1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2000 Hewlett-Packard Co
4 * Copyright (C) 2000 David Mosberger-Tang <davidm@hpl.hp.com>
5 *
6 * Generic IA-64 unwind info decoder.
7 *
8 * This file is used both by the Linux kernel and objdump. Please keep
9 * the two copies of this file in sync.
10 *
11 * You need to customize the decoder by defining the following
12 * macros/constants before including this file:
13 *
14 * Types:
15 * unw_word Unsigned integer type with at least 64 bits
16 *
17 * Register names:
18 * UNW_REG_BSP
19 * UNW_REG_BSPSTORE
20 * UNW_REG_FPSR
21 * UNW_REG_LC
22 * UNW_REG_PFS
23 * UNW_REG_PR
24 * UNW_REG_RNAT
25 * UNW_REG_PSP
26 * UNW_REG_RP
27 * UNW_REG_UNAT
28 *
29 * Decoder action macros:
30 * UNW_DEC_BAD_CODE(code)
31 * UNW_DEC_ABI(fmt,abi,context,arg)
32 * UNW_DEC_BR_GR(fmt,brmask,gr,arg)
33 * UNW_DEC_BR_MEM(fmt,brmask,arg)
34 * UNW_DEC_COPY_STATE(fmt,label,arg)
35 * UNW_DEC_EPILOGUE(fmt,t,ecount,arg)
36 * UNW_DEC_FRGR_MEM(fmt,grmask,frmask,arg)
37 * UNW_DEC_FR_MEM(fmt,frmask,arg)
38 * UNW_DEC_GR_GR(fmt,grmask,gr,arg)
39 * UNW_DEC_GR_MEM(fmt,grmask,arg)
40 * UNW_DEC_LABEL_STATE(fmt,label,arg)
41 * UNW_DEC_MEM_STACK_F(fmt,t,size,arg)
42 * UNW_DEC_MEM_STACK_V(fmt,t,arg)
43 * UNW_DEC_PRIUNAT_GR(fmt,r,arg)
44 * UNW_DEC_PRIUNAT_WHEN_GR(fmt,t,arg)
45 * UNW_DEC_PRIUNAT_WHEN_MEM(fmt,t,arg)
46 * UNW_DEC_PRIUNAT_WHEN_PSPREL(fmt,pspoff,arg)
47 * UNW_DEC_PRIUNAT_WHEN_SPREL(fmt,spoff,arg)
48 * UNW_DEC_PROLOGUE(fmt,body,rlen,arg)
49 * UNW_DEC_PROLOGUE_GR(fmt,rlen,mask,grsave,arg)
50 * UNW_DEC_REG_PSPREL(fmt,reg,pspoff,arg)
51 * UNW_DEC_REG_REG(fmt,src,dst,arg)
52 * UNW_DEC_REG_SPREL(fmt,reg,spoff,arg)
53 * UNW_DEC_REG_WHEN(fmt,reg,t,arg)
54 * UNW_DEC_RESTORE(fmt,t,abreg,arg)
55 * UNW_DEC_RESTORE_P(fmt,qp,t,abreg,arg)
56 * UNW_DEC_SPILL_BASE(fmt,pspoff,arg)
57 * UNW_DEC_SPILL_MASK(fmt,imaskp,arg)
58 * UNW_DEC_SPILL_PSPREL(fmt,t,abreg,pspoff,arg)
59 * UNW_DEC_SPILL_PSPREL_P(fmt,qp,t,abreg,pspoff,arg)
60 * UNW_DEC_SPILL_REG(fmt,t,abreg,x,ytreg,arg)
61 * UNW_DEC_SPILL_REG_P(fmt,qp,t,abreg,x,ytreg,arg)
62 * UNW_DEC_SPILL_SPREL(fmt,t,abreg,spoff,arg)
63 * UNW_DEC_SPILL_SPREL_P(fmt,qp,t,abreg,pspoff,arg)
64 */
65
66 static unw_word
unw_decode_uleb128(unsigned char ** dpp)67 unw_decode_uleb128 (unsigned char **dpp)
68 {
69 unsigned shift = 0;
70 unw_word byte, result = 0;
71 unsigned char *bp = *dpp;
72
73 while (1)
74 {
75 byte = *bp++;
76 result |= (byte & 0x7f) << shift;
77 if ((byte & 0x80) == 0)
78 break;
79 shift += 7;
80 }
81 *dpp = bp;
82 return result;
83 }
84
85 static unsigned char *
unw_decode_x1(unsigned char * dp,unsigned char code,void * arg)86 unw_decode_x1 (unsigned char *dp, unsigned char code, void *arg)
87 {
88 unsigned char byte1, abreg;
89 unw_word t, off;
90
91 byte1 = *dp++;
92 t = unw_decode_uleb128 (&dp);
