_RI_RU]	     = { R_8, U16_16, 0, 0, 0, 0 },
219 	[INSTR_RI_UP]	     = { U4_8, J16_16, 0, 0, 0, 0 },
220 	[INSTR_RRE_00]	     = { 0, 0, 0, 0, 0, 0 },
221 	[INSTR_RRE_AA]	     = { A_24, A_28, 0, 0, 0, 0 },
222 	[INSTR_RRE_AR]	     = { A_24, R_28, 0, 0, 0, 0 },
223 	[INSTR_RRE_F0]	     = { F_24, 0, 0, 0, 0, 0 },
224 	[INSTR_RRE_FF]	     = { F_24, F_28, 0, 0, 0, 0 },
225 	[INSTR_RRE_FR]	     = { F_24, R_28, 0, 0, 0, 0 },
226 	[INSTR_RRE_R0]	     = { R_24, 0, 0, 0, 0, 0 },
227 	[INSTR_RRE_RA]	     = { R_24, A_28, 0, 0, 0, 0 },
228 	[INSTR_RRE_RF]	     = { R_24, F_28, 0, 0, 0, 0 },
229 	[INSTR_RRE_RR]	     = { R_24, R_28, 0, 0, 0, 0 },
230 	[INSTR_RRF_0UFF]     = { F_24, F_28, U4_20, 0, 0, 0 },
231 	[INSTR_RRF_0URF]     = { R_24, F_28, U4_20, 0, 0, 0 },
232 	[INSTR_RRF_F0FF]     = { F_16, F_24, F_28, 0, 0, 0 },
233 	[INSTR_RRF_F0FF2]    = { F_24, F_16, F_28, 0, 0, 0 },
234 	[INSTR_RRF_F0FR]     = { F_24, F_16, R_28, 0, 0, 0 },
235 	[INSTR_RRF_FFRU]     = { F_24, F_16, R_28, U4_20, 0, 0 },
236 	[INSTR_RRF_FUFF]     = { F_24, F_16, F_28, U4_20, 0, 0 },
237 	[INSTR_RRF_FUFF2]    = { F_24, F_28, F_16, U4_20, 0, 0 },
238 	[INSTR_RRF_R0RR]     = { R_24, R_16, R_28, 0, 0, 0 },
239 	[INSTR_RRF_R0RR2]    = { R_24, R_28, R_16, 0, 0, 0 },
240 	[INSTR_RRF_RURR]     = { R_24, R_28, R_16, U4_20, 0, 0 },
241 	[INSTR_RRF_RURR2]    = { R_24, R_16, R_28, U4_20, 0, 0 },
242 	[INSTR_RRF_U0FF]     = { F_24, U4_16, F_28, 0, 0, 0 },
243 	[INSTR_RRF_U0RF]     = { R_24, U4_16, F_28, 0, 0, 0 },
244 	[INSTR_RRF_U0RR]     = { R_24, R_28, U4_16, 0, 0, 0 },
245 	[INSTR_RRF_URR]	     = { R_24, R_28, U8_16, 0, 0, 0 },
246 	[INSTR_RRF_UUFF]     = { F_24, U4_16, F_28, U4_20, 0, 0 },
247 	[INSTR_RRF_UUFR]     = { F_24, U4_16, R_28, U4_20, 0, 0 },
248 	[INSTR_RRF_UURF]     = { R_24, U4_16, F_28, U4_20, 0, 0 },
249 	[INSTR_RRS_RRRDU]    = { R_8, R_12, U4_32, D_20, B_16 },
250 	[INSTR_RR_FF]	     = { F_8, F_12, 0, 0, 0, 0 },
251 	[INSTR_RR_R0]	     = { R_8,  0, 0, 0, 0, 0 },
252 	[INSTR_RR_RR]	     = { R_8, R_12, 0, 0, 0, 0 },
253 	[INSTR_RR_U0]	     = { U8_8,	0, 0, 0, 0, 0 },
254 	[INSTR_RR_UR]	     = { U4_8, R_12, 0, 0, 0, 0 },
255 	[INSTR_RSI_RRP]	     = { R_8, R_12, J16_16, 0, 0, 0 },
256 	[INSTR_RSL_LRDFU]    = { F_32, D_20, L8_8, B_16, U4_36, 0 },
257 	[INSTR_RSL_R0RD]     = { D_20, L4_8, B_16, 0, 0, 0 },
258 	[INSTR_RSY_AARD]     = { A_8, A_12, D20_20, B_16, 0, 0 },
