| 1 | /* Target-dependent code for GNU/Linux SPARC. |
| 2 | |
| 3 | Copyright (C) 2003-2019 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 "dwarf2-frame.h" |
| 22 | #include "frame.h" |
| 23 | #include "frame-unwind.h" |
| 24 | #include "gdbtypes.h" |
| 25 | #include "regset.h" |
| 26 | #include "gdbarch.h" |
| 27 | #include "gdbcore.h" |
| 28 | #include "osabi.h" |
| 29 | #include "regcache.h" |
| 30 | #include "solib-svr4.h" |
| 31 | #include "symtab.h" |
| 32 | #include "trad-frame.h" |
| 33 | #include "tramp-frame.h" |
| 34 | #include "xml-syscall.h" |
| 35 | #include "linux-tdep.h" |
| 36 | |
| 37 | /* The syscall's XML filename for sparc 32-bit. */ |
| 38 | #define XML_SYSCALL_FILENAME_SPARC32 "syscalls/sparc-linux.xml" |
| 39 | |
| 40 | #include "sparc-tdep.h" |
| 41 | |
| 42 | /* Signal trampoline support. */ |
| 43 | |
| 44 | static void sparc32_linux_sigframe_init (const struct tramp_frame *self, |
| 45 | struct frame_info *this_frame, |
| 46 | struct trad_frame_cache *this_cache, |
| 47 | CORE_ADDR func); |
| 48 | |
| 49 | /* GNU/Linux has two flavors of signals. Normal signal handlers, and |
| 50 | "realtime" (RT) signals. The RT signals can provide additional |
| 51 | information to the signal handler if the SA_SIGINFO flag is set |
| 52 | when establishing a signal handler using `sigaction'. It is not |
| 53 | unlikely that future versions of GNU/Linux will support SA_SIGINFO |
| 54 | for normal signals too. */ |
| 55 | |
| 56 | /* When the sparc Linux kernel calls a signal handler and the |
| 57 | SA_RESTORER flag isn't set, the return address points to a bit of |
| 58 | code on the stack. This code checks whether the PC appears to be |
| 59 | within this bit of code. |
| 60 | |
| 61 | The instruction sequence for normal signals is encoded below. |
| 62 | Checking for the code sequence should be somewhat reliable, because |
| 63 | the effect is to call the system call sigreturn. This is unlikely |
| 64 | to occur anywhere other than a signal trampoline. */ |
| 65 | |
| 66 | static const struct tramp_frame sparc32_linux_sigframe = |
| 67 | { |
| 68 | SIGTRAMP_FRAME, |
| 69 | 4, |
| 70 | { |
| 71 | { 0x821020d8, ULONGEST_MAX }, /* mov __NR_sigreturn, %g1 */ |
| 72 | { 0x91d02010, ULONGEST_MAX }, /* ta 0x10 */ |
| 73 | { TRAMP_SENTINEL_INSN, ULONGEST_MAX } |
| 74 | }, |
| 75 | sparc32_linux_sigframe_init |
| 76 | }; |
| 77 | |
| 78 | /* The instruction sequence for RT signals is slightly different. The |
| 79 | effect is to call the system call rt_sigreturn. */ |
| 80 | |
| 81 | static const struct tramp_frame sparc32_linux_rt_sigframe = |
| 82 | { |
| 83 | SIGTRAMP_FRAME, |
| 84 | 4, |
| 85 | { |
| 86 | { 0x82102065, ULONGEST_MAX }, /* mov __NR_rt_sigreturn, %g1 */ |
| 87 | { 0x91d02010, ULONGEST_MAX }, /* ta 0x10 */ |
| 88 | { TRAMP_SENTINEL_INSN, ULONGEST_MAX } |
| 89 | }, |
| 90 | sparc32_linux_sigframe_init |
| 91 | }; |
| 92 | |
| 93 | /* This enum represents the signals' numbers on the SPARC |
| 94 | architecture. It just contains the signal definitions which are |
| 95 | different from the generic implementation. |
| 96 | |
| 97 | It is derived from the file <arch/sparc/include/uapi/asm/signal.h>, |
