| 1 | /* Target-dependent code for GNU/Linux running on PA-RISC, for GDB. |
| 2 | |
| 3 | Copyright 2004 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 2 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, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #include "defs.h" |
| 22 | #include "gdbcore.h" |
| 23 | #include "osabi.h" |
| 24 | #include "target.h" |
| 25 | #include "objfiles.h" |
| 26 | #include "solib-svr4.h" |
| 27 | #include "glibc-tdep.h" |
| 28 | #include "frame-unwind.h" |
| 29 | #include "trad-frame.h" |
| 30 | #include "dwarf2-frame.h" |
| 31 | #include "value.h" |
| 32 | #include "hppa-tdep.h" |
| 33 | |
| 34 | #include "elf/common.h" |
| 35 | |
| 36 | #if 0 |
| 37 | /* Convert DWARF register number REG to the appropriate register |
| 38 | number used by GDB. */ |
| 39 | static int |
| 40 | hppa_dwarf_reg_to_regnum (int reg) |
| 41 | { |
| 42 | /* registers 0 - 31 are the same in both sets */ |
| 43 | if (reg < 32) |
| 44 | return reg; |
| 45 | |
| 46 | /* dwarf regs 32 to 85 are fpregs 4 - 31 */ |
| 47 | if (reg >= 32 && reg <= 85) |
| 48 | return HPPA_FP4_REGNUM + (reg - 32); |
| 49 | |
| 50 | warning (_("Unmapped DWARF Register #%d encountered."), reg); |
| 51 | return -1; |
| 52 | } |
| 53 | #endif |
| 54 | |
| 55 | static void |
| 56 | hppa_linux_target_write_pc (CORE_ADDR v, ptid_t ptid) |
| 57 | { |
| 58 | /* Probably this should be done by the kernel, but it isn't. */ |
| 59 | write_register_pid (HPPA_PCOQ_HEAD_REGNUM, v | 0x3, ptid); |
| 60 | write_register_pid (HPPA_PCOQ_TAIL_REGNUM, (v + 4) | 0x3, ptid); |
| 61 | } |
| 62 | |
| 63 | /* An instruction to match. */ |
| 64 | struct insn_pattern |
| 65 | { |
| 66 | unsigned int data; /* See if it matches this.... */ |
| 67 | unsigned int mask; /* ... with this mask. */ |
| 68 | }; |
| 69 | |
| 70 | /* See bfd/elf32-hppa.c */ |
| 71 | static struct insn_pattern hppa_long_branch_stub[] = { |
| 72 | /* ldil LR'xxx,%r1 */ |
| 73 | { 0x20200000, 0xffe00000 }, |
| 74 | /* be,n RR'xxx(%sr4,%r1) */ |
| 75 | { 0xe0202002, 0xffe02002 }, |
| 76 | { 0, 0 } |
| 77 | }; |
| 78 | |
| 79 | static struct insn_pattern hppa_long_branch_pic_stub[] = { |
| 80 | /* b,l .+8, %r1 */ |
| 81 | { 0xe8200000, 0xffe00000 }, |
| 82 | /* addil LR'xxx - ($PIC_pcrel$0 - 4), %r1 */ |
| 83 | { 0x28200000, 0xffe00000 }, |
| 84 | /* be,n RR'xxxx - ($PIC_pcrel$0 - 8)(%sr4, %r1) */ |
| 85 | { 0xe0202002, 0xffe02002 }, |
| 86 | { 0, 0 } |
| 87 | }; |
| 88 | |
| 89 | static struct insn_pattern hppa_import_stub[] = { |
| 90 | /* addil LR'xxx, %dp */ |
| 91 | { 0x2b600000, 0xffe00000 }, |
| 92 | /* ldw RR'xxx(%r1), %r21 */ |
| 93 | { 0x48350000, 0xffffb000 }, |
| 94 | /* bv %r0(%r21) */ |
| 95 | { 0xeaa0c000, 0xffffffff }, |
| 96 | /* ldw RR'xxx+4(%r1), %r19 */ |
| 97 | { 0x48330000, 0xffffb000 }, |
| 98 | { 0, 0 } |
| 99 | }; |
| 100 | |
| 101 | static struct insn_pattern hppa_import_pic_stub[] = { |
| 102 | /* addil LR'xxx,%r19 */ |
| 103 | { 0x2a600000, 0xffe00000 }, |
| 104 | /* ldw RR'xxx(%r1),%r21 */ |
| 105 | { 0x48350000, 0xffffb000 }, |
| 106 | /* bv %r0(%r21) */ |
| 107 | { 0xeaa0c000, 0xffffffff }, |
| 108 | /* ldw RR'xxx+4(%r1),%r19 */ |