259 	[INSTR_RSY_CCRD]     = { C_8, C_12, D20_20, B_16, 0, 0 },
260 	[INSTR_RSY_RDRU]     = { R_8, D20_20, B_16, U4_12, 0, 0 },
261 	[INSTR_RSY_RRRD]     = { R_8, R_12, D20_20, B_16, 0, 0 },
262 	[INSTR_RSY_RURD]     = { R_8, U4_12, D20_20, B_16, 0, 0 },
263 	[INSTR_RSY_RURD2]    = { R_8, D20_20, B_16, U4_12, 0, 0 },
264 	[INSTR_RS_AARD]	     = { A_8, A_12, D_20, B_16, 0, 0 },
265 	[INSTR_RS_CCRD]	     = { C_8, C_12, D_20, B_16, 0, 0 },
266 	[INSTR_RS_R0RD]	     = { R_8, D_20, B_16, 0, 0, 0 },
267 	[INSTR_RS_RRRD]	     = { R_8, R_12, D_20, B_16, 0, 0 },
268 	[INSTR_RS_RURD]	     = { R_8, U4_12, D_20, B_16, 0, 0 },
269 	[INSTR_RXE_FRRD]     = { F_8, D_20, X_12, B_16, 0, 0 },
270 	[INSTR_RXE_RRRDU]    = { R_8, D_20, X_12, B_16, U4_32, 0 },
271 	[INSTR_RXF_FRRDF]    = { F_32, F_8, D_20, X_12, B_16, 0 },
272 	[INSTR_RXY_FRRD]     = { F_8, D20_20, X_12, B_16, 0, 0 },
273 	[INSTR_RXY_RRRD]     = { R_8, D20_20, X_12, B_16, 0, 0 },
274 	[INSTR_RXY_URRD]     = { U4_8, D20_20, X_12, B_16, 0, 0 },
275 	[INSTR_RX_FRRD]	     = { F_8, D_20, X_12, B_16, 0, 0 },
276 	[INSTR_RX_RRRD]	     = { R_8, D_20, X_12, B_16, 0, 0 },
277 	[INSTR_RX_URRD]	     = { U4_8, D_20, X_12, B_16, 0, 0 },
278 	[INSTR_SIL_RDI]	     = { D_20, B_16, I16_32, 0, 0, 0 },
279 	[INSTR_SIL_RDU]	     = { D_20, B_16, U16_32, 0, 0, 0 },
280 	[INSTR_SIY_IRD]	     = { D20_20, B_16, I8_8, 0, 0, 0 },
281 	[INSTR_SIY_RD]	     = { D20_20, B_16, 0, 0, 0, 0 },
282 	[INSTR_SIY_URD]	     = { D20_20, B_16, U8_8, 0, 0, 0 },
283 	[INSTR_SI_RD]	     = { D_20, B_16, 0, 0, 0, 0 },
284 	[INSTR_SI_URD]	     = { D_20, B_16, U8_8, 0, 0, 0 },
285 	[INSTR_SMI_U0RDP]    = { U4_8, J16_32, D_20, B_16, 0, 0 },
286 	[INSTR_SSE_RDRD]     = { D_20, B_16, D_36, B_32, 0, 0 },
287 	[INSTR_SSF_RRDRD]    = { D_20, B_16, D_36, B_32, R_8, 0 },
288 	[INSTR_SSF_RRDRD2]   = { R_8, D_20, B_16, D_36, B_32, 0 },
289 	[INSTR_SS_L0RDRD]    = { D_20, L8_8, B_16, D_36, B_32, 0 },
290 	[INSTR_SS_L2RDRD]    = { D_20, B_16, D_36, L8_8, B_32, 0 },
291 	[INSTR_SS_LIRDRD]    = { D_20, L4_8, B_16, D_36, B_32, U4_12 },
292 	[INSTR_SS_LLRDRD]    = { D_20, L4_8, B_16, D_36, L4_12, B_32 },
293 	[INSTR_SS_RRRDRD]    = { D_20, R_8, B_16, D_36, B_32, R_12 },
294 	[INSTR_SS_RRRDRD2]   = { R_8, D_20, B_16, R_12, D_36, B_32 },
295 	[INSTR_SS_RRRDRD3]   = { R_8, R_12, D_20, B_16, D_36, B_32 },
296 	[INSTR_S_00]	     = { 0, 0, 0, 0, 0, 0 },
297 	[INSTR_S_RD]	     = { D_20, B_16, 0, 0, 0, 0 },
