| 1 | /* Target-dependent code for OpenBSD/sparc64. |
| 2 | |
| 3 | Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
| 4 | Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "frame.h" |
| 23 | #include "frame-unwind.h" |
| 24 | #include "gdbcore.h" |
| 25 | #include "osabi.h" |
| 26 | #include "regcache.h" |
| 27 | #include "regset.h" |
| 28 | #include "symtab.h" |
| 29 | #include "objfiles.h" |
| 30 | #include "trad-frame.h" |
| 31 | |
| 32 | #include "gdb_assert.h" |
| 33 | |
| 34 | #include "obsd-tdep.h" |
| 35 | #include "sparc64-tdep.h" |
| 36 | #include "solib-svr4.h" |
| 37 | #include "bsd-uthread.h" |
| 38 | |
| 39 | /* OpenBSD uses the traditional NetBSD core file format, even for |
| 40 | ports that use ELF. The core files don't use multiple register |
| 41 | sets. Instead, the general-purpose and floating-point registers |
| 42 | are lumped together in a single section. Unlike on NetBSD, OpenBSD |
| 43 | uses a different layout for its general-purpose registers than the |
| 44 | layout used for ptrace(2). */ |
| 45 | |
| 46 | /* From <machine/reg.h>. */ |
| 47 | const struct sparc_gregset sparc64obsd_core_gregset = |
| 48 | { |
| 49 | 0 * 8, /* "tstate" */ |
| 50 | 1 * 8, /* %pc */ |
| 51 | 2 * 8, /* %npc */ |
| 52 | 3 * 8, /* %y */ |
| 53 | -1, /* %fprs */ |
| 54 | -1, |
| 55 | 7 * 8, /* %g1 */ |
| 56 | 22 * 8, /* %l0 */ |
| 57 | 4 /* sizeof (%y) */ |
| 58 | }; |
| 59 | |
| 60 | static void |
| 61 | sparc64obsd_supply_gregset (const struct regset *regset, |
| 62 | struct regcache *regcache, |
| 63 | int regnum, const void *gregs, size_t len) |
| 64 | { |
| 65 | const char *regs = gregs; |
| 66 | |
| 67 | sparc64_supply_gregset (&sparc64obsd_core_gregset, regcache, regnum, regs); |
| 68 | sparc64_supply_fpregset (regcache, regnum, regs + 288); |
| 69 | } |
| 70 | \f |
| 71 | |
| 72 | /* Signal trampolines. */ |
| 73 | |
| 74 | /* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page |
| 75 | in virtual memory. The randomness makes it somewhat tricky to |
| 76 | detect it, but fortunately we can rely on the fact that the start |
| 77 | of the sigtramp routine is page-aligned. We recognize the |
| 78 | trampoline by looking for the code that invokes the sigreturn |
| 79 | system call. The offset where we can find that code varies from |
| 80 | release to release. |
| 81 | |
| 82 | By the way, the mapping mentioned above is read-only, so you cannot |
| 83 | place a breakpoint in the signal trampoline. */ |
| 84 | |
| 85 | /* Default page size. */ |
| 86 | static const int sparc64obsd_page_size = 8192; |
| 87 | |
| 88 | /* Offset for sigreturn(2). */ |
| 89 | static const int sparc64obsd_sigreturn_offset[] = { |
| 90 | 0xf0, /* OpenBSD 3.8 */ |
| 91 | 0xec, /* OpenBSD 3.6 */ |
| 92 | 0xe8, /* OpenBSD 3.2 */ |
| 93 | -1 |
| 94 | }; |
| 95 | |
| 96 | static int |
| 97 | sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name) |
| 98 | { |
| 99 | CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1)); |
| 100 | unsigned long insn; |
| 101 | const int *offset; |
| 102 | |
| 103 | if (name) |
| 104 | return 0; |
| 105 | |
| 106 | for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++) |
| 107 | { |
| 108 | /* Check for "restore %g0, SYS_sigreturn, %g1". */ |
| 109 | insn = sparc_fetch_instruction (start_pc + *offset); |
| 110 | if (insn != 0x83e82067) |
| 111 | continue; |
| 112 | |
| 113 | /* Check for "t ST_SYSCALL". */ |
| 114 | insn = sparc_fetch_instruction (start_pc + *offset + 8); |
| 115 | if (insn != 0x91d02000) |
