1 /* Target-dependent code for OpenBSD/sparc64. 2 3 Copyright (C) 2004-2020 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 31 #include "obsd-tdep.h" 32 #include "sparc64-tdep.h" 33 #include "solib-svr4.h" 34 #include "bsd-uthread.h" 35 36 /* Older OpenBSD versions used the traditional NetBSD core file 37 format, even for ports that use ELF. These core files don't use 38 multiple register sets. Instead, the general-purpose and 39 floating-point registers are lumped together in a single section. 40 Unlike on NetBSD, OpenBSD uses a different layout for its 41 general-purpose registers than the layout used for ptrace(2). 42 43 Newer OpenBSD versions use ELF core files. Here the register sets 44 match the ptrace(2) layout. */ 45 46 /* From <machine/reg.h>. */ 47 const struct sparc_gregmap sparc64obsd_gregmap = 48 { 49 0 * 8, /* "tstate" */ 50 1 * 8, /* %pc */ 51 2 * 8, /* %npc */ 52 3 * 8, /* %y */ 53 -1, /* %fprs */ 54 -1, 55 5 * 8, /* %g1 */ 56 20 * 8, /* %l0 */ 57 4 /* sizeof (%y) */ 58 }; 59 60 const struct sparc_gregmap sparc64obsd_core_gregmap = 61 { 62 0 * 8, /* "tstate" */ 63 1 * 8, /* %pc */ 64 2 * 8, /* %npc */ 65 3 * 8, /* %y */ 66 -1, /* %fprs */ 67 -1, 68 7 * 8, /* %g1 */ 69 22 * 8, /* %l0 */ 70 4 /* sizeof (%y) */ 71 }; 72 73 static void 74 sparc64obsd_supply_gregset (const struct regset *regset, 75 struct regcache *regcache, 76 int regnum, const void *gregs, size_t len) 77 { 78 const void *fpregs = (char *)gregs + 288; 79 80 if (len < 832) 81 { 82 sparc64_supply_gregset (&sparc64obsd_gregmap, regcache, regnum, gregs); 83 return; 84 } 85 86 sparc64_supply_gregset (&sparc64obsd_core_gregmap, regcache, regnum, gregs); 87 sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs); 88 } 89 90 static void 91 sparc64obsd_supply_fpregset (const struct regset *regset, 92 struct regcache *regcache, 93 int regnum, const void *fpregs, size_t len) 94 { 95 sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs); 96 } 97 98 99 /* Signal trampolines. */ 100 101 /* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page 102 in virtual memory. The randomness makes it somewhat tricky to 103 detect it, but fortunately we can rely on the fact that the start 104 of the sigtramp routine is page-aligned. We recognize the 105 trampoline by looking for the code that invokes the sigreturn 106 system call. The offset where we can find that code varies from 107 release to release. 108 109 By the way, the mapping mentioned above is read-only, so you cannot 110 place a breakpoint in the signal trampoline. */ 111 112 /* Default page size. */ 113 static const int sparc64obsd_page_size = 8192; 114 115 /* Offset for sigreturn(2). */ 116 static const int sparc64obsd_sigreturn_offset[] = { 117 0xf0, /* OpenBSD 3.8 */ 118 0xec, /* OpenBSD 3.6 */ 119 0xe8, /* OpenBSD 3.2 */ 120 -1 121 }; 122 123 static int 124 sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, const char *name) 125 { 126 CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1)); 127 unsigned long insn; 128 const int *offset; 129 130 if (name) 131 return 0; 132 133 for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++) 134 { 135 /* Check for "restore %g0, SYS_sigreturn, %g1". */ 136 insn = sparc_fetch_instruction (start_pc + *offset); 137 if (insn != 0x83e82067) 138 continue; 139 140 /* Check for "t ST_SYSCALL". */ 141 insn = sparc_fetch_instruction (start_pc + *offset + 8); 142 if (insn != 0x91d02000) 143 continue; 144 145 return 1; 146 } 147 148 return 0; 149 } 150 151 static struct sparc_frame_cache * 152 sparc64obsd_frame_cache (struct frame_info *this_frame, void **this_cache) 153 { 154 struct sparc_frame_cache *cache; 155 CORE_ADDR addr; 156 157 if (*this_cache) 158 return (struct sparc_frame_cache *) *this_cache; 159 160 cache = sparc_frame_cache (this_frame, this_cache); 161 gdb_assert (cache == *this_cache); 162 163 /* If we couldn't find the frame's function, we're probably dealing 164 with an on-stack signal trampoline. */ 165 if (cache->pc == 0) 166 { 167 cache->pc = get_frame_pc (this_frame); 168 cache->pc &= ~(sparc64obsd_page_size - 1); 169 170 /* Since we couldn't find the frame's function, the cache was 171 initialized under the