| 109 | { 0x48330000, 0xffffb000 }, |
| 110 | { 0, 0 }, |
| 111 | }; |
| 112 | |
| 113 | static struct insn_pattern hppa_plt_stub[] = { |
| 114 | /* b,l 1b, %r20 - 1b is 3 insns before here */ |
| 115 | { 0xea9f1fdd, 0xffffffff }, |
| 116 | /* depi 0,31,2,%r20 */ |
| 117 | { 0xd6801c1e, 0xffffffff }, |
| 118 | { 0, 0 } |
| 119 | }; |
| 120 | |
| 121 | static struct insn_pattern hppa_sigtramp[] = { |
| 122 | /* ldi 0, %r25 or ldi 1, %r25 */ |
| 123 | { 0x34190000, 0xfffffffd }, |
| 124 | /* ldi __NR_rt_sigreturn, %r20 */ |
| 125 | { 0x3414015a, 0xffffffff }, |
| 126 | /* be,l 0x100(%sr2, %r0), %sr0, %r31 */ |
| 127 | { 0xe4008200, 0xffffffff }, |
| 128 | /* nop */ |
| 129 | { 0x08000240, 0xffffffff }, |
| 130 | { 0, 0 } |
| 131 | }; |
| 132 | |
| 133 | #define HPPA_MAX_INSN_PATTERN_LEN (4) |
| 134 | |
| 135 | /* Return non-zero if the instructions at PC match the series |
| 136 | described in PATTERN, or zero otherwise. PATTERN is an array of |
| 137 | 'struct insn_pattern' objects, terminated by an entry whose mask is |
| 138 | zero. |
| 139 | |
| 140 | When the match is successful, fill INSN[i] with what PATTERN[i] |
| 141 | matched. */ |
| 142 | static int |
| 143 | insns_match_pattern (CORE_ADDR pc, |
| 144 | struct insn_pattern *pattern, |
| 145 | unsigned int *insn) |
| 146 | { |
| 147 | int i; |
| 148 | CORE_ADDR npc = pc; |
| 149 | |
| 150 | for (i = 0; pattern[i].mask; i++) |
| 151 | { |
| 152 | char buf[4]; |
| 153 | |
| 154 | deprecated_read_memory_nobpt (npc, buf, 4); |
| 155 | insn[i] = extract_unsigned_integer (buf, 4); |
| 156 | if ((insn[i] & pattern[i].mask) == pattern[i].data) |
| 157 | npc += 4; |
| 158 | else |
| 159 | return 0; |
| 160 | } |
| 161 | return 1; |
| 162 | } |
| 163 | |
| 164 | /* The relaxed version of the insn matcher allows us to match from somewhere |
| 165 | inside the pattern, by looking backwards in the instruction scheme. */ |
| 166 | static int |
| 167 | insns_match_pattern_relaxed (CORE_ADDR pc, |
| 168 | struct insn_pattern *pattern, |
| 169 | unsigned int *insn) |
| 170 | { |
| 171 | int pat_len = 0; |
| 172 | int offset; |
| 173 | |
| 174 | while (pattern[pat_len].mask) |
| 175 | pat_len++; |
| 176 | |
| 177 | for (offset = 0; offset < pat_len; offset++) |
| 178 | { |
| 179 | if (insns_match_pattern (pc - offset * 4, |
| 180 | pattern, insn)) |
| 181 | return 1; |
| 182 | } |
| 183 | |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | static int |
| 188 | hppa_linux_in_dyncall (CORE_ADDR pc) |
| 189 | { |
| 190 | struct unwind_table_entry *u; |
| 191 | u = find_unwind_entry (hppa_symbol_address ("$$dyncall")); |
| 192 | |
| 193 | if (!u) |
| 194 | return 0; |
| 195 | |
| 196 | return pc >= u->region_start && pc <= u->region_end; |
| 197 | } |
| 198 | |
| 199 | /* There are several kinds of "trampolines" that we need to deal with: |
| 200 | - long branch stubs: these are inserted by the linker when a branch |
| 201 | target is too far away for a branch insn to reach |
| 202 | - plt stubs: these should go into the .plt section, so are easy to find |
| 203 | - import stubs: used to call from object to shared lib or shared lib to |
| 204 | shared lib; these go in regular text sections. In fact the linker tries |