298 	[INSTR_VRI_V0IU]     = { V_8, I16_16, U4_32, 0, 0, 0 },
299 	[INSTR_VRI_V0U]	     = { V_8, U16_16, 0, 0, 0, 0 },
300 	[INSTR_VRI_V0UU2]    = { V_8, U16_16, U4_32, 0, 0, 0 },
301 	[INSTR_VRI_V0UUU]    = { V_8, U8_16, U8_24, U4_32, 0, 0 },
302 	[INSTR_VRI_VR0UU]    = { V_8, R_12, U8_28, U4_24, 0, 0 },
303 	[INSTR_VRI_VVUU]     = { V_8, V_12, U16_16, U4_32, 0, 0 },
304 	[INSTR_VRI_VVUUU]    = { V_8, V_12, U12_16, U4_32, U4_28, 0 },
305 	[INSTR_VRI_VVUUU2]   = { V_8, V_12, U8_28, U8_16, U4_24, 0 },
306 	[INSTR_VRI_VVV0U]    = { V_8, V_12, V_16, U8_24, 0, 0 },
307 	[INSTR_VRI_VVV0UU]   = { V_8, V_12, V_16, U8_24, U4_32, 0 },
308 	[INSTR_VRI_VVV0UU2]  = { V_8, V_12, V_16, U8_28, U4_24, 0 },
309 	[INSTR_VRR_0V]	     = { V_12, 0, 0, 0, 0, 0 },
310 	[INSTR_VRR_0VV0U]    = { V_12, V_16, U4_24, 0, 0, 0 },
311 	[INSTR_VRR_RV0UU]    = { R_8, V_12, U4_24, U4_28, 0, 0 },
312 	[INSTR_VRR_VRR]	     = { V_8, R_12, R_16, 0, 0, 0 },
313 	[INSTR_VRR_VV]	     = { V_8, V_12, 0, 0, 0, 0 },
314 	[INSTR_VRR_VV0U]     = { V_8, V_12, U4_32, 0, 0, 0 },
315 	[INSTR_VRR_VV0U0U]   = { V_8, V_12, U4_32, U4_24, 0, 0 },
316 	[INSTR_VRR_VV0U2]    = { V_8, V_12, U4_24, 0, 0, 0 },
317 	[INSTR_VRR_VV0UU2]   = { V_8, V_12, U4_32, U4_28, 0, 0 },
318 	[INSTR_VRR_VV0UUU]   = { V_8, V_12, U4_32, U4_28, U4_24, 0 },
319 	[INSTR_VRR_VVV]	     = { V_8, V_12, V_16, 0, 0, 0 },
320 	[INSTR_VRR_VVV0U]    = { V_8, V_12, V_16, U4_32, 0, 0 },
321 	[INSTR_VRR_VVV0U0]   = { V_8, V_12, V_16, U4_24, 0, 0 },
322 	[INSTR_VRR_VVV0U0U]  = { V_8, V_12, V_16, U4_32, U4_24, 0 },
323 	[INSTR_VRR_VVV0UU]   = { V_8, V_12, V_16, U4_32, U4_28, 0 },
324 	[INSTR_VRR_VVV0UUU]  = { V_8, V_12, V_16, U4_32, U4_28, U4_24 },
325 	[INSTR_VRR_VVV0V]    = { V_8, V_12, V_16, V_32, 0, 0 },
326 	[INSTR_VRR_VVVU0UV]  = { V_8, V_12, V_16, V_32, U4_28, U4_20 },
327 	[INSTR_VRR_VVVU0V]   = { V_8, V_12, V_16, V_32, U4_20, 0 },
328 	[INSTR_VRR_VVVUU0V]  = { V_8, V_12, V_16, V_32, U4_20, U4_24 },
329 	[INSTR_VRS_RRDV]     = { V_32, R_12, D_20, B_16, 0, 0 },
330 	[INSTR_VRS_RVRDU]    = { R_8, V_12, D_20, B_16, U4_32, 0 },
331 	[INSTR_VRS_VRRD]     = { V_8, R_12, D_20, B_16, 0, 0 },
332 	[INSTR_VRS_VRRDU]    = { V_8, R_12, D_20, B_16, U4_32, 0 },
333 	[INSTR_VRS_VVRDU]    = { V_8, V_12, D_20, B_16, U4_32, 0 },
334 	[INSTR_VRV_VVXRDU]   = { V_8, D_20, VX_12, B_16, U4_32, 0 },
335 	[INSTR_VRX_VRRDU]    = { V_8, D_20, X_12, B_16, U4_32, 0 },
