| 1 | /* Target-dependent code for GNU/Linux AArch64. |
| 2 | |
| 3 | Copyright (C) 2009-2014 Free Software Foundation, Inc. |
| 4 | Contributed by ARM Ltd. |
| 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 | |
| 23 | #include "gdbarch.h" |
| 24 | #include "glibc-tdep.h" |
| 25 | #include "linux-tdep.h" |
| 26 | #include "aarch64-tdep.h" |
| 27 | #include "aarch64-linux-tdep.h" |
| 28 | #include "osabi.h" |
| 29 | #include "solib-svr4.h" |
| 30 | #include "symtab.h" |
| 31 | #include "tramp-frame.h" |
| 32 | #include "trad-frame.h" |
| 33 | |
| 34 | #include "inferior.h" |
| 35 | #include "regcache.h" |
| 36 | #include "regset.h" |
| 37 | |
| 38 | #include "cli/cli-utils.h" |
| 39 | #include "stap-probe.h" |
| 40 | #include "parser-defs.h" |
| 41 | #include "user-regs.h" |
| 42 | #include <ctype.h> |
| 43 | |
| 44 | /* The general-purpose regset consists of 31 X registers, plus SP, PC, |
| 45 | and PSTATE registers, as defined in the AArch64 port of the Linux |
| 46 | kernel. */ |
| 47 | #define AARCH64_LINUX_SIZEOF_GREGSET (34 * X_REGISTER_SIZE) |
| 48 | |
| 49 | /* The fp regset consists of 32 V registers, plus FPCR and FPSR which |
| 50 | are 4 bytes wide each, and the whole structure is padded to 128 bit |
| 51 | alignment. */ |
| 52 | #define AARCH64_LINUX_SIZEOF_FPREGSET (33 * V_REGISTER_SIZE) |
| 53 | |
| 54 | /* Signal frame handling. |
| 55 | |
| 56 | +----------+ ^ |
| 57 | | saved lr | | |
| 58 | +->| saved fp |--+ |
| 59 | | | | |
| 60 | | | | |
| 61 | | +----------+ |
| 62 | | | saved lr | |
| 63 | +--| saved fp | |
| 64 | ^ | | |
| 65 | | | | |
| 66 | | +----------+ |
| 67 | ^ | | |
| 68 | | | signal | |
| 69 | | | | |
| 70 | | | saved lr |-->interrupted_function_pc |
| 71 | +--| saved fp | |
| 72 | | +----------+ |
| 73 | | | saved lr |--> default_restorer (movz x8, NR_sys_rt_sigreturn; svc 0) |
| 74 | +--| saved fp |<- FP |
| 75 | | | |
| 76 | | |<- SP |
| 77 | +----------+ |
| 78 | |
| 79 | On signal delivery, the kernel will create a signal handler stack |
| 80 | frame and setup the return address in LR to point at restorer stub. |
| 81 | The signal stack frame is defined by: |
| 82 | |
| 83 | struct rt_sigframe |
| 84 | { |
| 85 | siginfo_t info; |
| 86 | struct ucontext uc; |
| 87 | }; |
| 88 | |
| 89 | typedef struct |
| 90 | { |
| 91 | ... 128 bytes |
| 92 | } siginfo_t; |
| 93 | |
| 94 | The ucontext has the following form: |
| 95 | struct ucontext |
| 96 | { |
| 97 | unsigned long uc_flags; |
| 98 | struct ucontext *uc_link; |
| 99 | stack_t uc_stack; |
| 100 | sigset_t uc_sigmask; |
| 101 | struct sigcontext uc_mcontext; |
| 102 | }; |
| 103 | |
| 104 | typedef struct sigaltstack |
| 105 | { |
| 106 | void *ss_sp; |
| 107 | int ss_flags; |
| 108 | size_t ss_size; |
| 109 | } stack_t; |
| 110 | |
| 111 | struct sigcontext |
| 112 | { |
| 113 | unsigned long fault_address; |
| 114 | unsigned long regs[31]; |
| 115 | unsigned long sp; / * 31 * / |
| 116 | unsigned long pc; / * 32 * / |
| 117 | unsigned long pstate; / * 33 * / |
| 118 | __u8 __reserved[4096] |
| 119 | }; |
| 120 | |
| 121 | The restorer stub will always have the form: |
| 122 | |
| 123 | d28015a8 movz x8, #0xad |
| 124 | d4000001 svc #0x0 |
| 125 | |
| 126 | We detect signal frames by snooping the return code for the restorer |
| 127 | instruction sequence. |
| 128 | |
| 129 | The handler then needs to recover the saved register set from |
| 130 | ucontext.uc_mcontext. */ |
| 131 | |
| 132 | /* These magic numbers need to reflect the layout of the kernel |
| 133 | defined struct rt_sigframe and ucontext. */ |