93 off = unw_decode_uleb128 (&dp);
94 abreg = (byte1 & 0x7f);
95 if (byte1 & 0x80)
96 UNW_DEC_SPILL_SPREL(X1, t, abreg, off, arg);
97 else
98 UNW_DEC_SPILL_PSPREL(X1, t, abreg, off, arg);
99 return dp;
100 }
101
102 static unsigned char *
unw_decode_x2(unsigned char * dp,unsigned char code,void * arg)103 unw_decode_x2 (unsigned char *dp, unsigned char code, void *arg)
104 {
105 unsigned char byte1, byte2, abreg, x, ytreg;
106 unw_word t;
107
108 byte1 = *dp++; byte2 = *dp++;
109 t = unw_decode_uleb128 (&dp);
110 abreg = (byte1 & 0x7f);
111 ytreg = byte2;
112 x = (byte1 >> 7) & 1;
113 if ((byte1 & 0x80) == 0 && ytreg == 0)
114 UNW_DEC_RESTORE(X2, t, abreg, arg);
115 else
116 UNW_DEC_SPILL_REG(X2, t, abreg, x, ytreg, arg);
117 return dp;
118 }
119
120 static unsigned char *
unw_decode_x3(unsigned char * dp,unsigned char code,void * arg)121 unw_decode_x3 (unsigned char *dp, unsigned char code, void *arg)
122 {
123 unsigned char byte1, byte2, abreg, qp;
124 unw_word t, off;
125
126 byte1 = *dp++; byte2 = *dp++;
127 t = unw_decode_uleb128 (&dp);
128 off = unw_decode_uleb128 (&dp);
129
130 qp = (byte1 & 0x3f);
131 abreg = (byte2 & 0x7f);
132
133 if (byte1 & 0x80)
134 UNW_DEC_SPILL_SPREL_P(X3, qp, t, abreg, off, arg);
135 else
136 UNW_DEC_SPILL_PSPREL_P(X3, qp, t, abreg, off, arg);
137 return dp;
138 }
139
140 static unsigned char *
unw_decode_x4(unsigned char * dp,unsigned char code,void * arg)141 unw_decode_x4 (unsigned char *dp, unsigned char code, void *arg)
142 {
143 unsigned char byte1, byte2, byte3, qp, abreg, x, ytreg;
144 unw_word t;
145
146 byte1 = *dp++; byte2 = *dp++; byte3 = *dp++;
147 t = unw_decode_uleb128 (&dp);
148
149 qp = (byte1 & 0x3f);
150 abreg = (byte2 & 0x7f);
151 x = (byte2 >> 7) & 1;
152 ytreg = byte3;
153
154 if ((byte2 & 0x80) == 0 && byte3 == 0)
155 UNW_DEC_RESTORE_P(X4, qp, t, abreg, arg);
156 else
157 UNW_DEC_SPILL_REG_P(X4, qp, t, abreg, x, ytreg, arg);
158 return dp;
159 }
160
161 static unsigned char *
unw_decode_r1(unsigned char * dp,unsigned char code,void * arg)162 unw_decode_r1 (unsigned char *dp, unsigned char code, void *arg)
163 {
164 int body = (code & 0x20) != 0;
165 unw_word rlen;
166
167 rlen = (code & 0x1f);
168 UNW_DEC_PROLOGUE(R1, body, rlen, arg);
169 return dp;
170 }
171
172 static unsigned char *
unw_decode_r2(unsigned char * dp,unsigned char code,void * arg)173 unw_decode_r2 (unsigned char *dp, unsigned char code, void *arg)
174 {
175 unsigned char byte1, mask, grsave;
176 unw_word rlen;
177
178 byte1 = *dp++;
179
180 mask = ((code & 0x7) << 1) | ((byte1 >> 7) & 1);
181 grsave = (byte1 & 0x7f);
182 rlen = unw_decode_uleb128 (&dp);
183 UNW_DEC_PROLOGUE_GR(R2, rlen, mask, grsave, arg);
184 return dp;
185 }
186
187 static unsigned char *
unw_decode_r3(unsigned char * dp,unsigned char code,void * arg)188 unw_decode_r3 (unsigned char *dp, unsigned char code, void *arg)