| 98 | from the Linux kernel tree. */ |
| 99 | |
| 100 | enum |
| 101 | { |
| 102 | SPARC_LINUX_SIGEMT = 7, |
| 103 | SPARC_LINUX_SIGBUS = 10, |
| 104 | SPARC_LINUX_SIGSYS = 12, |
| 105 | SPARC_LINUX_SIGURG = 16, |
| 106 | SPARC_LINUX_SIGSTOP = 17, |
| 107 | SPARC_LINUX_SIGTSTP = 18, |
| 108 | SPARC_LINUX_SIGCONT = 19, |
| 109 | SPARC_LINUX_SIGCHLD = 20, |
| 110 | SPARC_LINUX_SIGIO = 23, |
| 111 | SPARC_LINUX_SIGPOLL = SPARC_LINUX_SIGIO, |
| 112 | SPARC_LINUX_SIGLOST = 29, |
| 113 | SPARC_LINUX_SIGPWR = SPARC_LINUX_SIGLOST, |
| 114 | SPARC_LINUX_SIGUSR1 = 30, |
| 115 | SPARC_LINUX_SIGUSR2 = 31, |
| 116 | }; |
| 117 | |
| 118 | static void |
| 119 | sparc32_linux_sigframe_init (const struct tramp_frame *self, |
| 120 | struct frame_info *this_frame, |
| 121 | struct trad_frame_cache *this_cache, |
| 122 | CORE_ADDR func) |
| 123 | { |
| 124 | CORE_ADDR base, addr, sp_addr; |
| 125 | int regnum; |
| 126 | |
| 127 | base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM); |
| 128 | if (self == &sparc32_linux_rt_sigframe) |
| 129 | base += 128; |
| 130 | |
| 131 | /* Offsets from <bits/sigcontext.h>. */ |
| 132 | |
| 133 | trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0); |
| 134 | trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 4); |
| 135 | trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 8); |
| 136 | trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 12); |
| 137 | |
| 138 | /* Since %g0 is always zero, keep the identity encoding. */ |
| 139 | addr = base + 20; |
| 140 | sp_addr = base + 16 + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 4); |
| 141 | for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++) |
| 142 | { |
| 143 | trad_frame_set_reg_addr (this_cache, regnum, addr); |
| 144 | addr += 4; |
| 145 | } |
| 146 | |
| 147 | base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM); |
| 148 | addr = get_frame_memory_unsigned (this_frame, sp_addr, 4); |
| 149 | |
| 150 | for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++) |
| 151 | { |
| 152 | trad_frame_set_reg_addr (this_cache, regnum, addr); |
| 153 | addr += 4; |
| 154 | } |
| 155 | trad_frame_set_id (this_cache, frame_id_build (base, func)); |
| 156 | } |
| 157 | \f |
| 158 | /* Return the address of a system call's alternative return |
| 159 | address. */ |
| 160 | |
| 161 | static CORE_ADDR |
| 162 | sparc32_linux_step_trap (struct frame_info *frame, unsigned long insn) |
| 163 | { |
| 164 | if (insn == 0x91d02010) |
| 165 | { |
| 166 | ULONGEST sc_num = get_frame_register_unsigned (frame, SPARC_G1_REGNUM); |
| 167 | |
| 168 | /* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216. */ |
| 169 | if (sc_num == 101 || sc_num == 216) |
| 170 | { |
| 171 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 172 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 173 | |
| 174 | ULONGEST sp, pc_offset; |
| 175 | |
| 176 | sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM); |
| 177 | |
| 178 | /* The kernel puts the sigreturn registers on the stack, |
| 179 | and this is where the signal unwinding state is take from |
| 180 | when returning from a signal. |
| 181 | |
| 182 | For __NR_sigreturn, this register area sits 96 bytes from |