| 205 | to put them throughout the code because branches have limited reachability. |
| 206 | We use the same mechanism as ppc64 to recognize the stub insn patterns. |
| 207 | - $$dyncall: similar to hpux, hppa-linux uses $$dyncall for indirect function |
| 208 | calls. $$dyncall is exported by libgcc.a */ |
| 209 | static int |
| 210 | hppa_linux_in_solib_call_trampoline (CORE_ADDR pc, char *name) |
| 211 | { |
| 212 | unsigned int insn[HPPA_MAX_INSN_PATTERN_LEN]; |
| 213 | int r; |
| 214 | struct unwind_table_entry *u; |
| 215 | |
| 216 | /* on hppa-linux, linker stubs have no unwind information. Since the pattern |
| 217 | matching for linker stubs can be quite slow, we try to avoid it if |
| 218 | we can. */ |
| 219 | u = find_unwind_entry (pc); |
| 220 | |
| 221 | r = in_plt_section (pc, name) |
| 222 | || hppa_linux_in_dyncall (pc) |
| 223 | || (u == NULL |
| 224 | && (insns_match_pattern_relaxed (pc, hppa_import_stub, insn) |
| 225 | || insns_match_pattern_relaxed (pc, hppa_import_pic_stub, insn) |
| 226 | || insns_match_pattern_relaxed (pc, hppa_long_branch_stub, insn) |
| 227 | || insns_match_pattern_relaxed (pc, hppa_long_branch_pic_stub, insn))); |
| 228 | |
| 229 | return r; |
| 230 | } |
| 231 | |
| 232 | static CORE_ADDR |
| 233 | hppa_linux_skip_trampoline_code (CORE_ADDR pc) |
| 234 | { |
| 235 | unsigned int insn[HPPA_MAX_INSN_PATTERN_LEN]; |
| 236 | int dp_rel, pic_rel; |
| 237 | |
| 238 | /* dyncall handles both PLABELs and direct addresses */ |
| 239 | if (hppa_linux_in_dyncall (pc)) |
| 240 | { |
| 241 | pc = (CORE_ADDR) read_register (22); |
| 242 | |
| 243 | /* PLABELs have bit 30 set; if it's a PLABEL, then dereference it */ |
| 244 | if (pc & 0x2) |
| 245 | pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, TARGET_PTR_BIT / 8); |
| 246 | |
| 247 | return pc; |
| 248 | } |
| 249 | |
| 250 | dp_rel = pic_rel = 0; |
| 251 | if ((dp_rel = insns_match_pattern (pc, hppa_import_stub, insn)) |
| 252 | || (pic_rel = insns_match_pattern (pc, hppa_import_pic_stub, insn))) |
| 253 | { |
| 254 | /* Extract the target address from the addil/ldw sequence. */ |
| 255 | pc = hppa_extract_21 (insn[0]) + hppa_extract_14 (insn[1]); |
| 256 | |
| 257 | if (dp_rel) |
| 258 | pc += (CORE_ADDR) read_register (27); |
| 259 | else |
| 260 | pc += (CORE_ADDR) read_register (19); |
| 261 | |
| 262 | /* fallthrough */ |
| 263 | } |
| 264 | |
| 265 | if (in_plt_section (pc, NULL)) |
| 266 | { |
| 267 | pc = (CORE_ADDR) read_memory_integer (pc, TARGET_PTR_BIT / 8); |
| 268 | |
| 269 | /* if the plt slot has not yet been resolved, the target will |
| 270 | be the plt stub */ |
| 271 | if (in_plt_section (pc, NULL)) |
| 272 | { |
| 273 | /* Sanity check: are we pointing to the plt stub? */ |
| 274 | if (insns_match_pattern (pc, hppa_plt_stub, insn)) |
| 275 | { |
| 276 | /* this should point to the fixup routine */ |
| 277 | pc = (CORE_ADDR) read_memory_integer (pc + 8, TARGET_PTR_BIT / 8); |
| 278 | } |
| 279 | else |
| 280 | { |
| 281 | error (_("Cannot resolve plt stub at 0x%s."), |
| 282 | paddr_nz (pc)); |
| 283 | pc = 0; |
| 284 | } |
| 285 | } |
| 286 | } |
| 287 | |
