| 1 | /* Target-dependent code for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright 2001, 2002, 2003, 2004, 2005 Free Software Foundation, |
| 4 | Inc. |
| 5 | |
| 6 | Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com) |
| 7 | for IBM Deutschland Entwicklung GmbH, IBM Corporation. |
| 8 | |
| 9 | This file is part of GDB. |
| 10 | |
| 11 | This program is free software; you can redistribute it and/or modify |
| 12 | it under the terms of the GNU General Public License as published by |
| 13 | the Free Software Foundation; either version 2 of the License, or |
| 14 | (at your option) any later version. |
| 15 | |
| 16 | This program is distributed in the hope that it will be useful, |
| 17 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | GNU General Public License for more details. |
| 20 | |
| 21 | You should have received a copy of the GNU General Public License |
| 22 | along with this program; if not, write to the Free Software |
| 23 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
| 24 | 02111-1307, USA. */ |
| 25 | |
| 26 | #include "defs.h" |
| 27 | #include "arch-utils.h" |
| 28 | #include "frame.h" |
| 29 | #include "inferior.h" |
| 30 | #include "symtab.h" |
| 31 | #include "target.h" |
| 32 | #include "gdbcore.h" |
| 33 | #include "gdbcmd.h" |
| 34 | #include "objfiles.h" |
| 35 | #include "tm.h" |
| 36 | #include "../bfd/bfd.h" |
| 37 | #include "floatformat.h" |
| 38 | #include "regcache.h" |
| 39 | #include "trad-frame.h" |
| 40 | #include "frame-base.h" |
| 41 | #include "frame-unwind.h" |
| 42 | #include "dwarf2-frame.h" |
| 43 | #include "reggroups.h" |
| 44 | #include "regset.h" |
| 45 | #include "value.h" |
| 46 | #include "gdb_assert.h" |
| 47 | #include "dis-asm.h" |
| 48 | #include "solib-svr4.h" /* For struct link_map_offsets. */ |
| 49 | |
| 50 | #include "s390-tdep.h" |
| 51 | |
| 52 | |
| 53 | /* The tdep structure. */ |
| 54 | |
| 55 | struct gdbarch_tdep |
| 56 | { |
| 57 | /* ABI version. */ |
| 58 | enum { ABI_LINUX_S390, ABI_LINUX_ZSERIES } abi; |
| 59 | |
| 60 | /* Core file register sets. */ |
| 61 | const struct regset *gregset; |
| 62 | int sizeof_gregset; |
| 63 | |
| 64 | const struct regset *fpregset; |
| 65 | int sizeof_fpregset; |
| 66 | }; |
| 67 | |
| 68 | |
| 69 | /* Register information. */ |
| 70 | |
| 71 | struct s390_register_info |
| 72 | { |
| 73 | char *name; |
| 74 | struct type **type; |
| 75 | }; |
| 76 | |
| 77 | static struct s390_register_info s390_register_info[S390_NUM_TOTAL_REGS] = |
| 78 | { |
| 79 | /* Program Status Word. */ |
| 80 | { "pswm", &builtin_type_long }, |
| 81 | { "pswa", &builtin_type_long }, |
| 82 | |
| 83 | /* General Purpose Registers. */ |
| 84 | { "r0", &builtin_type_long }, |
| 85 | { "r1", &builtin_type_long }, |
| 86 | { "r2", &builtin_type_long }, |
| 87 | { "r3", &builtin_type_long }, |
| 88 | { "r4", &builtin_type_long }, |
| 89 | { "r5", &builtin_type_long }, |
| 90 | { "r6", &builtin_type_long }, |
| 91 | { "r7", &builtin_type_long }, |
| 92 | { "r8", &builtin_type_long }, |
| 93 | { "r9", &builtin_type_long }, |
| 94 | { "r10", &builtin_type_long }, |
| 95 | { "r11", &builtin_type_long }, |
| 96 | { "r12", &builtin_type_long }, |