assumption that we're frameless. */ 172 sparc_record_save_insn (cache); 173 addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM); 174 if (addr & 1) 175 addr += BIAS; 176 cache->base = addr; 177 } 178 179 /* We find the appropriate instance of `struct sigcontext' at a 180 fixed offset in the signal frame. */ 181 addr = cache->base + 128 + 16; 182 cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, this_frame); 183 184 return cache; 185 } 186 187 static void 188 sparc64obsd_frame_this_id (struct frame_info *this_frame, void **this_cache, 189 struct frame_id *this_id) 190 { 191 struct sparc_frame_cache *cache = 192 sparc64obsd_frame_cache (this_frame, this_cache); 193 194 (*this_id) = frame_id_build (cache->base, cache->pc); 195 } 196 197 static struct value * 198 sparc64obsd_frame_prev_register (struct frame_info *this_frame, 199 void **this_cache, int regnum) 200 { 201 struct sparc_frame_cache *cache = 202 sparc64obsd_frame_cache (this_frame, this_cache); 203 204 return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); 205 } 206 207 static int 208 sparc64obsd_sigtramp_frame_sniffer (const struct frame_unwind *self, 209 struct frame_info *this_frame, 210 void **this_cache) 211 { 212 CORE_ADDR pc = get_frame_pc (this_frame); 213 const char *name; 214 215 find_pc_partial_function (pc, &name, NULL, NULL); 216 if (sparc64obsd_pc_in_sigtramp (pc, name)) 217 return 1; 218 219 return 0; 220 } 221 222 static const struct frame_unwind sparc64obsd_frame_unwind = 223 { 224 SIGTRAMP_FRAME, 225 default_frame_unwind_stop_reason, 226 sparc64obsd_frame_this_id, 227 sparc64obsd_frame_prev_register, 228 NULL, 229 sparc64obsd_sigtramp_frame_sniffer 230 }; 231 232 /* Kernel debugging support. */ 233 234 static struct sparc_frame_cache * 235 sparc64obsd_trapframe_cache (struct frame_info *this_frame, void **this_cache) 236 { 237 struct sparc_frame_cache *cache; 238 CORE_ADDR sp, trapframe_addr; 239 int regnum; 240 241 if (*this_cache) 242 return (struct sparc_frame_cache *) *this_cache; 243 244 cache = sparc_frame_cache (this_frame, this_cache); 245 gdb_assert (cache == *this_cache); 246 247 sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM); 248 trapframe_addr = sp + BIAS + 176; 249 250 cache->saved_regs = trad_frame_alloc_saved_regs (this_frame); 251 252 cache->saved_regs[SPARC64_STATE_REGNUM].addr = trapframe_addr; 253 cache->saved_regs[SPARC64_PC_REGNUM].addr = trapframe_addr + 8; 254 cache->saved_regs[SPARC64_NPC_REGNUM].addr = trapframe_addr + 16; 255 256 for (regnum = SPARC_G0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++) 257 cache->saved_regs[regnum].addr = 258 trapframe_addr + 48 + (regnum - SPARC_G0_REGNUM) * 8; 259 260 return cache; 261 } 262 263 static void 264 sparc64obsd_trapframe_this_id (struct frame_info *this_frame, 265 void **this_cache, struct frame_id *this_id) 266 { 267 struct sparc_frame_cache *cache = 268 sparc64obsd_trapframe_cache (this_frame, this_cache); 269 270 (*this_id) = frame_id_build (cache->base, cache->pc); 271 } 272 273 static struct value * 274 sparc64obsd_trapframe_prev_register (struct frame_info *this_frame, 275 void **this_cache, int regnum) 276 { 277 struct sparc_frame_cache *cache = 278 sparc64obsd_trapframe_cache (this_frame, this_cache); 279 280 return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); 281 } 282 283 static int 284 sparc64obsd_trapframe_sniffer (const struct frame_unwind *self, 285 struct frame_info *this_frame, 286 void **this_cache) 287 { 288 CORE_ADDR pc; 289 ULONGEST pstate; 290 const char *name; 291 292 /* Check whether we are in privileged mode, and bail out if we're not. */ 293 pstate = get_frame_register_unsigned (this_frame, SPARC64_PSTATE_REGNUM); 294 if ((pstate & SPARC64_PSTATE_PRIV) == 0) 295 return 0; 296 297 pc = get_frame_address_in_block (this_frame); 298 find_pc_partial_function (pc, &name, NULL, NULL); 299 if (name && strcmp (name, "Lslowtrap_reenter") == 0) 300 return 1; 301 302 return 0; 303 } 304 305 static const struct frame_unwind sparc64obsd_trapframe_unwind = 306 { 307 NORMAL_FRAME, 308 default_frame_unwind_stop_reason, 309 sparc64obsd_trapframe_this_id, 310 sparc64obsd_trapframe_prev_register, 311 NULL, 