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. */
extract_operand(unsigned char * code,const struct s390_operand * operand)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
find_insn(unsigned char * code)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
print_insn(char * buffer,unsigned char * code,unsigned long addr)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
copy_from_regs(struct pt_regs * regs,void * dst,void * src,int len)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
show_code(struct pt_regs * regs)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
print_fn_code(unsigned char * code,unsigned long len)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