| 134 | #define AARCH64_SIGCONTEXT_REG_SIZE 8 |
| 135 | #define AARCH64_RT_SIGFRAME_UCONTEXT_OFFSET 128 |
| 136 | #define AARCH64_UCONTEXT_SIGCONTEXT_OFFSET 176 |
| 137 | #define AARCH64_SIGCONTEXT_XO_OFFSET 8 |
| 138 | |
| 139 | /* Implement the "init" method of struct tramp_frame. */ |
| 140 | |
| 141 | static void |
| 142 | aarch64_linux_sigframe_init (const struct tramp_frame *self, |
| 143 | struct frame_info *this_frame, |
| 144 | struct trad_frame_cache *this_cache, |
| 145 | CORE_ADDR func) |
| 146 | { |
| 147 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| 148 | CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM); |
| 149 | CORE_ADDR fp = get_frame_register_unsigned (this_frame, AARCH64_FP_REGNUM); |
| 150 | CORE_ADDR sigcontext_addr = |
| 151 | sp |
| 152 | + AARCH64_RT_SIGFRAME_UCONTEXT_OFFSET |
| 153 | + AARCH64_UCONTEXT_SIGCONTEXT_OFFSET; |
| 154 | int i; |
| 155 | |
| 156 | for (i = 0; i < 31; i++) |
| 157 | { |
| 158 | trad_frame_set_reg_addr (this_cache, |
| 159 | AARCH64_X0_REGNUM + i, |
| 160 | sigcontext_addr + AARCH64_SIGCONTEXT_XO_OFFSET |
| 161 | + i * AARCH64_SIGCONTEXT_REG_SIZE); |
| 162 | } |
| 163 | |
| 164 | trad_frame_set_reg_addr (this_cache, AARCH64_FP_REGNUM, fp); |
| 165 | trad_frame_set_reg_addr (this_cache, AARCH64_LR_REGNUM, fp + 8); |
| 166 | trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM, fp + 8); |
| 167 | |
| 168 | trad_frame_set_id (this_cache, frame_id_build (fp, func)); |
| 169 | } |
| 170 | |
| 171 | static const struct tramp_frame aarch64_linux_rt_sigframe = |
| 172 | { |
| 173 | SIGTRAMP_FRAME, |
| 174 | 4, |
| 175 | { |
| 176 | /* movz x8, 0x8b (S=1,o=10,h=0,i=0x8b,r=8) |
| 177 | Soo1 0010 1hhi iiii iiii iiii iiir rrrr */ |
| 178 | {0xd2801168, -1}, |
| 179 | |
| 180 | /* svc 0x0 (o=0, l=1) |
| 181 | 1101 0100 oooi iiii iiii iiii iii0 00ll */ |
| 182 | {0xd4000001, -1}, |
| 183 | {TRAMP_SENTINEL_INSN, -1} |
| 184 | }, |
| 185 | aarch64_linux_sigframe_init |
| 186 | }; |
| 187 | |
| 188 | /* Fill GDB's register array with the general-purpose register values |
| 189 | in the buffer pointed by GREGS_BUF. */ |
| 190 | |
| 191 | void |
| 192 | aarch64_linux_supply_gregset (struct regcache *regcache, |
| 193 | const gdb_byte *gregs_buf) |
| 194 | { |
| 195 | int regno; |
| 196 | |
| 197 | for (regno = AARCH64_X0_REGNUM; regno <= AARCH64_CPSR_REGNUM; regno++) |
| 198 | regcache_raw_supply (regcache, regno, |
| 199 | gregs_buf + X_REGISTER_SIZE |
| 200 | * (regno - AARCH64_X0_REGNUM)); |
| 201 | } |
| 202 | |
| 203 | /* The "supply_regset" function for the general-purpose register set. */ |
| 204 | |
| 205 | static void |
| 206 | supply_gregset_from_core (const struct regset *regset, |
| 207 | struct regcache *regcache, |
| 208 | int regnum, const void *regbuf, size_t len) |
| 209 | { |
| 210 | aarch64_linux_supply_gregset (regcache, (const gdb_byte *) regbuf); |
| 211 | } |
| 212 | |
| 213 | /* Fill GDB's register array with the floating-point register values |
| 214 | in the buffer pointed by FPREGS_BUF. */ |
| 215 | |
| 216 | void |
| 217 | aarch64_linux_supply_fpregset (struct regcache *regcache, |
| 218 | const gdb_byte *fpregs_buf) |
| 219 | { |
| 220 | int regno; |
| 221 | |
| 222 | for (regno = AARCH64_V0_REGNUM; regno <= AARCH64_V31_REGNUM; regno++) |
| 223 | regcache_raw_supply (regcache, regno, |
| 224 | fpregs_buf + V_REGISTER_SIZE |
| 225 | * (regno - AARCH64_V0_REGNUM)); |
| 226 | |
| 227 | regcache_raw_supply (regcache, AARCH64_FPSR_REGNUM, |
| 228 | fpregs_buf + V_REGISTER_SIZE * 32); |
| 229 | regcache_raw_supply (regcache, AARCH64_FPCR_REGNUM, |