| 288 | return pc; |
| 289 | } |
| 290 | |
| 291 | /* Signal frames. */ |
| 292 | |
| 293 | /* (This is derived from MD_FALLBACK_FRAME_STATE_FOR in gcc.) |
| 294 | |
| 295 | Unfortunately, because of various bugs and changes to the kernel, |
| 296 | we have several cases to deal with. |
| 297 | |
| 298 | In 2.4, the signal trampoline is 4 bytes, and pc should point directly at |
| 299 | the beginning of the trampoline and struct rt_sigframe. |
| 300 | |
| 301 | In <= 2.6.5-rc2-pa3, the signal trampoline is 9 bytes, and pc points at |
| 302 | the 4th word in the trampoline structure. This is wrong, it should point |
| 303 | at the 5th word. This is fixed in 2.6.5-rc2-pa4. |
| 304 | |
| 305 | To detect these cases, we first take pc, align it to 64-bytes |
| 306 | to get the beginning of the signal frame, and then check offsets 0, 4 |
| 307 | and 5 to see if we found the beginning of the trampoline. This will |
| 308 | tell us how to locate the sigcontext structure. |
| 309 | |
| 310 | Note that with a 2.4 64-bit kernel, the signal context is not properly |
| 311 | passed back to userspace so the unwind will not work correctly. */ |
| 312 | static CORE_ADDR |
| 313 | hppa_linux_sigtramp_find_sigcontext (CORE_ADDR pc) |
| 314 | { |
| 315 | unsigned int dummy[HPPA_MAX_INSN_PATTERN_LEN]; |
| 316 | int offs = 0; |
| 317 | int try; |
| 318 | /* offsets to try to find the trampoline */ |
| 319 | static int pcoffs[] = { 0, 4*4, 5*4 }; |
| 320 | /* offsets to the rt_sigframe structure */ |
| 321 | static int sfoffs[] = { 4*4, 10*4, 10*4 }; |
| 322 | CORE_ADDR sp; |
| 323 | |
| 324 | /* Most of the time, this will be correct. The one case when this will |
| 325 | fail is if the user defined an alternate stack, in which case the |
| 326 | beginning of the stack will not be align_down (pc, 64). */ |
| 327 | sp = align_down (pc, 64); |
| 328 | |
| 329 | /* rt_sigreturn trampoline: |
| 330 | 3419000x ldi 0, %r25 or ldi 1, %r25 (x = 0 or 2) |
| 331 | 3414015a ldi __NR_rt_sigreturn, %r20 |
| 332 | e4008200 be,l 0x100(%sr2, %r0), %sr0, %r31 |
| 333 | 08000240 nop */ |
| 334 | |
| 335 | for (try = 0; try < ARRAY_SIZE (pcoffs); try++) |
| 336 | { |
| 337 | if (insns_match_pattern (sp + pcoffs[try], hppa_sigtramp, dummy)) |
| 338 | { |
| 339 | offs = sfoffs[try]; |
| 340 | break; |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | if (offs == 0) |
| 345 | { |
| 346 | if (insns_match_pattern (pc, hppa_sigtramp, dummy)) |
| 347 | { |
| 348 | /* sigaltstack case: we have no way of knowing which offset to |
| 349 | use in this case; default to new kernel handling. If this is |
| 350 | wrong the unwinding will fail. */ |
| 351 | try = 2; |
| 352 | sp = pc - pcoffs[try]; |
| 353 | } |
| 354 | else |
| 355 | { |
| 356 | return 0; |
| 357 | } |
| 358 | } |
| 359 | |
| 360 | /* sp + sfoffs[try] points to a struct rt_sigframe, which contains |
| 361 | a struct siginfo and a struct ucontext. struct ucontext contains |
| 362 | a struct sigcontext. Return an offset to this sigcontext here. Too |
| 363 | bad we cannot include system specific headers :-(. |
| 364 | sizeof(struct siginfo) == 128 |
| 365 | offsetof(struct ucontext, uc_mcontext) == 24. */ |