| 97 | { "r13", &builtin_type_long }, |
| 98 | { "r14", &builtin_type_long }, |
| 99 | { "r15", &builtin_type_long }, |
| 100 | |
| 101 | /* Access Registers. */ |
| 102 | { "acr0", &builtin_type_int }, |
| 103 | { "acr1", &builtin_type_int }, |
| 104 | { "acr2", &builtin_type_int }, |
| 105 | { "acr3", &builtin_type_int }, |
| 106 | { "acr4", &builtin_type_int }, |
| 107 | { "acr5", &builtin_type_int }, |
| 108 | { "acr6", &builtin_type_int }, |
| 109 | { "acr7", &builtin_type_int }, |
| 110 | { "acr8", &builtin_type_int }, |
| 111 | { "acr9", &builtin_type_int }, |
| 112 | { "acr10", &builtin_type_int }, |
| 113 | { "acr11", &builtin_type_int }, |
| 114 | { "acr12", &builtin_type_int }, |
| 115 | { "acr13", &builtin_type_int }, |
| 116 | { "acr14", &builtin_type_int }, |
| 117 | { "acr15", &builtin_type_int }, |
| 118 | |
| 119 | /* Floating Point Control Word. */ |
| 120 | { "fpc", &builtin_type_int }, |
| 121 | |
| 122 | /* Floating Point Registers. */ |
| 123 | { "f0", &builtin_type_double }, |
| 124 | { "f1", &builtin_type_double }, |
| 125 | { "f2", &builtin_type_double }, |
| 126 | { "f3", &builtin_type_double }, |
| 127 | { "f4", &builtin_type_double }, |
| 128 | { "f5", &builtin_type_double }, |
| 129 | { "f6", &builtin_type_double }, |
| 130 | { "f7", &builtin_type_double }, |
| 131 | { "f8", &builtin_type_double }, |
| 132 | { "f9", &builtin_type_double }, |
| 133 | { "f10", &builtin_type_double }, |
| 134 | { "f11", &builtin_type_double }, |
| 135 | { "f12", &builtin_type_double }, |
| 136 | { "f13", &builtin_type_double }, |
| 137 | { "f14", &builtin_type_double }, |
| 138 | { "f15", &builtin_type_double }, |
| 139 | |
| 140 | /* Pseudo registers. */ |
| 141 | { "pc", &builtin_type_void_func_ptr }, |
| 142 | { "cc", &builtin_type_int }, |
| 143 | }; |
| 144 | |
| 145 | /* Return the name of register REGNUM. */ |
| 146 | static const char * |
| 147 | s390_register_name (int regnum) |
| 148 | { |
| 149 | gdb_assert (regnum >= 0 && regnum < S390_NUM_TOTAL_REGS); |
| 150 | return s390_register_info[regnum].name; |
| 151 | } |
| 152 | |
| 153 | /* Return the GDB type object for the "standard" data type of data in |
| 154 | register REGNUM. */ |
| 155 | static struct type * |
| 156 | s390_register_type (struct gdbarch *gdbarch, int regnum) |
| 157 | { |
| 158 | gdb_assert (regnum >= 0 && regnum < S390_NUM_TOTAL_REGS); |
| 159 | return *s390_register_info[regnum].type; |
| 160 | } |
| 161 | |
| 162 | /* DWARF Register Mapping. */ |
| 163 | |
| 164 | static int s390_dwarf_regmap[] = |
| 165 | { |
| 166 | /* General Purpose Registers. */ |
| 167 | S390_R0_REGNUM, S390_R1_REGNUM, S390_R2_REGNUM, S390_R3_REGNUM, |
| 168 | S390_R4_REGNUM, S390_R5_REGNUM, S390_R6_REGNUM, S390_R7_REGNUM, |
| 169 | S390_R8_REGNUM, S390_R9_REGNUM, S390_R10_REGNUM, S390_R11_REGNUM, |
| 170 | S390_R12_REGNUM, S390_R13_REGNUM, S390_R14_REGNUM, S390_R15_REGNUM, |
| 171 | |
| 172 | /* Floating Point Registers. */ |
| 173 | S390_F0_REGNUM, S390_F2_REGNUM, S390_F4_REGNUM, S390_F6_REGNUM, |
| 174 | S390_F1_REGNUM, S390_F3_REGNUM, S390_F5_REGNUM, S390_F7_REGNUM, |
| 175 | S390_F8_REGNUM, S390_F10_REGNUM, S390_F12_REGNUM, S390_F14_REGNUM, |
