1 /* Target-dependent code for OpenBSD/sparc64. 2 3 Copyright (C) 2004-2023 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #include "defs.h" 21 #include "frame.h" 22 #include "frame-unwind.h" 23 #include "gdbcore.h" 24 #include "osabi.h" 25 #include "regcache.h" 26 #include "regset.h" 27 #include "symtab.h" 28 #include "objfiles.h" 29 #include "trad-frame.h" 30 #include "inferior.h" 31 32 #include "obsd-tdep.h" 33 #include "sparc64-tdep.h" 34 #include "solib-svr4.h" 35 #include "bsd-uthread.h" 36 37 /* Older OpenBSD versions used the traditional NetBSD core file 38 format, even for ports that use ELF. These core files don't use 39 multiple register sets. Instead, the general-purpose and 40 floating-point registers are lumped together in a single section. 41 Unlike on NetBSD, OpenBSD uses a different layout for its 42 general-purpose registers than the layout used for ptrace(2). 43 44 Newer OpenBSD versions use ELF core files. Here the register sets 45 match the ptrace(2) layout. */ 46 47 /* From <machine/reg.h>. */ 48 const struct sparc_gregmap sparc64obsd_gregmap = 49 { 50 0 * 8, /* "tstate" */ 51 1 * 8, /* %pc */ 52 2 * 8, /* %npc */ 53 3 * 8, /* %y */ 54 -1, /* %fprs */ 55 -1, 56 5 * 8, /* %g1 */ 57 20 * 8, /* %l0 */ 58 4 /* sizeof (%y) */ 59 }; 60 61 const struct sparc_gregmap sparc64obsd_core_gregmap = 62 { 63 0 * 8, /* "tstate" */ 64 1 * 8, /* %pc */ 65 2 * 8, /* %npc */ 66 3 * 8, /* %y */ 67 -1, /* %fprs */ 68 -1, 69 7 * 8, /* %g1 */ 70 22 * 8, /* %l0 */ 71 4 /* sizeof (%y) */ 72 }; 73 74 static void 75 sparc64obsd_supply_gregset (const struct regset *regset, 76 struct regcache *regcache, 77 int regnum, const void *gregs, size_t len) 78 { 79 const void *fpregs = (char *)gregs + 288; 80 81 if (len < 832) 82 { 83 sparc64_supply_gregset (&sparc64obsd_gregmap, regcache, regnum, gregs); 84 return; 85 } 86 87 sparc64_supply_gregset (&sparc64obsd_core_gregmap, regcache, regnum, gregs); 88 sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs); 89 } 90 91 static void 92 sparc64obsd_supply_fpregset (const struct regset *regset, 93 struct regcache *regcache, 94 int regnum, const void *fpregs, size_t len) 95 { 96 sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs); 97 } 98 99 100 /* Signal trampolines. */ 101 102 /* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page 103 in virtual memory. The randomness makes it somewhat tricky to 104 detect it, but fortunately we can rely on the fact that the start 105 of the sigtramp routine is page-aligned. We recognize the 106 trampoline by looking for the code that invokes the sigreturn 107 system call. The offset where we can find that code varies from 108 release to release. 109 110 By the way, the mapping mentioned above is read-only, so you cannot 111 place a breakpoint in the signal trampoline. */ 112 113 /* Default page size. */ 114 static const int sparc64obsd_page_size = 8192; 115 116 /* Offset for sigreturn(2). */ 117 static const int sparc64obsd_sigreturn_offset[] = { 118 0xf0, /* OpenBSD 3.8 */ 119 0xec, /* OpenBSD 3.6 */ 120 0xe8, /* OpenBSD 3.2 */ 121 -1 122 }; 123 124 static int 125 sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, const char *name) 126 { 127 CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1)); 128 unsigned long insn; 129 const