| 116 | continue; |
| 117 | |
| 118 | return 1; |
| 119 | } |
| 120 | |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | static struct sparc_frame_cache * |
| 125 | sparc64obsd_frame_cache (struct frame_info *this_frame, void **this_cache) |
| 126 | { |
| 127 | struct sparc_frame_cache *cache; |
| 128 | CORE_ADDR addr; |
| 129 | |
| 130 | if (*this_cache) |
| 131 | return *this_cache; |
| 132 | |
| 133 | cache = sparc_frame_cache (this_frame, this_cache); |
| 134 | gdb_assert (cache == *this_cache); |
| 135 | |
| 136 | /* If we couldn't find the frame's function, we're probably dealing |
| 137 | with an on-stack signal trampoline. */ |
| 138 | if (cache->pc == 0) |
| 139 | { |
| 140 | cache->pc = get_frame_pc (this_frame); |
| 141 | cache->pc &= ~(sparc64obsd_page_size - 1); |
| 142 | |
| 143 | /* Since we couldn't find the frame's function, the cache was |
| 144 | initialized under the assumption that we're frameless. */ |
| 145 | cache->frameless_p = 0; |
| 146 | addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM); |
| 147 | if (addr & 1) |
| 148 | addr += BIAS; |
| 149 | cache->base = addr; |
| 150 | } |
| 151 | |
| 152 | /* We find the appropriate instance of `struct sigcontext' at a |
| 153 | fixed offset in the signal frame. */ |
| 154 | addr = cache->base + 128 + 16; |
| 155 | cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, this_frame); |
| 156 | |
| 157 | return cache; |
| 158 | } |
| 159 | |
| 160 | static void |
| 161 | sparc64obsd_frame_this_id (struct frame_info *this_frame, void **this_cache, |
| 162 | struct frame_id *this_id) |
| 163 | { |
| 164 | struct sparc_frame_cache *cache = |
| 165 | sparc64obsd_frame_cache (this_frame, this_cache); |
| 166 | |
| 167 | (*this_id) = frame_id_build (cache->base, cache->pc); |
| 168 | } |
| 169 | |
| 170 | static struct value * |
| 171 | sparc64obsd_frame_prev_register (struct frame_info *this_frame, |
| 172 | void **this_cache, int regnum) |
| 173 | { |
| 174 | struct sparc_frame_cache *cache = |
| 175 | sparc64obsd_frame_cache (this_frame, this_cache); |
| 176 | |
| 177 | return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); |
| 178 | } |
| 179 | |
| 180 | static int |
| 181 | sparc64obsd_sigtramp_frame_sniffer (const struct frame_unwind *self, |
| 182 | struct frame_info *this_frame, |
| 183 | void **this_cache) |
| 184 | { |
| 185 | CORE_ADDR pc = get_frame_pc (this_frame); |
| 186 | char *name; |
| 187 | |
| 188 | find_pc_partial_function (pc, &name, NULL, NULL); |
| 189 | if (sparc64obsd_pc_in_sigtramp (pc, name)) |
| 190 | return 1; |
| 191 | |
| 192 | return 0; |
| 193 | } |
| 194 | |
| 195 | static const struct frame_unwind sparc64obsd_frame_unwind = |
| 196 | { |
| 197 | SIGTRAMP_FRAME, |
| 198 | sparc64obsd_frame_this_id, |
| 199 | sparc64obsd_frame_prev_register, |
| 200 | NULL, |
| 201 | sparc64obsd_sigtramp_frame_sniffer |
| 202 | }; |
| 203 | \f |
| 204 | /* Kernel debugging support. */ |
| 205 | |
| 206 | static struct sparc_frame_cache * |
| 207 | sparc64obsd_trapframe_cache (struct frame_info *this_frame, void **this_cache) |
| 208 | { |
| 209 | struct sparc_frame_cache *cache; |
| 210 | CORE_ADDR sp, trapframe_addr; |
| 211 | int regnum; |
| 212 | |
| 213 | if (*this_cache) |
| 214 | return *this_cache; |
| 215 | |
| 216 | cache = sparc_frame_cache (this_frame, this_cache); |
| 217 | gdb_assert (cache == *this_cache); |
| 218 | |
| 219 | sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM); |
| 220 | trapframe_addr = sp + BIAS + 176; |
| 221 | |