| 230 | fpregs_buf + V_REGISTER_SIZE * 32 + 4); |
| 231 | } |
| 232 | |
| 233 | /* The "supply_regset" function for the floating-point register set. */ |
| 234 | |
| 235 | static void |
| 236 | supply_fpregset_from_core (const struct regset *regset, |
| 237 | struct regcache *regcache, |
| 238 | int regnum, const void *regbuf, size_t len) |
| 239 | { |
| 240 | aarch64_linux_supply_fpregset (regcache, (const gdb_byte *) regbuf); |
| 241 | } |
| 242 | |
| 243 | /* Implement the "regset_from_core_section" gdbarch method. */ |
| 244 | |
| 245 | static const struct regset * |
| 246 | aarch64_linux_regset_from_core_section (struct gdbarch *gdbarch, |
| 247 | const char *sect_name, |
| 248 | size_t sect_size) |
| 249 | { |
| 250 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 251 | |
| 252 | if (strcmp (sect_name, ".reg") == 0 |
| 253 | && sect_size == AARCH64_LINUX_SIZEOF_GREGSET) |
| 254 | { |
| 255 | if (tdep->gregset == NULL) |
| 256 | tdep->gregset = regset_alloc (gdbarch, supply_gregset_from_core, |
| 257 | NULL); |
| 258 | return tdep->gregset; |
| 259 | } |
| 260 | |
| 261 | if (strcmp (sect_name, ".reg2") == 0 |
| 262 | && sect_size == AARCH64_LINUX_SIZEOF_FPREGSET) |
| 263 | { |
| 264 | if (tdep->fpregset == NULL) |
| 265 | tdep->fpregset = regset_alloc (gdbarch, supply_fpregset_from_core, |
| 266 | NULL); |
| 267 | return tdep->fpregset; |
| 268 | } |
| 269 | return NULL; |
| 270 | } |
| 271 | |
| 272 | /* Implementation of `gdbarch_stap_is_single_operand', as defined in |
| 273 | gdbarch.h. */ |
| 274 | |
| 275 | static int |
| 276 | aarch64_stap_is_single_operand (struct gdbarch *gdbarch, const char *s) |
| 277 | { |
| 278 | return (*s == '#' || isdigit (*s) /* Literal number. */ |
| 279 | || *s == '[' /* Register indirection. */ |
| 280 | || isalpha (*s)); /* Register value. */ |
| 281 | } |
| 282 | |
| 283 | /* This routine is used to parse a special token in AArch64's assembly. |
| 284 | |
| 285 | The special tokens parsed by it are: |
| 286 | |
| 287 | - Register displacement (e.g, [fp, #-8]) |
| 288 | |
| 289 | It returns one if the special token has been parsed successfully, |
| 290 | or zero if the current token is not considered special. */ |
| 291 | |
| 292 | static int |
| 293 | aarch64_stap_parse_special_token (struct gdbarch *gdbarch, |
| 294 | struct stap_parse_info *p) |
| 295 | { |
| 296 | if (*p->arg == '[') |
| 297 | { |
| 298 | /* Temporary holder for lookahead. */ |
| 299 | const char *tmp = p->arg; |
| 300 | char *endp; |
| 301 | /* Used to save the register name. */ |
| 302 | const char *start; |
| 303 | char *regname; |
| 304 | int len; |
| 305 | int got_minus = 0; |
| 306 | long displacement; |
| 307 | struct stoken str; |
| 308 | |
| 309 | ++tmp; |
| 310 | start = tmp; |
| 311 | |
| 312 | /* Register name. */ |
| 313 | while (isalnum (*tmp)) |
| 314 | ++tmp; |
| 315 | |
| 316 | if (*tmp != ',') |
| 317 | return 0; |
| 318 | |
| 319 | len = tmp - start; |
| 320 | regname = alloca (len + 2); |
| 321 | |
| 322 | strncpy (regname, start, len); |
| 323 | regname[len] = '\0'; |
| 324 | |
| 325 | if (user_reg_map_name_to_regnum (gdbarch, regname, len) == -1) |
| 326 | error (_("Invalid register name `%s' on expression `%s'."), |
| 327 | regname, p->saved_arg); |
| 328 | |
| 329 | ++tmp; |
| 330 | tmp = skip_spaces_const (tmp); |
| 331 | /* Now we expect a number. It can begin with '#' or simply |
| 332 | a digit. */ |
| 333 | if (*tmp == '#') |
| 334 | ++tmp; |
| 335 | |
| 336 | if (*tmp == '-') |
| 337 | { |
| 338 | ++tmp; |
| 339 | got_minus = 1; |
| 340 | } |
| 341 | else if (*tmp == '+') |
