1 /* Motorola m68k target-dependent support for GNU/Linux. 2 3 Copyright (C) 1996-2024 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 "extract-store-integer.h" 21 #include "gdbcore.h" 22 #include "frame.h" 23 #include "target.h" 24 #include "gdbtypes.h" 25 #include "osabi.h" 26 #include "regcache.h" 27 #include "objfiles.h" 28 #include "symtab.h" 29 #include "m68k-tdep.h" 30 #include "trad-frame.h" 31 #include "frame-unwind.h" 32 #include "glibc-tdep.h" 33 #include "solib-svr4.h" 34 #include "auxv.h" 35 #include "observable.h" 36 #include "elf/common.h" 37 #include "linux-tdep.h" 38 #include "regset.h" 39 40 /* Offsets (in target ints) into jmp_buf. */ 42 43 #define M68K_LINUX_JB_ELEMENT_SIZE 4 44 #define M68K_LINUX_JB_PC 7 45 46 /* Check whether insn1 and insn2 are parts of a signal trampoline. */ 47 48 #define IS_SIGTRAMP(insn1, insn2) \ 49 (/* addaw #20,sp; moveq #119,d0; trap #0 */ \ 50 (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \ 51 /* moveq #119,d0; trap #0 */ \ 52 || insn1 == 0x70774e40) 53 54 #define IS_RT_SIGTRAMP(insn1, insn2) \ 55 (/* movel #173,d0; trap #0 */ \ 56 (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \ 57 /* moveq #82,d0; notb d0; trap #0 */ \ 58 || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40)) 59 60 /* Return non-zero if THIS_FRAME corresponds to a signal trampoline. For 61 the sake of m68k_linux_get_sigtramp_info we also distinguish between 62 non-RT and RT signal trampolines. */ 63 64 static int 65 m68k_linux_pc_in_sigtramp (const frame_info_ptr &this_frame) 66 { 67 struct gdbarch *gdbarch = get_frame_arch (this_frame); 68 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 69 gdb_byte buf[12]; 70 unsigned long insn0, insn1, insn2; 71 CORE_ADDR pc = get_frame_pc (this_frame); 72 73 if (!safe_frame_unwind_memory (this_frame, pc - 4, {buf, sizeof (buf)})) 74 return 0; 75 insn1 = extract_unsigned_integer (buf + 4, 4, byte_order); 76 insn2 = extract_unsigned_integer (buf + 8, 4, byte_order); 77 if (IS_SIGTRAMP (insn1, insn2)) 78 return 1; 79 if (IS_RT_SIGTRAMP (insn1, insn2)) 80 return 2; 81 82 insn0 = extract_unsigned_integer (buf, 4, byte_order); 83 if (IS_SIGTRAMP (insn0, insn1)) 84 return 1; 85 if (IS_RT_SIGTRAMP (insn0, insn1)) 86 return 2; 87 88 insn0 = ((insn0 << 16) & 0xffffffff) | (insn1 >> 16); 89 insn1 = ((insn1 << 16) & 0xffffffff) | (insn2 >> 16); 90 if (IS_SIGTRAMP (insn0, insn1)) 91 return 1; 92 if (IS_RT_SIGTRAMP (insn0, insn1)) 93 return 2; 94 95 return 0; 96 } 97 98 /* From <asm/sigcontext.h>. */ 99 static int m68k_linux_sigcontext_reg_offset[M68K_NUM_REGS] = 100 { 101 2 * 4, /* %d0 */ 102 3 * 4, /* %d1 */ 103 -1, /* %d2 */ 104 -1, /* %d3 */ 105 -1, /* %d4 */ 106 -1, /* %d5 */ 107 -1, /* %d6 */ 108 -1, /* %d7 */ 109 4 * 4, /* %a0 */ 110 5 * 4, /* %a1 */ 111 -1, /* %a2 */ 112 -1, /* %a3 */ 113 -1, /* %a4 */ 114 -1, /* %a5 */ 115 -1, /* %fp */ 116 1 * 4, /* %sp */ 117 6 * 4, /* %sr */ 118 6 * 4 + 2, /* %pc */ 119 8 * 4, /* %fp0 */ 120 11 * 4, /* %fp1 */ 121 -1, /* %fp2 */ 122 -1, /* %fp3 */ 123 -1, /* %fp4 */ 124 -1, /* %fp5 */ 125 -1, /* %fp6 */ 126 -1, /* %fp7 */ 127 14 * 4, /* %fpcr */ 128 15 * 4, /* %fpsr */ 129 16 * 4 /* %fpiaddr */ 130 }; 131 132 static int m68k_uclinux_sigcontext_reg_offset[M68K_NUM_REGS] = 133 { 134 2 * 4, /* %d0 */ 135 3 * 4, /* %d1 */ 136 -1, /* %d2 */ 137 -1, /* %d3 */ 138 -1, /* %d4 */ 139 -1, /* %d5 */ 140 -1, /* %d6 */ 141 -1, /* %d7 */ 142 4 * 4, /* %a0 */ 143 5 * 4, /* %a1 */ 144 -1, /* %a2 */ 145 -1, /* %a3 */ 146 -1, /* %a4 */ 147 6 * 4, /* %a5 */ 148 -1, /* %fp */ 149 1 * 4, /* %sp */ 150 7 * 4, /* %sr */ 151 7 * 4 + 2, /* %pc */ 152 -1, /* %fp0 */ 153 -1, /* %fp1 */ 154 -1, /* %fp2 */ 155 -1, /* %fp3 */ 156 -1, /* %fp4 */ 157 -1, /* %fp5 */ 158 -1, /* %fp6 */ 159 -1, /* %fp7 */ 160 -1, /* %fpcr */ 161 -1, /* %fpsr */ 162 -1 /* %fpiaddr */ 163 }; 164 165 /* From <asm/ucontext.h>. */ 166 static int m68k_linux_ucontext_reg_offset[M68K_NUM_REGS] = 167 { 168 6 * 4, /* %d0 */ 169 7 * 4, /* %d1 */ 170 8 * 4, /* %d2 */ 171 9 * 4, /* %d3 */ 172 10 * 4, /* %d4 */ 173 11 * 4, /* %d5 */ 174 12 * 4, /* %d6 */ 175 13 * 4, /* %d7 */ 176 14 * 4, /* %a0 */ 177 15 * 4, /* %a1 */ 178 16 * 4, /* %a2 */ 179 17 * 4, /* %a3 */ 180 18 * 4, /* %a4 */ 181 19 * 4, /* %a5 */ 182 20 * 4, /* %fp */ 183 21 * 4, /* %sp */ 184 23 * 4, /* %sr */ 185 22 * 4, /* %pc */ 186 27 * 4, /* %fp0 */ 187 30 * 4, /* %fp1 */ 188 33 * 4, /* %fp2 */ 189 36 * 4, /* %fp3 */ 190 39 * 4, /* %fp4 */ 191 42 * 4, /* %fp5 */ 192 45 * 4, /* %fp6 */ 193 48 * 4, /* %fp7 */ 194 24 * 4, /* %fpcr */ 195 25 * 4, /* %fpsr */ 196 26 * 4 /* %fpiaddr */ 197 }; 198 199 200 /* Get info about saved registers in sigtramp. */ 201 202 struct m68k_linux_sigtramp_info 203 { 204 /* Address of sigcontext. */ 205 CORE_ADDR sigcontext_addr; 206 207 /* Offset of registers in `struct sigcontext'. */ 208 int *sc_reg_offset; 209 }; 210 211 /* Nonzero if running on uClinux. */ 212 static int target_is_uclinux; 213 214 static void 215 m68k_linux_inferior_created (inferior *inf) 216 { 217 /* Record that we will need to re-evaluate whether we are running on a 218 uClinux or normal GNU/Linux target (see m68k_linux_get_sigtramp_info). */ 219 target_is_uclinux = -1; 220 } 221 222 static struct m68k_linux_sigtramp_info 223 m68k_linux_get_sigtramp_info (const frame_info_ptr &this_frame) 224 { 225 struct gdbarch *gdbarch = get_frame_arch (this_frame); 226 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 227 CORE_ADDR sp; 228 struct m68k_linux_sigtramp_info info; 229 230 /* Determine whether we are running on a uClinux or normal GNU/Linux 231 target so we can use the correct sigcontext layouts. */ 232 if (target_is_uclinux == -1) 233 target_is_uclinux = linux_is_uclinux (); 234 235 sp = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM); 236 237 /* Get sigcontext address, it is the third parameter on the stack. */ 238 info.sigcontext_addr = read_memory_unsigned_integer (sp + 8, 4, byte_order); 239 240 if (m68k_linux_pc_in_sigtramp (this_frame) == 2) 241 info.sc_reg_offset = m68k_linux_ucontext_reg_offset; 242 else 243 info.sc_reg_offset = (target_is_uclinux 244 ? m68k_uclinux_sigcontext_reg_offset 245 : m68k_linux_sigcontext_reg_offset); 246 return info; 247 } 248 249 /* Signal trampolines. */ 250 251 static struct trad_frame_cache * 252 m68k_linux_sigtramp_frame_cache (const frame_info_ptr &this_frame, 253 void **this_cache) 254 { 255 struct frame_id this_id; 256 struct trad_frame_cache *cache; 257 struct gdbarch *gdbarch = get_frame_arch (this_frame); 258 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); 259 struct m68k_linux_sigtramp_info info; 260 gdb_byte buf[4]; 261 int i; 262 263 if (*this_cache) 264 return (struct trad_frame_cache *) *this_cache; 265 266 cache = trad_frame_cache_zalloc (this_frame); 267 268 /* FIXME: cagney/2004-05-01: This is is long standing broken code. 269 The frame ID's code address should be the start-address of the 270 signal trampoline and not the current PC within that 271 trampoline. */ 272 get_frame_register (this_frame, M68K_SP_REGNUM, buf); 273 /* See the end of m68k_push_dummy_call. */ 274 this_id = frame_id_build (extract_unsigned_integer (buf, 4, byte_order) 275 - 4 + 8, get_frame_pc (this_frame)); 276 trad_frame_set_id (cache, this_id); 277 278 info = m68k_linux_get_sigtramp_info (this_frame); 279 280 for (i = 0; i < M68K_NUM_REGS; i++) 281 if (info.sc_reg_offset[i] != -1) 282 trad_frame_set_reg_addr (cache, i, 283 info.sigcontext_addr + info.sc_reg_offset[i]); 284 285 *this_cache = cache; 286 return cache; 287 } 288 289 static void 290 m68k_linux_sigtramp_frame_this_id (const frame_info_ptr &this_frame, 291 void **this_cache, 292 struct frame_id *this_id) 293 { 294 struct trad_frame_cache *cache = 295 m68k_linux_sigtramp_frame_cache (this_frame, this_cache); 296 trad_frame_get_id (cache, this_id); 297 } 298 299 static struct value * 300 m68k_linux_sigtramp_frame_prev_register (const frame_info_ptr &this_frame, 301 void **this_cache, 302 int regnum) 303 { 304 /* Make sure we've initialized the cache. */ 305 struct trad_frame_cache *cache = 306 m68k_linux_sigtramp_frame_cache (this_frame, this_cache); 307 return trad_frame_get_register (cache, this_frame, regnum); 308 } 309 310 static int 311 m68k_linux_sigtramp_frame_sniffer (const struct frame_unwind *self, 312 const frame_info_ptr &this_frame, 313 void **this_prologue_cache) 314 { 315 return m68k_linux_pc_in_sigtramp (this_frame); 316 } 317 318 static const struct frame_unwind m68k_linux_sigtramp_frame_unwind = 319 { 320 "m68k linux sigtramp", 321 SIGTRAMP_FRAME, 322 default_frame_unwind_stop_reason, 323 m68k_linux_sigtramp_frame_this_id, 324 m68k_linux_sigtramp_frame_prev_register, 325 NULL, 326 m68k_linux_sigtramp_frame_sniffer 327 }; 328 329 /* Register maps for supply/collect regset functions. */ 330 331 static const struct regcache_map_entry m68k_linux_gregmap[] = 332 { 333 { 7, M68K_D1_REGNUM, 4 }, /* d1 ... d7 */ 334 { 7, M68K_A0_REGNUM, 4 }, /* a0 ... a6 */ 335 { 1, M68K_D0_REGNUM, 4 }, 336 { 1, M68K_SP_REGNUM, 4 }, 337 { 1, REGCACHE_MAP_SKIP, 4 }, /* orig_d0 (skip) */ 338 { 1, M68K_PS_REGNUM, 4 }, 339 { 1, M68K_PC_REGNUM, 4 }, 340 /* Ignore 16-bit fields 