| 366 | return sp + sfoffs[try] + 128 + 24; |
| 367 | } |
| 368 | |
| 369 | struct hppa_linux_sigtramp_unwind_cache |
| 370 | { |
| 371 | CORE_ADDR base; |
| 372 | struct trad_frame_saved_reg *saved_regs; |
| 373 | }; |
| 374 | |
| 375 | static struct hppa_linux_sigtramp_unwind_cache * |
| 376 | hppa_linux_sigtramp_frame_unwind_cache (struct frame_info *next_frame, |
| 377 | void **this_cache) |
| 378 | { |
| 379 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 380 | struct hppa_linux_sigtramp_unwind_cache *info; |
| 381 | CORE_ADDR pc, scptr; |
| 382 | int i; |
| 383 | |
| 384 | if (*this_cache) |
| 385 | return *this_cache; |
| 386 | |
| 387 | info = FRAME_OBSTACK_ZALLOC (struct hppa_linux_sigtramp_unwind_cache); |
| 388 | *this_cache = info; |
| 389 | info->saved_regs = trad_frame_alloc_saved_regs (next_frame); |
| 390 | |
| 391 | pc = frame_pc_unwind (next_frame); |
| 392 | scptr = hppa_linux_sigtramp_find_sigcontext (pc); |
| 393 | |
| 394 | /* structure of struct sigcontext: |
| 395 | |
| 396 | struct sigcontext { |
| 397 | unsigned long sc_flags; |
| 398 | unsigned long sc_gr[32]; |
| 399 | unsigned long long sc_fr[32]; |
| 400 | unsigned long sc_iasq[2]; |
| 401 | unsigned long sc_iaoq[2]; |
| 402 | unsigned long sc_sar; */ |
| 403 | |
| 404 | /* Skip sc_flags. */ |
| 405 | scptr += 4; |
| 406 | |
| 407 | /* GR[0] is the psw, we don't restore that. */ |
| 408 | scptr += 4; |
| 409 | |
| 410 | /* General registers. */ |
| 411 | for (i = 1; i < 32; i++) |
| 412 | { |
| 413 | info->saved_regs[HPPA_R0_REGNUM + i].addr = scptr; |
| 414 | scptr += 4; |
| 415 | } |
| 416 | |
| 417 | /* Pad. */ |
| 418 | scptr += 4; |
| 419 | |
| 420 | /* FP regs; FP0-3 are not restored. */ |
| 421 | scptr += (8 * 4); |
| 422 | |
| 423 | for (i = 4; i < 32; i++) |
| 424 | { |
| 425 | info->saved_regs[HPPA_FP0_REGNUM + (i * 2)].addr = scptr; |
| 426 | scptr += 4; |
| 427 | info->saved_regs[HPPA_FP0_REGNUM + (i * 2) + 1].addr = scptr; |
| 428 | scptr += 4; |
| 429 | } |
| 430 | |
| 431 | /* IASQ/IAOQ. */ |
| 432 | info->saved_regs[HPPA_PCSQ_HEAD_REGNUM].addr = scptr; |
| 433 | scptr += 4; |
| 434 | info->saved_regs[HPPA_PCSQ_TAIL_REGNUM].addr = scptr; |
| 435 | scptr += 4; |
| 436 | |
| 437 | info->saved_regs[HPPA_PCOQ_HEAD_REGNUM].addr = scptr; |
| 438 | scptr += 4; |
| 439 | info->saved_regs[HPPA_PCOQ_TAIL_REGNUM].addr = scptr; |
| 440 | scptr += 4; |
| 441 | |
| 442 | info->base = frame_unwind_register_unsigned (next_frame, HPPA_SP_REGNUM); |
| 443 | |
| 444 | return info; |
| 445 | } |
| 446 | |
| 447 | static void |
| 448 | hppa_linux_sigtramp_frame_this_id (struct frame_info *next_frame, |
| 449 | void **this_prologue_cache, |
| 450 | struct frame_id *this_id) |
| 451 | { |
| 452 | struct hppa_linux_sigtramp_unwind_cache *info |
| 453 | = hppa_linux_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); |
| 454 | *this_id = frame_id_build (info->base, frame_pc_unwind (next_frame)); |
| 455 | } |
| 456 | |
| 457 | static void |
| 458 | hppa_linux_sigtramp_frame_prev_register (struct frame_info *next_frame, |
| 459 | void **this_prologue_cache, |
| 460 | int regnum, int *optimizedp, |
| 461 | enum lval_type *lvalp, |