189 {
190 unw_word rlen;
191
192 rlen = unw_decode_uleb128 (&dp);
193 UNW_DEC_PROLOGUE(R3, ((code & 0x3) == 1), rlen, arg);
194 return dp;
195 }
196
197 static unsigned char *
unw_decode_p1(unsigned char * dp,unsigned char code,void * arg)198 unw_decode_p1 (unsigned char *dp, unsigned char code, void *arg)
199 {
200 unsigned char brmask = (code & 0x1f);
201
202 UNW_DEC_BR_MEM(P1, brmask, arg);
203 return dp;
204 }
205
206 static unsigned char *
unw_decode_p2_p5(unsigned char * dp,unsigned char code,void * arg)207 unw_decode_p2_p5 (unsigned char *dp, unsigned char code, void *arg)
208 {
209 if ((code & 0x10) == 0)
210 {
211 unsigned char byte1 = *dp++;
212
213 UNW_DEC_BR_GR(P2, ((code & 0xf) << 1) | ((byte1 >> 7) & 1),
214 (byte1 & 0x7f), arg);
215 }
216 else if ((code & 0x08) == 0)
217 {
218 unsigned char byte1 = *dp++, r, dst;
219
220 r = ((code & 0x7) << 1) | ((byte1 >> 7) & 1);
221 dst = (byte1 & 0x7f);
222 switch (r)
223 {
224 case 0: UNW_DEC_REG_GR(P3, UNW_REG_PSP, dst, arg); break;
225 case 1: UNW_DEC_REG_GR(P3, UNW_REG_RP, dst, arg); break;
226 case 2: UNW_DEC_REG_GR(P3, UNW_REG_PFS, dst, arg); break;
227 case 3: UNW_DEC_REG_GR(P3, UNW_REG_PR, dst, arg); break;
228 case 4: UNW_DEC_REG_GR(P3, UNW_REG_UNAT, dst, arg); break;
229 case 5: UNW_DEC_REG_GR(P3, UNW_REG_LC, dst, arg); break;
230 case 6: UNW_DEC_RP_BR(P3, dst, arg); break;
231 case 7: UNW_DEC_REG_GR(P3, UNW_REG_RNAT, dst, arg); break;
232 case 8: UNW_DEC_REG_GR(P3, UNW_REG_BSP, dst, arg); break;
233 case 9: UNW_DEC_REG_GR(P3, UNW_REG_BSPSTORE, dst, arg); break;
234 case 10: UNW_DEC_REG_GR(P3, UNW_REG_FPSR, dst, arg); break;
235 case 11: UNW_DEC_PRIUNAT_GR(P3, dst, arg); break;
236 default: UNW_DEC_BAD_CODE(r); break;
237 }
238 }
239 else if ((code & 0x7) == 0)
240 UNW_DEC_SPILL_MASK(P4, dp, arg);
241 else if ((code & 0x7) == 1)
242 {
243 unw_word grmask, frmask, byte1, byte2, byte3;
244
245 byte1 = *dp++; byte2 = *dp++; byte3 = *dp++;
246 grmask = ((byte1 >> 4) & 0xf);
247 frmask = ((byte1 & 0xf) << 16) | (byte2 << 8) | byte3;
248 UNW_DEC_FRGR_MEM(P5, grmask, frmask, arg);
249 }
250 else
251 UNW_DEC_BAD_CODE(code);
252 return dp;
253 }
254
255 static unsigned char *
unw_decode_p6(unsigned char * dp,unsigned char code,void * arg)256 unw_decode_p6 (unsigned char *dp, unsigned char code, void *arg)
257 {
258 int gregs = (code & 0x10) != 0;
259 unsigned char mask = (code & 0x0f);
260
261 if (gregs)
262 UNW_DEC_GR_MEM(P6, mask, arg);
263 else
264 UNW_DEC_FR_MEM(P6, mask, arg);
265 return dp;
266 }
267
268 static unsigned char *
unw_decode_p7_p10(unsigned char * dp,unsigned char code,void * arg)269 unw_decode_p7_p10 (unsigned char *dp, unsigned char code, void *arg)
270 {
271 unsigned char r, byte1, byte2;
272 unw_word t, size;
273
274 if ((code & 0x10) == 0)
275 {