| 183 | the base of the stack. The saved PC sits 4 bytes into the |
| 184 | sigreturn register save area. |
| 185 | |
| 186 | For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits |
| 187 | right before the sigreturn register save area. */ |
| 188 | |
| 189 | pc_offset = 96 + 4; |
| 190 | if (sc_num == 101) |
| 191 | pc_offset += 128; |
| 192 | |
| 193 | return read_memory_unsigned_integer (sp + pc_offset, 4, byte_order); |
| 194 | } |
| 195 | } |
| 196 | |
| 197 | return 0; |
| 198 | } |
| 199 | \f |
| 200 | |
| 201 | const struct sparc_gregmap sparc32_linux_core_gregmap = |
| 202 | { |
| 203 | 32 * 4, /* %psr */ |
| 204 | 33 * 4, /* %pc */ |
| 205 | 34 * 4, /* %npc */ |
| 206 | 35 * 4, /* %y */ |
| 207 | -1, /* %wim */ |
| 208 | -1, /* %tbr */ |
| 209 | 1 * 4, /* %g1 */ |
| 210 | 16 * 4, /* %l0 */ |
| 211 | 4, /* y size */ |
| 212 | }; |
| 213 | \f |
| 214 | |
| 215 | static void |
| 216 | sparc32_linux_supply_core_gregset (const struct regset *regset, |
| 217 | struct regcache *regcache, |
| 218 | int regnum, const void *gregs, size_t len) |
| 219 | { |
| 220 | sparc32_supply_gregset (&sparc32_linux_core_gregmap, |
| 221 | regcache, regnum, gregs); |
| 222 | } |
| 223 | |
| 224 | static void |
| 225 | sparc32_linux_collect_core_gregset (const struct regset *regset, |
| 226 | const struct regcache *regcache, |
| 227 | int regnum, void *gregs, size_t len) |
| 228 | { |
| 229 | sparc32_collect_gregset (&sparc32_linux_core_gregmap, |
| 230 | regcache, regnum, gregs); |
| 231 | } |
| 232 | |
| 233 | static void |
| 234 | sparc32_linux_supply_core_fpregset (const struct regset *regset, |
| 235 | struct regcache *regcache, |
| 236 | int regnum, const void *fpregs, size_t len) |
| 237 | { |
| 238 | sparc32_supply_fpregset (&sparc32_bsd_fpregmap, regcache, regnum, fpregs); |
| 239 | } |
| 240 | |
| 241 | static void |
| 242 | sparc32_linux_collect_core_fpregset (const struct regset *regset, |
| 243 | const struct regcache *regcache, |
| 244 | int regnum, void *fpregs, size_t len) |
| 245 | { |
| 246 | sparc32_collect_fpregset (&sparc32_bsd_fpregmap, regcache, regnum, fpregs); |
| 247 | } |
| 248 | |
| 249 | /* Set the program counter for process PTID to PC. */ |
| 250 | |
| 251 | #define PSR_SYSCALL 0x00004000 |
| 252 | |
| 253 | static void |
| 254 | sparc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc) |
| 255 | { |
| 256 | struct gdbarch_tdep *tdep = gdbarch_tdep (regcache->arch ()); |
| 257 | ULONGEST psr; |
| 258 | |
| 259 | regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc); |
| 260 | regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4); |
| 261 | |
| 262 | /* Clear the "in syscall" bit to prevent the kernel from |
| 263 | messing with the PCs we just installed, if we happen to be |
| 264 | within an interrupted system call that the kernel wants to |
| 265 | restart. |
| 266 | |
| 267 | Note that after we return from the dummy call, the PSR et al. |
| 268 | registers will be automatically restored, and the kernel |
| 269 | continues to restart the system call at this point. */ |
| 270 | regcache_cooked_read_unsigned (regcache, SPARC32_PSR_REGNUM, &psr); |
| 271 | psr &= ~PSR_SYSCALL; |