'fmtvec' and '__fill'. */ 341 { 0 } 342 }; 343 344 #define M68K_LINUX_GREGS_SIZE (20 * 4) 345 346 static const struct regcache_map_entry m68k_linux_fpregmap[] = 347 { 348 { 8, M68K_FP0_REGNUM, 12 }, /* fp0 ... fp7 */ 349 { 1, M68K_FPC_REGNUM, 4 }, 350 { 1, M68K_FPS_REGNUM, 4 }, 351 { 1, M68K_FPI_REGNUM, 4 }, 352 { 0 } 353 }; 354 355 #define M68K_LINUX_FPREGS_SIZE (27 * 4) 356 357 /* Register sets. */ 358 359 static const struct regset m68k_linux_gregset = 360 { 361 m68k_linux_gregmap, 362 regcache_supply_regset, regcache_collect_regset 363 }; 364 365 static const struct regset m68k_linux_fpregset = 366 { 367 m68k_linux_fpregmap, 368 regcache_supply_regset, regcache_collect_regset 369 }; 370 371 /* Iterate over core file register note sections. */ 372 373 static void 374 m68k_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, 375 iterate_over_regset_sections_cb *cb, 376 void *cb_data, 377 const struct regcache *regcache) 378 { 379 cb (".reg", M68K_LINUX_GREGS_SIZE, M68K_LINUX_GREGS_SIZE, &m68k_linux_gregset, 380 NULL, cb_data); 381 cb (".reg2", M68K_LINUX_FPREGS_SIZE, M68K_LINUX_FPREGS_SIZE, 382 &m68k_linux_fpregset, NULL, cb_data); 383 } 384 385 static void 386 m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) 387 { 388 m68k_gdbarch_tdep *tdep = gdbarch_tdep<m68k_gdbarch_tdep> (gdbarch); 389 390 linux_init_abi (info, gdbarch, 0); 391 392 tdep->jb_pc = M68K_LINUX_JB_PC; 393 tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE; 394 395 /* GNU/Linux uses a calling convention that's similar to SVR4. It 396 returns integer values in %d0/%d1, pointer values in %a0 and 397 floating values in %fp0, just like SVR4, but uses %a1 to pass the 398 address to store a structure value. It also returns small 399 structures in registers instead of memory. */ 400 m68k_svr4_init_abi (info, gdbarch); 401 tdep->struct_value_regnum = M68K_A1_REGNUM; 402 tdep->struct_return = reg_struct_return; 403 404 set_gdbarch_decr_pc_after_break (gdbarch, 2); 405 406 frame_unwind_append_unwinder (gdbarch, &m68k_linux_sigtramp_frame_unwind); 407 408 /* Shared library handling. */ 409 410 /* GNU/Linux uses SVR4-style shared libraries. */ 411 set_solib_svr4_fetch_link_map_offsets (gdbarch, 412 linux_ilp32_fetch_link_map_offsets); 413 414 /* GNU/Linux uses the dynamic linker included in the GNU C Library. */ 415 set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver); 416 417 set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); 418 419 /* Core file support. */ 420 set_gdbarch_iterate_over_regset_sections 421 (gdbarch, m68k_linux_iterate_over_regset_sections); 422 423 /* Enable TLS support. */ 424 set_gdbarch_fetch_tls_load_module_address (gdbarch, 425 svr4_fetch_objfile_link_map); 426 } 427 428 void _initialize_m68k_linux_tdep (); 429 void 430 _initialize_m68k_linux_tdep () 431 { 432 gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX, 433 m68k_linux_init_abi); 434 gdb::observers::inferior_created.attach (m68k_linux_inferior_created, 435 "m68k-linux-tdep"); 436 } 437
Indexes created Mon Mar 02 05:31:46 UTC 2026