int *offset; 130 131 if (name) 132 return 0; 133 134 for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++) 135 { 136 /* Check for "restore %g0, SYS_sigreturn, %g1". */ 137 insn = sparc_fetch_instruction (start_pc + *offset); 138 if (insn != 0x83e82067) 139 continue; 140 141 /* Check for "t ST_SYSCALL". */ 142 insn = sparc_fetch_instruction (start_pc + *offset + 8); 143 if (insn != 0x91d02000) 144 continue; 145 146 return 1; 147 } 148 149 return 0; 150 } 151 152 static struct sparc_frame_cache * 153 sparc64obsd_frame_cache (frame_info_ptr this_frame, void **this_cache) 154 { 155 struct sparc_frame_cache *cache; 156 CORE_ADDR addr; 157 158 if (*this_cache) 159 return (struct sparc_frame_cache *) *this_cache; 160 161 cache = sparc_frame_cache (this_frame, this_cache); 162 gdb_assert (cache == *this_cache); 163 164 /* If we couldn't find the frame's function, we're probably dealing 165 with an on-stack signal trampoline. */ 166 if (cache->pc == 0) 167 { 168 cache->pc = get_frame_pc (this_frame); 169 cache->pc &= ~(sparc64obsd_page_size - 1); 170 171 /* Since we couldn't find the frame's function, the cache was 172 initialized under the assumption that we're frameless. */ 173 sparc_record_save_insn (cache); 174 addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM); 175 if (addr & 1) 176 addr += BIAS; 177 cache->base = addr; 178 } 179 180 /* We find the appropriate instance of `struct sigcontext' at a 181 fixed offset in the signal frame. */ 182 addr = cache->base + 128 + 16; 183 cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, this_frame); 184 185 return cache; 186 } 187 188 static void 189 sparc64obsd_frame_this_id (frame_info_ptr this_frame, void **this_cache, 190 struct frame_id *this_id) 191 { 192 struct sparc_frame_cache *cache = 193 sparc64obsd_frame_cache (this_frame, this_cache); 194 195 (*this_id) = frame_id_build (cache->base, cache->pc); 196 } 197 198 static struct value * 199 sparc64obsd_frame_prev_register (frame_info_ptr this_frame, 200 void **this_cache, int regnum) 201 { 202 struct sparc_frame_cache *cache = 203 sparc64obsd_frame_cache (this_frame, this_cache); 204 205 return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); 206 } 207 208 static int 209 sparc64obsd_sigtramp_frame_sniffer (const struct frame_unwind *self, 210 frame_info_ptr this_frame, 211 void **this_cache) 212 { 213 CORE_ADDR pc = get_frame_pc (this_frame); 214 const char *name; 215 216 find_pc_partial_function (pc, &name, NULL, NULL); 217 if (sparc64obsd_pc_in_sigtramp (pc, name)) 218 return 1; 219 220 return 0; 221 } 222 223 static const struct frame_unwind sparc64obsd_frame_unwind = 224 { 225 "sparc64 openbsd sigtramp", 226 SIGTRAMP_FRAME, 227 default_frame_unwind_stop_reason, 228 sparc64obsd_frame_this_id, 229 sparc64obsd_frame_prev_register, 230 NULL, 231 sparc64obsd_sigtramp_frame_sniffer 232 }; 233 234 /* Kernel debugging support. */ 235 236 static struct sparc_frame_cache * 237 sparc64obsd_trapframe_cache (frame_info_ptr this_frame, void **this_cache) 238 { 239 struct sparc_frame_cache *cache; 240 CORE_ADDR sp, trapframe_addr; 241 int regnum; 242 243 if (*this_cache) 244 return (struct sparc_frame_cache *) *this_cache; 245 246 cache = sparc_frame_cache (this_frame, this_cache); 247 gdb_assert (cache == *this_cache); 