| 462 | CORE_ADDR *addrp, |
| 463 | int *realnump, void *valuep) |
| 464 | { |
| 465 | struct hppa_linux_sigtramp_unwind_cache *info |
| 466 | = hppa_linux_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); |
| 467 | hppa_frame_prev_register_helper (next_frame, info->saved_regs, regnum, |
| 468 | optimizedp, lvalp, addrp, realnump, valuep); |
| 469 | } |
| 470 | |
| 471 | static const struct frame_unwind hppa_linux_sigtramp_frame_unwind = { |
| 472 | SIGTRAMP_FRAME, |
| 473 | hppa_linux_sigtramp_frame_this_id, |
| 474 | hppa_linux_sigtramp_frame_prev_register |
| 475 | }; |
| 476 | |
| 477 | /* hppa-linux always uses "new-style" rt-signals. The signal handler's return |
| 478 | address should point to a signal trampoline on the stack. The signal |
| 479 | trampoline is embedded in a rt_sigframe structure that is aligned on |
| 480 | the stack. We take advantage of the fact that sp must be 64-byte aligned, |
| 481 | and the trampoline is small, so by rounding down the trampoline address |
| 482 | we can find the beginning of the struct rt_sigframe. */ |
| 483 | static const struct frame_unwind * |
| 484 | hppa_linux_sigtramp_unwind_sniffer (struct frame_info *next_frame) |
| 485 | { |
| 486 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
| 487 | |
| 488 | if (hppa_linux_sigtramp_find_sigcontext (pc)) |
| 489 | return &hppa_linux_sigtramp_frame_unwind; |
| 490 | |
| 491 | return NULL; |
| 492 | } |
| 493 | |
| 494 | /* Attempt to find (and return) the global pointer for the given |
| 495 | function. |
| 496 | |
| 497 | This is a rather nasty bit of code searchs for the .dynamic section |
| 498 | in the objfile corresponding to the pc of the function we're trying |
| 499 | to call. Once it finds the addresses at which the .dynamic section |
| 500 | lives in the child process, it scans the Elf32_Dyn entries for a |
| 501 | DT_PLTGOT tag. If it finds one of these, the corresponding |
| 502 | d_un.d_ptr value is the global pointer. */ |
| 503 | |
| 504 | static CORE_ADDR |
| 505 | hppa_linux_find_global_pointer (struct value *function) |
| 506 | { |
| 507 | struct obj_section *faddr_sect; |
| 508 | CORE_ADDR faddr; |
| 509 | |
| 510 | faddr = value_as_address (function); |
| 511 | |
| 512 | /* Is this a plabel? If so, dereference it to get the gp value. */ |
| 513 | if (faddr & 2) |
| 514 | { |
| 515 | int status; |
| 516 | char buf[4]; |
| 517 | |
| 518 | faddr &= ~3; |
| 519 | |
| 520 | status = target_read_memory (faddr + 4, buf, sizeof (buf)); |
| 521 | if (status == 0) |
| 522 | return extract_unsigned_integer (buf, sizeof (buf)); |
| 523 | } |
| 524 | |
| 525 | /* If the address is in the plt section, then the real function hasn't |
| 526 | yet been fixed up by the linker so we cannot determine the gp of |
| 527 | that function. */ |
| 528 | if (in_plt_section (faddr, NULL)) |
| 529 | return 0; |
| 530 | |
| 531 | faddr_sect = find_pc_section (faddr); |
| 532 | if (faddr_sect != NULL) |
| 533 | { |
| 534 | struct obj_section *osect; |
| 535 | |
| 536 | ALL_OBJFILE_OSECTIONS (faddr_sect->objfile, osect) |
| 537 | { |
| 538 | if (strcmp (osect->the_bfd_section->name, ".dynamic") == 0) |