336 	[INSTR_VRX_VV]	     = { V_8, V_12, 0, 0, 0, 0 },
337 	[INSTR_VSI_URDV]     = { V_32, D_20, B_16, U8_8, 0, 0 },
338 };
339 
340 static char long_insn_name[][7] = LONG_INSN_INITIALIZER;
341 static struct s390_insn opcode[] = OPCODE_TABLE_INITIALIZER;
342 static struct s390_opcode_offset opcode_offset[] = OPCODE_OFFSET_INITIALIZER;
343 
344 /* Extracts an operand value from an instruction.  */
345 static unsigned int extract_operand(unsigned char *code,
346 				    const struct s390_operand *operand)
347 {
348 	unsigned char *cp;
349 	unsigned int val;
350 	int bits;
351 
352 	/* Extract fragments of the operand byte for byte.  */
353 	cp = code + operand->shift / 8;
354 	bits = (operand->shift & 7) + operand->bits;
355 	val = 0;
356 	do {
357 		val <<= 8;
358 		val |= (unsigned int) *cp++;
359 		bits -= 8;
360 	} while (bits > 0);
361 	val >>= -bits;
362 	val &= ((1U << (operand->bits - 1)) << 1) - 1;
363 
364 	/* Check for special long displacement case.  */
365 	if (operand->bits == 20 && operand->shift == 20)
366 		val = (val & 0xff) << 12 | (val & 0xfff00) >> 8;
367 
368 	/* Check for register extensions bits for vector registers. */
369 	if (operand->flags & OPERAND_VR) {
370 		if (operand->shift == 8)
371 			val |= (code[4] & 8) << 1;
372 		else if (operand->shift == 12)
373 			val |= (code[4] & 4) << 2;
374 		else if (operand->shift == 16)
375 			val |= (code[4] & 2) << 3;
376 		else if (operand->shift == 32)
377 			val |= (code[4] & 1) << 4;
378 	}
379 
380 	/* Sign extend value if the operand is signed or pc relative.  */
381 	if ((operand->flags & (OPERAND_SIGNED | OPERAND_PCREL)) &&
382 	    (val & (1U << (operand->bits - 1))))
383 		val |= (-1U << (operand->bits - 1)) << 1;
384 
385 	/* Double value if the operand is pc relative.	*/
386 	if (operand->flags & OPERAND_PCREL)
387 		val <<= 1;
388 
389 	/* Length x in an instructions has real length x + 1.  */
390 	if (operand->flags & OPERAND_LENGTH)
391 		val++;
392 	return val;
393 }
394 
395 struct s390_insn *find_insn(unsigned char *code)
396 {
397 	struct s390_opcode_offset *entry;
398 	struct s390_insn *insn;
399 	unsigned char opfrag;
400 	int i;
401 
402 	/* Search the opcode offset table to find an entry which
403 	 * matches the beginning of the opcode. If there is no match
404 	 * the last entry will be used, which is the default entry for
405 	 * unknown instructions as well as 1-byte opcode instructions.