248 249 sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM); 250 trapframe_addr = sp + BIAS + 176; 251 252 cache->saved_regs = trad_frame_alloc_saved_regs (this_frame); 253 254 cache->saved_regs[SPARC64_STATE_REGNUM].set_addr (trapframe_addr); 255 cache->saved_regs[SPARC64_PC_REGNUM].set_addr (trapframe_addr + 8); 256 cache->saved_regs[SPARC64_NPC_REGNUM].set_addr (trapframe_addr + 16); 257 258 for (regnum = SPARC_G0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++) 259 cache->saved_regs[regnum].set_addr (trapframe_addr + 48 260 + (regnum - SPARC_G0_REGNUM) * 8); 261 262 return cache; 263 } 264 265 static void 266 sparc64obsd_trapframe_this_id (frame_info_ptr this_frame, 267 void **this_cache, struct frame_id *this_id) 268 { 269 struct sparc_frame_cache *cache = 270 sparc64obsd_trapframe_cache (this_frame, this_cache); 271 272 (*this_id) = frame_id_build (cache->base, cache->pc); 273 } 274 275 static struct value * 276 sparc64obsd_trapframe_prev_register (frame_info_ptr this_frame, 277 void **this_cache, int regnum) 278 { 279 struct sparc_frame_cache *cache = 280 sparc64obsd_trapframe_cache (this_frame, this_cache); 281 282 return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); 283 } 284 285 static int 286 sparc64obsd_trapframe_sniffer (const struct frame_unwind *self, 287 frame_info_ptr this_frame, 288 void **this_cache) 289 { 290 CORE_ADDR pc; 291 ULONGEST pstate; 292 const char *name; 293 294 /* Check whether we are in privileged mode, and bail out if we're not. */ 295 pstate = get_frame_register_unsigned (this_frame, SPARC64_PSTATE_REGNUM); 296 if ((pstate & SPARC64_PSTATE_PRIV) == 0) 297 return 0; 298 299 pc = get_frame_address_in_block (this_frame); 300 find_pc_partial_function (pc, &name, NULL, NULL); 301 if (name && strcmp (name, "Lslowtrap_reenter") == 0) 302 return 1; 303 304 return 0; 305 } 306 307 static const struct frame_unwind sparc64obsd_trapframe_unwind = 308 { 309 "sparc64 openbsd trap", 310 NORMAL_FRAME, 311 default_frame_unwind_stop_reason, 312 sparc64obsd_trapframe_this_id, 313 sparc64obsd_trapframe_prev_register, 314 NULL, 315 sparc64obsd_trapframe_sniffer 316 }; 317 318 319 /* Threads support. */ 320 321 /* Offset wthin the thread structure where we can find %fp and %i7. */ 322 #define SPARC64OBSD_UTHREAD_FP_OFFSET 232 323 #define SPARC64OBSD_UTHREAD_PC_OFFSET 240 324 325 static void 326 sparc64obsd_supply_uthread (struct regcache *regcache, 327 int regnum, CORE_ADDR addr) 328 { 329 struct gdbarch *gdbarch = regcache->arch (); 330 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 331 CORE_ADDR fp, fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET; 332 gdb_byte buf[8]; 333 334 /* This function calls functions that depend on the global current thread. */ 335 gdb_assert (regcache->ptid () == inferior_ptid); 336 337 gdb_assert (regnum >= -1); 338 339 fp = read_memory_unsigned_integer (fp_addr, 8, byte_order); 340 if (regnum == SPARC_SP_REGNUM || regnum == -1) 341 { 342 store_unsigned_integer (buf, 8, byte_order, fp); 343 regcache->raw_supply (SPARC_SP_REGNUM, buf); 344 345 if (regnum == SPARC_SP_REGNUM) 346 return; 347 } 348 349 if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM 350 || regnum == -1) 351 { 352 CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET; 353 354 