| 539 | break; |
| 540 | } |
| 541 | |
| 542 | if (osect < faddr_sect->objfile->sections_end) |
| 543 | { |
| 544 | CORE_ADDR addr; |
| 545 | |
| 546 | addr = osect->addr; |
| 547 | while (addr < osect->endaddr) |
| 548 | { |
| 549 | int status; |
| 550 | LONGEST tag; |
| 551 | char buf[4]; |
| 552 | |
| 553 | status = target_read_memory (addr, buf, sizeof (buf)); |
| 554 | if (status != 0) |
| 555 | break; |
| 556 | tag = extract_signed_integer (buf, sizeof (buf)); |
| 557 | |
| 558 | if (tag == DT_PLTGOT) |
| 559 | { |
| 560 | CORE_ADDR global_pointer; |
| 561 | |
| 562 | status = target_read_memory (addr + 4, buf, sizeof (buf)); |
| 563 | if (status != 0) |
| 564 | break; |
| 565 | global_pointer = extract_unsigned_integer (buf, sizeof (buf)); |
| 566 | |
| 567 | /* The payoff... */ |
| 568 | return global_pointer; |
| 569 | } |
| 570 | |
| 571 | if (tag == DT_NULL) |
| 572 | break; |
| 573 | |
| 574 | addr += 8; |
| 575 | } |
| 576 | } |
| 577 | } |
| 578 | return 0; |
| 579 | } |
| 580 | |
| 581 | /* Forward declarations. */ |
| 582 | extern initialize_file_ftype _initialize_hppa_linux_tdep; |
| 583 | |
| 584 | static void |
| 585 | hppa_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 586 | { |
| 587 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 588 | |
| 589 | /* GNU/Linux is always ELF. */ |
| 590 | tdep->is_elf = 1; |
| 591 | |
| 592 | tdep->find_global_pointer = hppa_linux_find_global_pointer; |
| 593 | |
| 594 | set_gdbarch_write_pc (gdbarch, hppa_linux_target_write_pc); |
| 595 | |
| 596 | frame_unwind_append_sniffer (gdbarch, hppa_linux_sigtramp_unwind_sniffer); |
| 597 | |
| 598 | /* GNU/Linux uses SVR4-style shared libraries. */ |
| 599 | set_solib_svr4_fetch_link_map_offsets |
| 600 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
| 601 | |
| 602 | tdep->in_solib_call_trampoline = hppa_linux_in_solib_call_trampoline; |
| 603 | set_gdbarch_skip_trampoline_code |
| 604 | (gdbarch, hppa_linux_skip_trampoline_code); |
| 605 | |
| 606 | /* GNU/Linux uses the dynamic linker included in the GNU C Library. */ |
| 607 | set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver); |
| 608 | |
| 609 | /* On hppa-linux, currently, sizeof(long double) == 8. There has been |
| 610 | some discussions to support 128-bit long double, but it requires some |
| 611 | more work in gcc and glibc first. */ |
| 612 | set_gdbarch_long_double_bit (gdbarch, 64); |
| 613 | |
| 614 | #if 0 |
| 615 | /* Dwarf-2 unwinding support. Not yet working. */ |
| 616 | set_gdbarch_dwarf_reg_to_regnum (gdbarch, hppa_dwarf_reg_to_regnum); |
| 617 | set_gdbarch_dwarf2_reg_to_regnum (gdbarch, hppa_dwarf_reg_to_regnum); |
| 618 | frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer); |
| 619 | frame_base_append_sniffer (gdbarch, dwarf2_frame_base_sniffer); |
| 620 | #endif |
| 621 | |
| 622 | /* Enable TLS support. */ |
| 623 | set_gdbarch_fetch_tls_load_module_address (gdbarch, |
| 624 | svr4_fetch_objfile_link_map); |
| 625 | } |
| 626 | |
| 627 | void |
| 628 | _initialize_hppa_linux_tdep (void) |
| 629 | { |
| 630 | gdbarch_register_osabi (bfd_arch_hppa, 0, GDB_OSABI_LINUX, hppa_linux_init_abi); |
| 631 | } |