| 176 | S390_F9_REGNUM, S390_F11_REGNUM, S390_F13_REGNUM, S390_F15_REGNUM, |
| 177 | |
| 178 | /* Control Registers (not mapped). */ |
| 179 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 180 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 181 | |
| 182 | /* Access Registers. */ |
| 183 | S390_A0_REGNUM, S390_A1_REGNUM, S390_A2_REGNUM, S390_A3_REGNUM, |
| 184 | S390_A4_REGNUM, S390_A5_REGNUM, S390_A6_REGNUM, S390_A7_REGNUM, |
| 185 | S390_A8_REGNUM, S390_A9_REGNUM, S390_A10_REGNUM, S390_A11_REGNUM, |
| 186 | S390_A12_REGNUM, S390_A13_REGNUM, S390_A14_REGNUM, S390_A15_REGNUM, |
| 187 | |
| 188 | /* Program Status Word. */ |
| 189 | S390_PSWM_REGNUM, |
| 190 | S390_PSWA_REGNUM |
| 191 | }; |
| 192 | |
| 193 | /* Convert DWARF register number REG to the appropriate register |
| 194 | number used by GDB. */ |
| 195 | static int |
| 196 | s390_dwarf_reg_to_regnum (int reg) |
| 197 | { |
| 198 | int regnum = -1; |
| 199 | |
| 200 | if (reg >= 0 && reg < ARRAY_SIZE (s390_dwarf_regmap)) |
| 201 | regnum = s390_dwarf_regmap[reg]; |
| 202 | |
| 203 | if (regnum == -1) |
| 204 | warning (_("Unmapped DWARF Register #%d encountered."), reg); |
| 205 | |
| 206 | return regnum; |
| 207 | } |
| 208 | |
| 209 | /* Pseudo registers - PC and condition code. */ |
| 210 | |
| 211 | static void |
| 212 | s390_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache, |
| 213 | int regnum, void *buf) |
| 214 | { |
| 215 | ULONGEST val; |
| 216 | |
| 217 | switch (regnum) |
| 218 | { |
| 219 | case S390_PC_REGNUM: |
| 220 | regcache_raw_read_unsigned (regcache, S390_PSWA_REGNUM, &val); |
| 221 | store_unsigned_integer (buf, 4, val & 0x7fffffff); |
| 222 | break; |
| 223 | |
| 224 | case S390_CC_REGNUM: |
| 225 | regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &val); |
| 226 | store_unsigned_integer (buf, 4, (val >> 12) & 3); |
| 227 | break; |
| 228 | |
| 229 | default: |
| 230 | internal_error (__FILE__, __LINE__, _("invalid regnum")); |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | static void |
| 235 | s390_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache, |
| 236 | int regnum, const void *buf) |
| 237 | { |
| 238 | ULONGEST val, psw; |
| 239 | |
| 240 | switch (regnum) |
| 241 | { |
| 242 | case S390_PC_REGNUM: |
| 243 | val = extract_unsigned_integer (buf, 4); |
| 244 | regcache_raw_read_unsigned (regcache, S390_PSWA_REGNUM, &psw); |
| 245 | psw = (psw & 0x80000000) | (val & 0x7fffffff); |
| 246 | regcache_raw_write_unsigned (regcache, S390_PSWA_REGNUM, psw); |
| 247 | break; |
| 248 | |
| 249 | case S390_CC_REGNUM: |
| 250 | val = extract_unsigned_integer (buf, 4); |
| 251 | regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &psw); |
| 252 | psw = (psw & ~((ULONGEST)3 << 12)) | ((val & 3) << 12); |
| 253 | regcache_raw_write_unsigned (regcache, S390_PSWM_REGNUM, psw); |
| 254 | break; |
| 255 | |
| 256 | default: |
| 257 | internal_error (__FILE__, __LINE__, _("invalid regnum")); |
| 258 | } |
| 259 | } |
| 260 | |
| 261 | static void |
| 262 | s390x_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache, |
| 263 | int regnum, void *buf) |
| 264 | { |
| 265 | ULONGEST val; |
| 266 | |
| 267 | switch (regnum) |