i7 = read_memory_unsigned_integer (i7_addr, 8, byte_order); 355 if (regnum == SPARC64_PC_REGNUM || regnum == -1) 356 { 357 store_unsigned_integer (buf, 8, byte_order, i7 + 8); 358 regcache->raw_supply (SPARC64_PC_REGNUM, buf); 359 } 360 if (regnum == SPARC64_NPC_REGNUM || regnum == -1) 361 { 362 store_unsigned_integer (buf, 8, byte_order, i7 + 12); 363 regcache->raw_supply (SPARC64_NPC_REGNUM, buf); 364 } 365 366 if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM) 367 return; 368 } 369 370 sparc_supply_rwindow (regcache, fp, regnum); 371 } 372 373 static void 374 sparc64obsd_collect_uthread(const struct regcache *regcache, 375 int regnum, CORE_ADDR addr) 376 { 377 struct gdbarch *gdbarch = regcache->arch (); 378 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 379 CORE_ADDR sp; 380 gdb_byte buf[8]; 381 382 /* This function calls functions that depend on the global current thread. */ 383 gdb_assert (regcache->ptid () == inferior_ptid); 384 385 gdb_assert (regnum >= -1); 386 387 if (regnum == SPARC_SP_REGNUM || regnum == -1) 388 { 389 CORE_ADDR fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET; 390 391 regcache->raw_collect (SPARC_SP_REGNUM, buf); 392 write_memory (fp_addr,buf, 8); 393 } 394 395 if (regnum == SPARC64_PC_REGNUM || regnum == -1) 396 { 397 CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET; 398 399 regcache->raw_collect (SPARC64_PC_REGNUM, buf); 400 i7 = extract_unsigned_integer (buf, 8, byte_order) - 8; 401 write_memory_unsigned_integer (i7_addr, 8, byte_order, i7); 402 403 if (regnum == SPARC64_PC_REGNUM) 404 return; 405 } 406 407 regcache->raw_collect (SPARC_SP_REGNUM, buf); 408 sp = extract_unsigned_integer (buf, 8, byte_order); 409 sparc_collect_rwindow (regcache, sp, regnum); 410 } 411 412 413 static const struct regset sparc64obsd_gregset = 414 { 415 NULL, sparc64obsd_supply_gregset, NULL 416 }; 417 418 static const struct regset sparc64obsd_fpregset = 419 { 420 NULL, sparc64obsd_supply_fpregset, NULL 421 }; 422 423 static void 424 sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 425 { 426 sparc_gdbarch_tdep *tdep = gdbarch_tdep<sparc_gdbarch_tdep> (gdbarch); 427 428 tdep->gregset = &sparc64obsd_gregset; 429 tdep->sizeof_gregset = 288; 430 tdep->fpregset = &sparc64obsd_fpregset; 431 tdep->sizeof_fpregset = 272; 432 433 /* Make sure we can single-step "new" syscalls. */ 434 tdep->step_trap = sparcnbsd_step_trap; 435 436 frame_unwind_append_unwinder (gdbarch, &sparc64obsd_frame_unwind); 437 frame_unwind_append_unwinder (gdbarch, &sparc64obsd_trapframe_unwind); 438 439 sparc64_init_abi (info, gdbarch); 440 obsd_init_abi (info, gdbarch); 441 442 /* OpenBSD/sparc64 has SVR4-style shared libraries. */ 443 set_solib_svr4_fetch_link_map_offsets 444 (gdbarch, svr4_lp64_fetch_link_map_offsets); 445 set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver); 446 447 /* OpenBSD provides a user-level threads implementation. */ 448 bsd_uthread_set_supply_uthread (gdbarch, sparc64obsd_supply_uthread); 449 bsd_uthread_set_collect_uthread (gdbarch, sparc64obsd_collect_uthread); 450 } 451 452 void _initialize_sparc64obsd_tdep (); 453 void 454 _initialize_sparc64obsd_tdep () 455 { 456 gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, 457 GDB_OSABI_OPENBSD, sparc64obsd_init_abi); 458 } 459