406 	 */
407 	for (i = 0; i < ARRAY_SIZE(opcode_offset); i++) {
408 		entry = &opcode_offset[i];
409 		if (entry->opcode == code[0])
410 			break;
411 	}
412 
413 	opfrag = *(code + entry->byte) & entry->mask;
414 
415 	insn = &opcode[entry->offset];
416 	for (i = 0; i < entry->count; i++) {
417 		if (insn->opfrag == opfrag)
418 			return insn;
419 		insn++;
420 	}
421 	return NULL;
422 }
423 
424 static int print_insn(char *buffer, unsigned char *code, unsigned long addr)
425 {
426 	struct s390_insn *insn;
427 	const unsigned char *ops;
428 	const struct s390_operand *operand;
429 	unsigned int value;
430 	char separator;
431 	char *ptr;
432 	int i;
433 
434 	ptr = buffer;
435 	insn = find_insn(code);
436 	if (insn) {
437 		if (insn->zero == 0)
438 			ptr += sprintf(ptr, "%.7s\t",
439 				       long_insn_name[insn->offset]);
440 		else
441 			ptr += sprintf(ptr, "%.5s\t", insn->name);
442 		/* Extract the operands. */
443 		separator = 0;
444 		for (ops = formats[insn->format], i = 0;
445 		     *ops != 0 && i < 6; ops++, i++) {
446 			operand = operands + *ops;
447 			value = extract_operand(code, operand);
448 			if ((operand->flags & OPERAND_INDEX)  && value == 0)
449 				continue;
450 			if ((operand->flags & OPERAND_BASE) &&
451 			    value == 0 && separator == '(') {
452 				separator = ',';
453 				continue;
454 			}
455 			if (separator)
456 				ptr += sprintf(ptr, "%c", separator);
457 			if (operand->flags & OPERAND_GPR)
458 				ptr += sprintf(ptr, "%%r%i", value);
459 			else if (operand->flags & OPERAND_FPR)
460 				ptr += sprintf(ptr, "%%f%i", value);
461 			else if (operand->flags & OPERAND_AR)
462 				ptr += sprintf(ptr, "%%a%i", value);
463 			else if (operand->flags & OPERAND_CR)
464 				ptr += sprintf(ptr, "%%c%i", value);
465 			else if (operand->flags & OPERAND_VR)
466 				ptr += sprintf(ptr, "%%v%i", value);
467 			else if (operand->flags & OPERAND_PCREL) {
468 				void *pcrel = (void *)((int)value + addr);
469 
470 				ptr += sprintf(ptr, "%px", pcrel);
471 			} else if (operand->flags & OPERAND_SIGNED)
472 				ptr += sprintf(ptr, "%i", value);
473 			else
474 				ptr += sprintf(ptr, "%u", value);
475 			if (operand->flags & OPERAND_DISP)
476 				separator = '(';
477 			else if (operand->flags & OPERAND_BASE) {
478 				ptr += sprintf(ptr, ")");
479 				separator = ',';
480 			} else
481 				separator = ',';
482 		}
483 	} else
484 		ptr += sprintf(ptr, "unknown");
485 	return (int) (ptr - buffer);
486 }
487 
488 static int copy_from_regs(struct pt_regs *regs, void *dst, void *src, int len)
489 {
490 	if (user_mode(regs)) {
491 		if (copy_from_user(dst, (char __user *)src, len))
492 			return -EFAULT;
493 	} else {