| 268 | { |
| 269 | case S390_PC_REGNUM: |
| 270 | regcache_raw_read (regcache, S390_PSWA_REGNUM, buf); |
| 271 | break; |
| 272 | |
| 273 | case S390_CC_REGNUM: |
| 274 | regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &val); |
| 275 | store_unsigned_integer (buf, 4, (val >> 44) & 3); |
| 276 | break; |
| 277 | |
| 278 | default: |
| 279 | internal_error (__FILE__, __LINE__, _("invalid regnum")); |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | static void |
| 284 | s390x_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache, |
| 285 | int regnum, const void *buf) |
| 286 | { |
| 287 | ULONGEST val, psw; |
| 288 | |
| 289 | switch (regnum) |
| 290 | { |
| 291 | case S390_PC_REGNUM: |
| 292 | regcache_raw_write (regcache, S390_PSWA_REGNUM, buf); |
| 293 | break; |
| 294 | |
| 295 | case S390_CC_REGNUM: |
| 296 | val = extract_unsigned_integer (buf, 4); |
| 297 | regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &psw); |
| 298 | psw = (psw & ~((ULONGEST)3 << 44)) | ((val & 3) << 44); |
| 299 | regcache_raw_write_unsigned (regcache, S390_PSWM_REGNUM, psw); |
| 300 | break; |
| 301 | |
| 302 | default: |
| 303 | internal_error (__FILE__, __LINE__, _("invalid regnum")); |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | /* 'float' values are stored in the upper half of floating-point |
| 308 | registers, even though we are otherwise a big-endian platform. */ |
| 309 | |
| 310 | static int |
| 311 | s390_convert_register_p (int regno, struct type *type) |
| 312 | { |
| 313 | return (regno >= S390_F0_REGNUM && regno <= S390_F15_REGNUM) |
| 314 | && TYPE_LENGTH (type) < 8; |
| 315 | } |
| 316 | |
| 317 | static void |
| 318 | s390_register_to_value (struct frame_info *frame, int regnum, |
| 319 | struct type *valtype, void *out) |
| 320 | { |
| 321 | char in[8]; |
| 322 | int len = TYPE_LENGTH (valtype); |
| 323 | gdb_assert (len < 8); |
| 324 | |
| 325 | get_frame_register (frame, regnum, in); |
| 326 | memcpy (out, in, len); |
| 327 | } |
| 328 | |
| 329 | static void |
| 330 | s390_value_to_register (struct frame_info *frame, int regnum, |
| 331 | struct type *valtype, const void *in) |
| 332 | { |
| 333 | char out[8]; |
| 334 | int len = TYPE_LENGTH (valtype); |
| 335 | gdb_assert (len < 8); |
| 336 | |
| 337 | memset (out, 0, 8); |
| 338 | memcpy (out, in, len); |
| 339 | put_frame_register (frame, regnum, out); |
| 340 | } |
| 341 | |
| 342 | /* Register groups. */ |
| 343 | |
| 344 | static int |
| 345 | s390_register_reggroup_p (struct gdbarch *gdbarch, int regnum, |
| 346 | struct reggroup *group) |
| 347 | { |
| 348 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 349 | |
| 350 | /* Registers displayed via 'info regs'. */ |
| 351 | if (group == general_reggroup) |
| 352 | return (regnum >= S390_R0_REGNUM && regnum <= S390_R15_REGNUM) |
| 353 | || regnum == S390_PC_REGNUM |
| 354 | || regnum == S390_CC_REGNUM; |
| 355 | |
| 356 | /* Registers displayed via 'info float'. */ |
| 357 | if (group == float_reggroup) |
| 358 | return (regnum >= S390_F0_REGNUM && regnum <= S390_F15_REGNUM) |
| 359 | || regnum == S390_FPC_REGNUM; |
| 360 | |
| 361 | /* Registers that need to be saved/restored in order to |