| 222 | cache->saved_regs = trad_frame_alloc_saved_regs (this_frame); |
| 223 | |
| 224 | cache->saved_regs[SPARC64_STATE_REGNUM].addr = trapframe_addr; |
| 225 | cache->saved_regs[SPARC64_PC_REGNUM].addr = trapframe_addr + 8; |
| 226 | cache->saved_regs[SPARC64_NPC_REGNUM].addr = trapframe_addr + 16; |
| 227 | |
| 228 | for (regnum = SPARC_G0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++) |
| 229 | cache->saved_regs[regnum].addr = |
| 230 | trapframe_addr + 48 + (regnum - SPARC_G0_REGNUM) * 8; |
| 231 | |
| 232 | return cache; |
| 233 | } |
| 234 | |
| 235 | static void |
| 236 | sparc64obsd_trapframe_this_id (struct frame_info *this_frame, |
| 237 | void **this_cache, struct frame_id *this_id) |
| 238 | { |
| 239 | struct sparc_frame_cache *cache = |
| 240 | sparc64obsd_trapframe_cache (this_frame, this_cache); |
| 241 | |
| 242 | (*this_id) = frame_id_build (cache->base, cache->pc); |
| 243 | } |
| 244 | |
| 245 | static struct value * |
| 246 | sparc64obsd_trapframe_prev_register (struct frame_info *this_frame, |
| 247 | void **this_cache, int regnum) |
| 248 | { |
| 249 | struct sparc_frame_cache *cache = |
| 250 | sparc64obsd_trapframe_cache (this_frame, this_cache); |
| 251 | |
| 252 | return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); |
| 253 | } |
| 254 | |
| 255 | static int |
| 256 | sparc64obsd_trapframe_sniffer (const struct frame_unwind *self, |
| 257 | struct frame_info *this_frame, |
| 258 | void **this_cache) |
| 259 | { |
| 260 | CORE_ADDR pc; |
| 261 | ULONGEST pstate; |
| 262 | char *name; |
| 263 | |
| 264 | /* Check whether we are in privileged mode, and bail out if we're not. */ |
| 265 | pstate = get_frame_register_unsigned (this_frame, SPARC64_PSTATE_REGNUM); |
| 266 | if ((pstate & SPARC64_PSTATE_PRIV) == 0) |
| 267 | return 0; |
| 268 | |
| 269 | pc = get_frame_address_in_block (this_frame); |
| 270 | find_pc_partial_function (pc, &name, NULL, NULL); |
| 271 | if (name && strcmp (name, "Lslowtrap_reenter") == 0) |
| 272 | return 1; |
| 273 | |
| 274 | return 0; |
| 275 | } |
| 276 | |
| 277 | static const struct frame_unwind sparc64obsd_trapframe_unwind = |
| 278 | { |
| 279 | NORMAL_FRAME, |
| 280 | sparc64obsd_trapframe_this_id, |
| 281 | sparc64obsd_trapframe_prev_register, |
| 282 | NULL, |
| 283 | sparc64obsd_trapframe_sniffer |
| 284 | }; |
| 285 | \f |
| 286 | |
| 287 | /* Threads support. */ |
| 288 | |
| 289 | /* Offset wthin the thread structure where we can find %fp and %i7. */ |
| 290 | #define SPARC64OBSD_UTHREAD_FP_OFFSET 232 |
| 291 | #define SPARC64OBSD_UTHREAD_PC_OFFSET 240 |
| 292 | |
| 293 | static void |
| 294 | sparc64obsd_supply_uthread (struct regcache *regcache, |
| 295 | int regnum, CORE_ADDR addr) |
| 296 | { |
| 297 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 298 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 299 | CORE_ADDR fp, fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET; |
| 300 | gdb_byte buf[8]; |
| 301 | |
| 302 | gdb_assert (regnum >= -1); |
| 303 | |
| 304 | fp = read_memory_unsigned_integer (fp_addr, 8, byte_order); |
| 305 | if (regnum == SPARC_SP_REGNUM || regnum == -1) |
| 306 | { |
| 307 | store_unsigned_integer (buf, 8, byte_order, fp); |
| 308 | regcache_raw_supply (regcache, SPARC_SP_REGNUM, buf); |
| 309 | |
| 310 | if (regnum == SPARC_SP_REGNUM) |
| 311 | return; |
| 312 | } |
| 313 | |
| 314 | if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM |
| 315 | || regnum == -1) |
| 316 | { |
| 317 | CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET; |