| 342 | ++tmp; |
| 343 | |
| 344 | if (!isdigit (*tmp)) |
| 345 | return 0; |
| 346 | |
| 347 | displacement = strtol (tmp, &endp, 10); |
| 348 | tmp = endp; |
| 349 | |
| 350 | /* Skipping last `]'. */ |
| 351 | if (*tmp++ != ']') |
| 352 | return 0; |
| 353 | |
| 354 | /* The displacement. */ |
| 355 | write_exp_elt_opcode (OP_LONG); |
| 356 | write_exp_elt_type (builtin_type (gdbarch)->builtin_long); |
| 357 | write_exp_elt_longcst (displacement); |
| 358 | write_exp_elt_opcode (OP_LONG); |
| 359 | if (got_minus) |
| 360 | write_exp_elt_opcode (UNOP_NEG); |
| 361 | |
| 362 | /* The register name. */ |
| 363 | write_exp_elt_opcode (OP_REGISTER); |
| 364 | str.ptr = regname; |
| 365 | str.length = len; |
| 366 | write_exp_string (str); |
| 367 | write_exp_elt_opcode (OP_REGISTER); |
| 368 | |
| 369 | write_exp_elt_opcode (BINOP_ADD); |
| 370 | |
| 371 | /* Casting to the expected type. */ |
| 372 | write_exp_elt_opcode (UNOP_CAST); |
| 373 | write_exp_elt_type (lookup_pointer_type (p->arg_type)); |
| 374 | write_exp_elt_opcode (UNOP_CAST); |
| 375 | |
| 376 | write_exp_elt_opcode (UNOP_IND); |
| 377 | |
| 378 | p->arg = tmp; |
| 379 | } |
| 380 | else |
| 381 | return 0; |
| 382 | |
| 383 | return 1; |
| 384 | } |
| 385 | |
| 386 | static void |
| 387 | aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 388 | { |
| 389 | static const char *const stap_integer_prefixes[] = { "#", "", NULL }; |
| 390 | static const char *const stap_register_prefixes[] = { "", NULL }; |
| 391 | static const char *const stap_register_indirection_prefixes[] = { "[", |
| 392 | NULL }; |
| 393 | static const char *const stap_register_indirection_suffixes[] = { "]", |
| 394 | NULL }; |
| 395 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 396 | |
| 397 | tdep->lowest_pc = 0x8000; |
| 398 | |
| 399 | linux_init_abi (info, gdbarch); |
| 400 | |
| 401 | set_solib_svr4_fetch_link_map_offsets (gdbarch, |
| 402 | svr4_lp64_fetch_link_map_offsets); |
| 403 | |
| 404 | /* Enable TLS support. */ |
| 405 | set_gdbarch_fetch_tls_load_module_address (gdbarch, |
| 406 | svr4_fetch_objfile_link_map); |
| 407 | |
| 408 | /* Shared library handling. */ |
| 409 | set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); |
| 410 | |
| 411 | set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type); |
| 412 | tramp_frame_prepend_unwinder (gdbarch, &aarch64_linux_rt_sigframe); |
| 413 | |
| 414 | /* Enable longjmp. */ |
| 415 | tdep->jb_pc = 11; |
| 416 | |
| 417 | set_gdbarch_regset_from_core_section (gdbarch, |
| 418 | aarch64_linux_regset_from_core_section); |
| 419 | |
| 420 | /* SystemTap related. */ |
| 421 | set_gdbarch_stap_integer_prefixes (gdbarch, stap_integer_prefixes); |
| 422 | set_gdbarch_stap_register_prefixes (gdbarch, stap_register_prefixes); |
| 423 | set_gdbarch_stap_register_indirection_prefixes (gdbarch, |
| 424 | stap_register_indirection_prefixes); |
| 425 | set_gdbarch_stap_register_indirection_suffixes (gdbarch, |
| 426 | stap_register_indirection_suffixes); |
| 427 | set_gdbarch_stap_is_single_operand (gdbarch, aarch64_stap_is_single_operand); |
| 428 | set_gdbarch_stap_parse_special_token (gdbarch, |
| 429 | aarch64_stap_parse_special_token); |
| 430 | } |
| 431 | |
| 432 | /* Provide a prototype to silence -Wmissing-prototypes. */ |
| 433 | extern initialize_file_ftype _initialize_aarch64_linux_tdep; |
| 434 | |
| 435 | void |
| 436 | _initialize_aarch64_linux_tdep (void) |
| 437 | { |
| 438 | gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_LINUX, |
| 439 | aarch64_linux_init_abi); |
| 440 | } |