unwind_decoder.c (12329B)
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 66static unw_word 67unw_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 85static unsigned char * 86unw_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 102static unsigned char * 103unw_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 120static unsigned char * 121unw_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 140static unsigned char * 141unw_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 161static unsigned char * 162unw_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 172static unsigned char * 173unw_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 187static unsigned char * 188unw_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 197static unsigned char * 198unw_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 206static unsigned char * 207unw_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 255static unsigned char * 256unw_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 268static unsigned char * 269unw_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 367static unsigned char * 368unw_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 379static unsigned char * 380unw_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 389static unsigned char * 390unw_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 420typedef unsigned char *(*unw_decoder) (unsigned char *, unsigned char, void *); 421 422static 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 */ 450static inline unsigned char * 451unw_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}