| 362 | push or pop frames. */ |
| 363 | if (group == save_reggroup || group == restore_reggroup) |
| 364 | return regnum != S390_PSWM_REGNUM && regnum != S390_PSWA_REGNUM; |
| 365 | |
| 366 | return default_register_reggroup_p (gdbarch, regnum, group); |
| 367 | } |
| 368 | |
| 369 | |
| 370 | /* Core file register sets. */ |
| 371 | |
| 372 | int s390_regmap_gregset[S390_NUM_REGS] = |
| 373 | { |
| 374 | /* Program Status Word. */ |
| 375 | 0x00, 0x04, |
| 376 | /* General Purpose Registers. */ |
| 377 | 0x08, 0x0c, 0x10, 0x14, |
| 378 | 0x18, 0x1c, 0x20, 0x24, |
| 379 | 0x28, 0x2c, 0x30, 0x34, |
| 380 | 0x38, 0x3c, 0x40, 0x44, |
| 381 | /* Access Registers. */ |
| 382 | 0x48, 0x4c, 0x50, 0x54, |
| 383 | 0x58, 0x5c, 0x60, 0x64, |
| 384 | 0x68, 0x6c, 0x70, 0x74, |
| 385 | 0x78, 0x7c, 0x80, 0x84, |
| 386 | /* Floating Point Control Word. */ |
| 387 | -1, |
| 388 | /* Floating Point Registers. */ |
| 389 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 390 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 391 | }; |
| 392 | |
| 393 | int s390x_regmap_gregset[S390_NUM_REGS] = |
| 394 | { |
| 395 | 0x00, 0x08, |
| 396 | /* General Purpose Registers. */ |
| 397 | 0x10, 0x18, 0x20, 0x28, |
| 398 | 0x30, 0x38, 0x40, 0x48, |
| 399 | 0x50, 0x58, 0x60, 0x68, |
| 400 | 0x70, 0x78, 0x80, 0x88, |
| 401 | /* Access Registers. */ |
| 402 | 0x90, 0x94, 0x98, 0x9c, |
| 403 | 0xa0, 0xa4, 0xa8, 0xac, |
| 404 | 0xb0, 0xb4, 0xb8, 0xbc, |
| 405 | 0xc0, 0xc4, 0xc8, 0xcc, |
| 406 | /* Floating Point Control Word. */ |
| 407 | -1, |
| 408 | /* Floating Point Registers. */ |
| 409 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 410 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 411 | }; |
| 412 | |
| 413 | int s390_regmap_fpregset[S390_NUM_REGS] = |
| 414 | { |
| 415 | /* Program Status Word. */ |
| 416 | -1, -1, |
| 417 | /* General Purpose Registers. */ |
| 418 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 419 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 420 | /* Access Registers. */ |
| 421 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 422 | -1, -1, -1, -1, -1, -1, -1, -1, |
| 423 | /* Floating Point Control Word. */ |
| 424 | 0x00, |
| 425 | /* Floating Point Registers. */ |
| 426 | 0x08, 0x10, 0x18, 0x20, |
| 427 | 0x28, 0x30, 0x38, 0x40, |
| 428 | 0x48, 0x50, 0x58, 0x60, |
| 429 | 0x68, 0x70, 0x78, 0x80, |
| 430 | }; |
| 431 | |
| 432 | /* Supply register REGNUM from the register set REGSET to register cache |
| 433 | REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ |
| 434 | static void |
| 435 | s390_supply_regset (const struct regset *regset, struct regcache *regcache, |
| 436 | int regnum, const void *regs, size_t len) |
| 437 | { |
| 438 | const int *offset = regset->descr; |
| 439 | int i; |
| 440 | |
| 441 | for (i = 0; i < S390_NUM_REGS; i++) |
| 442 | { |
| 443 | if ((regnum == i || regnum == -1) && offset[i] != -1) |
| 444 | regcache_raw_supply (regcache, i, (const char *)regs + offset[i]); |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | static const struct regset s390_gregset = { |
| 449 | s390_regmap_gregset, |
| 450 | s390_supply_regset |
| 451 | }; |
| 452 | |