494 		if (copy_from_kernel_nofault(dst, src, len))
495 			return -EFAULT;
496 	}
497 	return 0;
498 }
499 
500 void show_code(struct pt_regs *regs)
501 {
502 	char *mode = user_mode(regs) ? "User" : "Krnl";
503 	unsigned char code[64];
504 	char buffer[128], *ptr;
505 	unsigned long addr;
506 	int start, end, opsize, hops, i;
507 
508 	/* Get a snapshot of the 64 bytes surrounding the fault address. */
509 	for (start = 32; start && regs->psw.addr >= 34 - start; start -= 2) {
510 		addr = regs->psw.addr - 34 + start;
511 		if (copy_from_regs(regs, code + start - 2, (void *)addr, 2))
512 			break;
513 	}
514 	for (end = 32; end < 64; end += 2) {
515 		addr = regs->psw.addr + end - 32;
516 		if (copy_from_regs(regs, code + end, (void *)addr, 2))
517 			break;
518 	}
519 	/* Code snapshot useable ? */
520 	if ((regs->psw.addr & 1) || start >= end) {
521 		printk("%s Code: Bad PSW.\n", mode);
522 		return;
523 	}
524 	/* Find a starting point for the disassembly. */
525 	while (start < 32) {
526 		for (i = 0, hops = 0; start + i < 32 && hops < 3; hops++) {
527 			if (!find_insn(code + start + i))
528 				break;
529 			i += insn_length(code[start + i]);
530 		}
531 		if (start + i == 32)
532 			/* Looks good, sequence ends at PSW. */
533 			break;
534 		start += 2;
535 	}
536 	/* Decode the instructions. */
537 	ptr = buffer;
538 	ptr += sprintf(ptr, "%s Code:", mode);
539 	hops = 0;
540 	while (start < end && hops < 8) {
541 		opsize = insn_length(code[start]);
542 		if  (start + opsize == 32)
543 			*ptr++ = '#';
544 		else if (start == 32)
545 			*ptr++ = '>';
546 		else
547 			*ptr++ = ' ';
548 		addr = regs->psw.addr + start - 32;
549 		ptr += sprintf(ptr, "%px: ", (void *)addr);
550 		if (start + opsize >= end)
551 			break;
552 		for (i = 0; i < opsize; i++)
553 			ptr += sprintf(ptr, "%02x", code[start + i]);
554 		*ptr++ = '\t';
555 		if (i < 6)
556 			*ptr++ = '\t';
557 		ptr += print_insn(ptr, code + start, addr);
558 		start += opsize;
559 		pr_cont("%s", buffer);
560 		ptr = buffer;
561 		ptr += sprintf(ptr, "\n          ");
562 		hops++;
563 	}
564 	pr_cont("\n");
565 }
566 
567 void print_fn_code(unsigned char *code, unsigned long len)
568 {
569 	char buffer[128], *ptr;
570 	int opsize, i;
571 
572 	while (len) {
573 		ptr = buffer;
574 		opsize = insn_length(*code);
575 		if (opsize > len)
576 			break;
577 		ptr += sprintf(ptr, "%px: ", code);
578 		for (i = 0; i < opsize; i++)
579 			ptr += sprintf(ptr, "%02x", code[i]);
580 		*ptr++ = '\t';
581 		if (i < 4)
582 			*ptr++ = '\t';
583 		ptr += print_insn(ptr, code, (unsigned long) code);
584 		*ptr++ = '\n';
585 		*ptr++ = 0;
586 		printk("%s", buffer);
587 		code += opsize;
588 		len -= opsize;
589 	}
590 }
591