| 272 | regcache_cooked_write_unsigned (regcache, SPARC32_PSR_REGNUM, psr); |
| 273 | } |
| 274 | |
| 275 | static LONGEST |
| 276 | sparc32_linux_get_syscall_number (struct gdbarch *gdbarch, |
| 277 | thread_info *thread) |
| 278 | { |
| 279 | struct regcache *regcache = get_thread_regcache (thread); |
| 280 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 281 | /* The content of a register. */ |
| 282 | gdb_byte buf[4]; |
| 283 | /* The result. */ |
| 284 | LONGEST ret; |
| 285 | |
| 286 | /* Getting the system call number from the register. |
| 287 | When dealing with the sparc architecture, this information |
| 288 | is stored at the %g1 register. */ |
| 289 | regcache->cooked_read (SPARC_G1_REGNUM, buf); |
| 290 | |
| 291 | ret = extract_signed_integer (buf, 4, byte_order); |
| 292 | |
| 293 | return ret; |
| 294 | } |
| 295 | |
| 296 | /* Implementation of `gdbarch_gdb_signal_from_target', as defined in |
| 297 | gdbarch.h. */ |
| 298 | |
| 299 | static enum gdb_signal |
| 300 | sparc32_linux_gdb_signal_from_target (struct gdbarch *gdbarch, |
| 301 | int signal) |
| 302 | { |
| 303 | switch (signal) |
| 304 | { |
| 305 | case SPARC_LINUX_SIGEMT: |
| 306 | return GDB_SIGNAL_EMT; |
| 307 | |
| 308 | case SPARC_LINUX_SIGBUS: |
| 309 | return GDB_SIGNAL_BUS; |
| 310 | |
| 311 | case SPARC_LINUX_SIGSYS: |
| 312 | return GDB_SIGNAL_SYS; |
| 313 | |
| 314 | case SPARC_LINUX_SIGURG: |
| 315 | return GDB_SIGNAL_URG; |
| 316 | |
| 317 | case SPARC_LINUX_SIGSTOP: |
| 318 | return GDB_SIGNAL_STOP; |
| 319 | |
| 320 | case SPARC_LINUX_SIGTSTP: |
| 321 | return GDB_SIGNAL_TSTP; |
| 322 | |
| 323 | case SPARC_LINUX_SIGCONT: |
| 324 | return GDB_SIGNAL_CONT; |
| 325 | |
| 326 | case SPARC_LINUX_SIGCHLD: |
| 327 | return GDB_SIGNAL_CHLD; |
| 328 | |
| 329 | /* No way to differentiate between SIGIO and SIGPOLL. |
| 330 | Therefore, we just handle the first one. */ |
| 331 | case SPARC_LINUX_SIGIO: |
| 332 | return GDB_SIGNAL_IO; |
| 333 | |
| 334 | /* No way to differentiate between SIGLOST and SIGPWR. |
| 335 | Therefore, we just handle the first one. */ |
| 336 | case SPARC_LINUX_SIGLOST: |
| 337 | return GDB_SIGNAL_LOST; |
| 338 | |
| 339 | case SPARC_LINUX_SIGUSR1: |
| 340 | return GDB_SIGNAL_USR1; |
| 341 | |
| 342 | case SPARC_LINUX_SIGUSR2: |
| 343 | return GDB_SIGNAL_USR2; |
| 344 | } |
| 345 | |
| 346 | return linux_gdb_signal_from_target (gdbarch, signal); |
| 347 | } |
| 348 | |
| 349 | /* Implementation of `gdbarch_gdb_signal_to_target', as defined in |
| 350 | gdbarch.h. */ |
| 351 | |
| 352 | static int |
| 353 | sparc32_linux_gdb_signal_to_target (struct gdbarch *gdbarch, |
| 354 | enum gdb_signal signal) |
| 355 | { |
| 356 | switch (signal) |
| 357 | { |
| 358 | case GDB_SIGNAL_EMT: |
| 359 | return SPARC_LINUX_SIGEMT; |
| 360 | |
| 361 | case GDB_SIGNAL_BUS: |
| 362 | return SPARC_LINUX_SIGBUS; |
| 363 | |
| 364 | case GDB_SIGNAL_SYS: |
| 365 | return SPARC_LINUX_SIGSYS; |
| 366 | |
| 367 | case GDB_SIGNAL_URG: |
| 368 | return SPARC_LINUX_SIGURG; |
| 369 | |
| 370 | case GDB_SIGNAL_STOP: |
| 371 | return SPARC_LINUX_SIGSTOP; |
| 372 | |
| 373 | case GDB_SIGNAL_TSTP: |
| 374 | return SPARC_LINUX_SIGTSTP; |
| 375 | |
| 376 | case GDB_SIGNAL_CONT: |