| 453 | static const struct regset s390x_gregset = { |
| 454 | s390x_regmap_gregset, |
| 455 | s390_supply_regset |
| 456 | }; |
| 457 | |
| 458 | static const struct regset s390_fpregset = { |
| 459 | s390_regmap_fpregset, |
| 460 | s390_supply_regset |
| 461 | }; |
| 462 | |
| 463 | /* Return the appropriate register set for the core section identified |
| 464 | by SECT_NAME and SECT_SIZE. */ |
| 465 | const struct regset * |
| 466 | s390_regset_from_core_section (struct gdbarch *gdbarch, |
| 467 | const char *sect_name, size_t sect_size) |
| 468 | { |
| 469 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 470 | |
| 471 | if (strcmp (sect_name, ".reg") == 0 && sect_size == tdep->sizeof_gregset) |
| 472 | return tdep->gregset; |
| 473 | |
| 474 | if (strcmp (sect_name, ".reg2") == 0 && sect_size == tdep->sizeof_fpregset) |
| 475 | return tdep->fpregset; |
| 476 | |
| 477 | return NULL; |
| 478 | } |
| 479 | |
| 480 | |
| 481 | /* Prologue analysis. */ |
| 482 | |
| 483 | /* When we analyze a prologue, we're really doing 'abstract |
| 484 | interpretation' or 'pseudo-evaluation': running the function's code |
| 485 | in simulation, but using conservative approximations of the values |
| 486 | it would have when it actually runs. For example, if our function |
| 487 | starts with the instruction: |
| 488 | |
| 489 | ahi r1, 42 # add halfword immediate 42 to r1 |
| 490 | |
| 491 | we don't know exactly what value will be in r1 after executing this |
| 492 | instruction, but we do know it'll be 42 greater than its original |
| 493 | value. |
| 494 | |
| 495 | If we then see an instruction like: |
| 496 | |
| 497 | ahi r1, 22 # add halfword immediate 22 to r1 |
| 498 | |
| 499 | we still don't know what r1's value is, but again, we can say it is |
| 500 | now 64 greater than its original value. |
| 501 | |
| 502 | If the next instruction were: |
| 503 | |
| 504 | lr r2, r1 # set r2 to r1's value |
| 505 | |
| 506 | then we can say that r2's value is now the original value of r1 |
| 507 | plus 64. And so on. |
| 508 | |
| 509 | Of course, this can only go so far before it gets unreasonable. If |
| 510 | we wanted to be able to say anything about the value of r1 after |
| 511 | the instruction: |
| 512 | |
| 513 | xr r1, r3 # exclusive-or r1 and r3, place result in r1 |
| 514 | |
| 515 | then things would get pretty complex. But remember, we're just |
| 516 | doing a conservative approximation; if exclusive-or instructions |
| 517 | aren't relevant to prologues, we can just say r1's value is now |
| 518 | 'unknown'. We can ignore things that are too complex, if that loss |
| 519 | of information is acceptable for our application. |
| 520 | |
| 521 | Once you've reached an instruction that you don't know how to |
| 522 | simulate, you stop. Now you examine the state of the registers and |
| 523 | stack slots you've kept track of. For example: |
| 524 | |
| 525 | - To see how large your stack frame is, just check the value of sp; |
| 526 | if it's the original value of sp minus a constant, then that |
| 527 | constant is the stack frame's size. If the sp's value has been |
| 528 | marked as 'unknown', then that means the prologue has done |