312 sparc64obsd_trapframe_sniffer 313 }; 314 315 316 /* Threads support. */ 317 318 /* Offset wthin the thread structure where we can find %fp and %i7. */ 319 #define SPARC64OBSD_UTHREAD_FP_OFFSET 232 320 #define SPARC64OBSD_UTHREAD_PC_OFFSET 240 321 322 static void 323 sparc64obsd_supply_uthread (struct regcache *regcache, 324 int regnum, CORE_ADDR addr) 325 { 326 struct gdbarch *gdbarch = regcache->arch (); 327 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 328 CORE_ADDR fp, fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET; 329 gdb_byte buf[8]; 330 331 gdb_assert (regnum >= -1); 332 333 fp = read_memory_unsigned_integer (fp_addr, 8, byte_order); 334 if (regnum == SPARC_SP_REGNUM || regnum == -1) 335 { 336 store_unsigned_integer (buf, 8, byte_order, fp); 337 regcache->raw_supply (SPARC_SP_REGNUM, buf); 338 339 if (regnum == SPARC_SP_REGNUM) 340 return; 341 } 342 343 if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM 344 || regnum == -1) 345 { 346 CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET; 347 348 i7 = read_memory_unsigned_integer (i7_addr, 8, byte_order); 349 if (regnum == SPARC64_PC_REGNUM || regnum == -1) 350 { 351 store_unsigned_integer (buf, 8, byte_order, i7 + 8); 352 regcache->raw_supply (SPARC64_PC_REGNUM, buf); 353 } 354 if (regnum == SPARC64_NPC_REGNUM || regnum == -1) 355 { 356 store_unsigned_integer (buf, 8, byte_order, i7 + 12); 357 regcache->raw_supply (SPARC64_NPC_REGNUM, buf); 358 } 359 360 if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM) 361 return; 362 } 363 364 sparc_supply_rwindow (regcache, fp, regnum); 365 } 366 367 static void 368 sparc64obsd_collect_uthread(const struct regcache *regcache, 369 int regnum, CORE_ADDR addr) 370 { 371 struct gdbarch *gdbarch = regcache->arch (); 372 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 373 CORE_ADDR sp; 374 gdb_byte buf[8]; 375 376 gdb_assert (regnum >= -1); 377 378 if (regnum == SPARC_SP_REGNUM || regnum == -1) 379 { 380 CORE_ADDR fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET; 381 382 regcache->raw_collect (SPARC_SP_REGNUM, buf); 383 write_memory (fp_addr,buf, 8); 384 } 385 386 if (regnum == SPARC64_PC_REGNUM || regnum == -1) 387 { 388 CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET; 389 390 regcache->raw_collect (SPARC64_PC_REGNUM, buf); 391 i7 = extract_unsigned_integer (buf, 8, byte_order) - 8; 392 write_memory_unsigned_integer (i7_addr, 8, byte_order, i7); 393 394 if (regnum == SPARC64_PC_REGNUM) 395 return; 396 } 397 398 regcache->raw_collect (SPARC_SP_REGNUM, buf); 399 sp = extract_unsigned_integer (buf, 8, byte_order); 400 sparc_collect_rwindow (regcache, sp, regnum); 401 } 402 403 404 static const struct regset sparc64obsd_gregset = 405 { 406 NULL, sparc64obsd_supply_gregset, NULL 407 }; 408 409 static const struct regset sparc64obsd_fpregset = 410 { 411 NULL, sparc64obsd_supply_fpregset, NULL 412 }; 413 414 static void 415 sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 416 { 417 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); 418 419 tdep->gregset = &sparc64obsd_gregset; 420 tdep->sizeof_gregset = 288; 421 tdep->fpregset = &sparc64obsd_fpregset; 422 tdep->sizeof_fpregset = 272; 423 424 /* Make sure we can single-step "new" syscalls. */ 425 tdep->step_trap = sparcnbsd_step_trap; 426 427 frame_unwind_append_unwinder (gdbarch, &sparc64obsd_frame_unwind); 428 frame_unwind_append_unwinder (gdbarch, &sparc64obsd_trapframe_unwind); 429 430 sparc64_init_abi (info, gdbarch); 431 obsd_init_abi (info, gdbarch); 432 433 /* OpenBSD/sparc64 has SVR4-style shared libraries. */ 434 set_solib_svr4_fetch_link_map_offsets 435 (gdbarch, svr4_lp64_fetch_link_map_offsets); 436 set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver); 437 438 /* OpenBSD provides a user-level threads implementation. */ 439 bsd_uthread_set_supply_uthread (gdbarch, sparc64obsd_supply_uthread); 440 bsd_uthread_set_collect_uthread (gdbarch, sparc64obsd_collect_uthread); 441 } 442 443 void _initialize_sparc64obsd_tdep (); 444 void 445 _initialize_sparc64obsd_tdep () 446 { 447 gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, 448 GDB_OSABI_OPENBSD, sparc64obsd_init_abi); 449 } 450