| 377 | return SPARC_LINUX_SIGCONT; |
| 378 | |
| 379 | case GDB_SIGNAL_CHLD: |
| 380 | return SPARC_LINUX_SIGCHLD; |
| 381 | |
| 382 | case GDB_SIGNAL_IO: |
| 383 | return SPARC_LINUX_SIGIO; |
| 384 | |
| 385 | case GDB_SIGNAL_POLL: |
| 386 | return SPARC_LINUX_SIGPOLL; |
| 387 | |
| 388 | case GDB_SIGNAL_LOST: |
| 389 | return SPARC_LINUX_SIGLOST; |
| 390 | |
| 391 | case GDB_SIGNAL_PWR: |
| 392 | return SPARC_LINUX_SIGPWR; |
| 393 | |
| 394 | case GDB_SIGNAL_USR1: |
| 395 | return SPARC_LINUX_SIGUSR1; |
| 396 | |
| 397 | case GDB_SIGNAL_USR2: |
| 398 | return SPARC_LINUX_SIGUSR2; |
| 399 | } |
| 400 | |
| 401 | return linux_gdb_signal_to_target (gdbarch, signal); |
| 402 | } |
| 403 | |
| 404 | \f |
| 405 | |
| 406 | static const struct regset sparc32_linux_gregset = |
| 407 | { |
| 408 | NULL, |
| 409 | sparc32_linux_supply_core_gregset, |
| 410 | sparc32_linux_collect_core_gregset |
| 411 | }; |
| 412 | |
| 413 | static const struct regset sparc32_linux_fpregset = |
| 414 | { |
| 415 | NULL, |
| 416 | sparc32_linux_supply_core_fpregset, |
| 417 | sparc32_linux_collect_core_fpregset |
| 418 | }; |
| 419 | |
| 420 | static void |
| 421 | sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 422 | { |
| 423 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 424 | |
| 425 | linux_init_abi (info, gdbarch); |
| 426 | |
| 427 | tdep->gregset = &sparc32_linux_gregset; |
| 428 | tdep->sizeof_gregset = 152; |
| 429 | |
| 430 | tdep->fpregset = &sparc32_linux_fpregset; |
| 431 | tdep->sizeof_fpregset = 396; |
| 432 | |
| 433 | tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_sigframe); |
| 434 | tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_rt_sigframe); |
| 435 | |
| 436 | /* GNU/Linux has SVR4-style shared libraries... */ |
| 437 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| 438 | set_solib_svr4_fetch_link_map_offsets |
| 439 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
| 440 | |
| 441 | /* ...which means that we need some special handling when doing |
| 442 | prologue analysis. */ |
| 443 | tdep->plt_entry_size = 12; |
| 444 | |
| 445 | /* Enable TLS support. */ |
| 446 | set_gdbarch_fetch_tls_load_module_address (gdbarch, |
| 447 | svr4_fetch_objfile_link_map); |
| 448 | |
| 449 | /* Make sure we can single-step over signal return system calls. */ |
| 450 | tdep->step_trap = sparc32_linux_step_trap; |
| 451 | |
| 452 | /* Hook in the DWARF CFI frame unwinder. */ |
| 453 | dwarf2_append_unwinders (gdbarch); |
| 454 | |
| 455 | set_gdbarch_write_pc (gdbarch, sparc_linux_write_pc); |
| 456 | |
| 457 | /* Functions for 'catch syscall'. */ |
| 458 | set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_SPARC32); |
| 459 | set_gdbarch_get_syscall_number (gdbarch, |
| 460 | sparc32_linux_get_syscall_number); |
| 461 | |
| 462 | set_gdbarch_gdb_signal_from_target (gdbarch, |
| 463 | sparc32_linux_gdb_signal_from_target); |
| 464 | set_gdbarch_gdb_signal_to_target (gdbarch, |
| 465 | sparc32_linux_gdb_signal_to_target); |
| 466 | } |
| 467 | |
| 468 | void |
| 469 | _initialize_sparc_linux_tdep (void) |
| 470 | { |
| 471 | gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_LINUX, |
| 472 | sparc32_linux_init_abi); |
| 473 | } |