276 r = (code & 0xf);
277 t = unw_decode_uleb128 (&dp);
278 switch (r)
279 {
280 case 0:
281 size = unw_decode_uleb128 (&dp);
282 UNW_DEC_MEM_STACK_F(P7, t, size, arg);
283 break;
284
285 case 1: UNW_DEC_MEM_STACK_V(P7, t, arg); break;
286 case 2: UNW_DEC_SPILL_BASE(P7, t, arg); break;
287 case 3: UNW_DEC_REG_SPREL(P7, UNW_REG_PSP, t, arg); break;
288 case 4: UNW_DEC_REG_WHEN(P7, UNW_REG_RP, t, arg); break;
289 case 5: UNW_DEC_REG_PSPREL(P7, UNW_REG_RP, t, arg); break;
290 case 6: UNW_DEC_REG_WHEN(P7, UNW_REG_PFS, t, arg); break;
291 case 7: UNW_DEC_REG_PSPREL(P7, UNW_REG_PFS, t, arg); break;
292 case 8: UNW_DEC_REG_WHEN(P7, UNW_REG_PR, t, arg); break;
293 case 9: UNW_DEC_REG_PSPREL(P7, UNW_REG_PR, t, arg); break;
294 case 10: UNW_DEC_REG_WHEN(P7, UNW_REG_LC, t, arg); break;
295 case 11: UNW_DEC_REG_PSPREL(P7, UNW_REG_LC, t, arg); break;
296 case 12: UNW_DEC_REG_WHEN(P7, UNW_REG_UNAT, t, arg); break;
297 case 13: UNW_DEC_REG_PSPREL(P7, UNW_REG_UNAT, t, arg); break;
298 case 14: UNW_DEC_REG_WHEN(P7, UNW_REG_FPSR, t, arg); break;
299 case 15: UNW_DEC_REG_PSPREL(P7, UNW_REG_FPSR, t, arg); break;
300 default: UNW_DEC_BAD_CODE(r); break;
301 }
302 }
303 else
304 {
305 switch (code & 0xf)
306 {
307 case 0x0: /* p8 */
308 {
309 r = *dp++;
310 t = unw_decode_uleb128 (&dp);
311 switch (r)
312 {
313 case 1: UNW_DEC_REG_SPREL(P8, UNW_REG_RP, t, arg); break;
314 case 2: UNW_DEC_REG_SPREL(P8, UNW_REG_PFS, t, arg); break;
315 case 3: UNW_DEC_REG_SPREL(P8, UNW_REG_PR, t, arg); break;
316 case 4: UNW_DEC_REG_SPREL(P8, UNW_REG_LC, t, arg); break;
317 case 5: UNW_DEC_REG_SPREL(P8, UNW_REG_UNAT, t, arg); break;
318 case 6: UNW_DEC_REG_SPREL(P8, UNW_REG_FPSR, t, arg); break;
319 case 7: UNW_DEC_REG_WHEN(P8, UNW_REG_BSP, t, arg); break;
320 case 8: UNW_DEC_REG_PSPREL(P8, UNW_REG_BSP, t, arg); break;
321 case 9: UNW_DEC_REG_SPREL(P8, UNW_REG_BSP, t, arg); break;
322 case 10: UNW_DEC_REG_WHEN(P8, UNW_REG_BSPSTORE, t, arg); break;
323 case 11: UNW_DEC_REG_PSPREL(P8, UNW_REG_BSPSTORE, t, arg); break;
324 case 12: UNW_DEC_REG_SPREL(P8, UNW_REG_BSPSTORE, t, arg); break;
325 case 13: UNW_DEC_REG_WHEN(P8, UNW_REG_RNAT, t, arg); break;
326 case 14: UNW_DEC_REG_PSPREL(P8, UNW_REG_RNAT, t, arg); break;
327 case 15: UNW_DEC_REG_SPREL(P8, UNW_REG_RNAT, t, arg); break;
328 case 16: UNW_DEC_PRIUNAT_WHEN_GR(P8, t, arg); break;
329 case 17: UNW_DEC_PRIUNAT_PSPREL(P8, t, arg); break;
330 case 18: UNW_DEC_PRIUNAT_SPREL(P8, t, arg); break;
331 case 19: UNW_DEC_PRIUNAT_WHEN_MEM(P8, t, arg); break;
332 default: UNW_DEC_BAD_CODE(r); break;
333 }
334 }
335 break;
336
337 case 0x1:
338 byte1 = *dp++; byte2 = *dp++;
339 UNW_DEC_GR_GR(P9, (byte1 & 0xf), (byte2 & 0x7f), arg);
340 break;
341
342 case 0xf: /* p10 */
343 byte1 = *dp++; byte2 = *dp++;
344 UNW_DEC_ABI(P10, byte1, byte2, arg);
345 break;
346
347 case 0x9:
348 return unw_decode_x1 (dp, code, arg);
349
350 case 0xa:
351 return unw_decode_x2 (dp, code, arg);
352
353 case 0xb:
354 return unw_decode_x3 (dp, code, arg);
355
356 case 0xc:
357 return unw_decode_x4 (dp, code, arg);
358
359 default:
360 UNW_DEC_BAD_CODE(code);
361 break;
362 }
363 }
364 return dp;
365 }
366
367 static unsigned char *
unw_decode_b1(unsigned char * dp,unsigned char code,void * arg)368 unw_decode_b1 (unsigned char *dp, unsigned char code, void *arg)
369 {
370 unw_word label = (code & 0x1f);
371
372 if ((code & 0x20) != 0)
373 UNW_DEC_COPY_STATE(B1, label, arg);
374 else
375 UNW_DEC_LABEL_STATE(B1, label, arg);
376 return dp;
377 }
378
379 static unsigned char *
unw_decode_b2(unsigned char * dp,unsigned char code,void * arg)380 unw_decode_b2 (unsigned char *dp, unsigned char code, void *arg)
381 {
382 unw_word t;
383
384 t = unw_decode_uleb128 (&dp);
385 UNW_DEC_EPILOGUE(B2, t, (code & 0x1f), arg);
386 return dp;
387 }
388
389 static unsigned char *
unw_decode_b3_x4(unsigned char * dp,unsigned char code,void * arg)390 unw_decode_b3_x4 (unsigned char *dp, unsigned char code, void *arg)
391 {
392 unw_word t, ecount, label;
393
394 if ((code & 0x10) == 0)
395 {
396 t = unw_decode_uleb128 (&dp);
397 ecount = unw_decode_uleb128 (&dp);
398 UNW_DEC_EPILOGUE(B3, t, ecount, arg);
399 }
400 else if ((code & 0x07) == 0)
401 {
402 label = unw_decode_uleb128 (&dp);
403 if ((code & 0x08) != 0)
404 UNW_DEC_COPY_STATE(B4, label, arg);
405 else
406 UNW_DEC_LABEL_STATE(B4, label, arg);
407 }
408 else
409 switch (code & 0x7)
410 {
411 case 1: return unw_decode_x1 (dp, code, arg);
412 case 2: return unw_decode_x2 (dp, code, arg);
413 case 3: return unw_decode_x3 (dp, code, arg);
414 case 4: return unw_decode_x4 (dp, code, arg);
415 default: UNW_DEC_BAD_CODE(code); break;
416 }
417 return dp;
418 }
419
420 typedef unsigned char *(*unw_decoder) (unsigned char *, unsigned char, void *);
421
422 static unw_decoder unw_decode_table[2][8] =
423 {
424 /* prologue table: */
425 {
426 unw_decode_r1, /* 0 */
427 unw_decode_r1,
428 unw_decode_r2,
429 unw_decode_r3,
430 unw_decode_p1, /* 4 */
431 unw_decode_p2_p5,
432 unw_decode_p6,
433 unw_decode_p7_p10
434 },
435 {
436 unw_decode_r1, /* 0 */
437 unw_decode_r1,
438 unw_decode_r2,
439 unw_decode_r3,
440 unw_decode_b1, /* 4 */
441 unw_decode_b1,
442 unw_decode_b2,
443 unw_decode_b3_x4
444 }
445 };
446
447 /*
448 * Decode one descriptor and return address of next descriptor.
449 */
450 static inline unsigned char *
unw_decode(unsigned char * dp,int inside_body,void * arg)451 unw_decode (unsigned char *dp, int inside_body, void *arg)
452 {
453 unw_decoder decoder;
454 unsigned char code;
455
456 code = *dp++;
457 decoder = unw_decode_table[inside_body][code >> 5];
458 dp = (*decoder) (dp, code, arg);
459 return dp;
460 }
461