| 318 | |
| 319 | i7 = read_memory_unsigned_integer (i7_addr, 8, byte_order); |
| 320 | if (regnum == SPARC64_PC_REGNUM || regnum == -1) |
| 321 | { |
| 322 | store_unsigned_integer (buf, 8, byte_order, i7 + 8); |
| 323 | regcache_raw_supply (regcache, SPARC64_PC_REGNUM, buf); |
| 324 | } |
| 325 | if (regnum == SPARC64_NPC_REGNUM || regnum == -1) |
| 326 | { |
| 327 | store_unsigned_integer (buf, 8, byte_order, i7 + 12); |
| 328 | regcache_raw_supply (regcache, SPARC64_NPC_REGNUM, buf); |
| 329 | } |
| 330 | |
| 331 | if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM) |
| 332 | return; |
| 333 | } |
| 334 | |
| 335 | sparc_supply_rwindow (regcache, fp, regnum); |
| 336 | } |
| 337 | |
| 338 | static void |
| 339 | sparc64obsd_collect_uthread(const struct regcache *regcache, |
| 340 | int regnum, CORE_ADDR addr) |
| 341 | { |
| 342 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 343 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 344 | CORE_ADDR sp; |
| 345 | gdb_byte buf[8]; |
| 346 | |
| 347 | gdb_assert (regnum >= -1); |
| 348 | |
| 349 | if (regnum == SPARC_SP_REGNUM || regnum == -1) |
| 350 | { |
| 351 | CORE_ADDR fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET; |
| 352 | |
| 353 | regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf); |
| 354 | write_memory (fp_addr,buf, 8); |
| 355 | } |
| 356 | |
| 357 | if (regnum == SPARC64_PC_REGNUM || regnum == -1) |
| 358 | { |
| 359 | CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET; |
| 360 | |
| 361 | regcache_raw_collect (regcache, SPARC64_PC_REGNUM, buf); |
| 362 | i7 = extract_unsigned_integer (buf, 8, byte_order) - 8; |
| 363 | write_memory_unsigned_integer (i7_addr, 8, byte_order, i7); |
| 364 | |
| 365 | if (regnum == SPARC64_PC_REGNUM) |
| 366 | return; |
| 367 | } |
| 368 | |
| 369 | regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf); |
| 370 | sp = extract_unsigned_integer (buf, 8, byte_order); |
| 371 | sparc_collect_rwindow (regcache, sp, regnum); |
| 372 | } |
| 373 | \f |
| 374 | |
| 375 | static void |
| 376 | sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 377 | { |
| 378 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 379 | |
| 380 | tdep->gregset = regset_alloc (gdbarch, sparc64obsd_supply_gregset, NULL); |
| 381 | tdep->sizeof_gregset = 832; |
| 382 | |
| 383 | /* Make sure we can single-step "new" syscalls. */ |
| 384 | tdep->step_trap = sparcnbsd_step_trap; |
| 385 | |
| 386 | frame_unwind_append_unwinder (gdbarch, &sparc64obsd_frame_unwind); |
| 387 | frame_unwind_append_unwinder (gdbarch, &sparc64obsd_trapframe_unwind); |
| 388 | |
| 389 | sparc64_init_abi (info, gdbarch); |
| 390 | |
| 391 | /* OpenBSD/sparc64 has SVR4-style shared libraries. */ |
| 392 | set_solib_svr4_fetch_link_map_offsets |
| 393 | (gdbarch, svr4_lp64_fetch_link_map_offsets); |
| 394 | set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver); |
| 395 | |
| 396 | /* OpenBSD provides a user-level threads implementation. */ |
| 397 | bsd_uthread_set_supply_uthread (gdbarch, sparc64obsd_supply_uthread); |
| 398 | bsd_uthread_set_collect_uthread (gdbarch, sparc64obsd_collect_uthread); |
| 399 | } |
| 400 | \f |
| 401 | |
| 402 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 403 | void _initialize_sparc64obsd_tdep (void); |
| 404 | |
| 405 | void |
| 406 | _initialize_sparc64obsd_tdep (void) |
| 407 | { |
| 408 | gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, |
| 409 | GDB_OSABI_OPENBSD_ELF, sparc64obsd_init_abi); |
| 410 | } |