| 529 | something too complex for us to track, and we don't know the |
| 530 | frame size. |
| 531 | |
| 532 | - To see whether we've saved the SP in the current frame's back |
| 533 | chain slot, we just check whether the current value of the back |
| 534 | chain stack slot is the original value of the sp. |
| 535 | |
| 536 | Sure, this takes some work. But prologue analyzers aren't |
| 537 | quick-and-simple pattern patching to recognize a few fixed prologue |
| 538 | forms any more; they're big, hairy functions. Along with inferior |
| 539 | function calls, prologue analysis accounts for a substantial |
| 540 | portion of the time needed to stabilize a GDB port. So I think |
| 541 | it's worthwhile to look for an approach that will be easier to |
| 542 | understand and maintain. In the approach used here: |
| 543 | |
| 544 | - It's easier to see that the analyzer is correct: you just see |
| 545 | whether the analyzer properly (albiet conservatively) simulates |
| 546 | the effect of each instruction. |
| 547 | |
| 548 | - It's easier to extend the analyzer: you can add support for new |
| 549 | instructions, and know that you haven't broken anything that |
| 550 | wasn't already broken before. |
| 551 | |
| 552 | - It's orthogonal: to gather new information, you don't need to |
| 553 | complicate the code for each instruction. As long as your domain |
| 554 | of conservative values is already detailed enough to tell you |
| 555 | what you need, then all the existing instruction simulations are |
| 556 | already gathering the right data for you. |
| 557 | |
| 558 | A 'struct prologue_value' is a conservative approximation of the |
| 559 | real value the register or stack slot will have. */ |
| 560 | |
| 561 | struct prologue_value { |
| 562 | |
| 563 | /* What sort of value is this? This determines the interpretation |
| 564 | of subsequent fields. */ |
| 565 | enum { |
| 566 | |
| 567 | /* We don't know anything about the value. This is also used for |
| 568 | values we could have kept track of, when doing so would have |
| 569 | been too complex and we don't want to bother. The bottom of |
| 570 | our lattice. */ |
| 571 | pv_unknown, |
| 572 | |
| 573 | /* A known constant. K is its value. */ |
| 574 | pv_constant, |
| 575 | |
| 576 | /* The value that register REG originally had *UPON ENTRY TO THE |
| 577 | FUNCTION*, plus K. If K is zero, this means, obviously, just |
| 578 | the value REG had upon entry to the function. REG is a GDB |
| 579 | register number. Before we start interpreting, we initialize |
| 580 | every register R to { pv_register, R, 0 }. */ |
| 581 | pv_register, |
| 582 | |
| 583 | } kind; |
| 584 | |
| 585 | /* The meanings of the following fields depend on 'kind'; see the |
| 586 | comments for the specific 'kind' values. */ |
| 587 | int reg; |
| 588 | CORE_ADDR k; |
| 589 | }; |
| 590 | |
| 591 | |
| 592 | /* Set V to be unknown. */ |
| 593 | static void |
| 594 | pv_set_to_unknown (struct prologue_value *v) |
| 595 | { |
| 596 | v->kind = pv_unknown; |
| 597 | } |
| 598 | |
| 599 | |
| 600 | /* Set V to the constant K. */ |
| 601 | static void |
| 602 | pv_set_to_constant (struct prologue_value *v, CORE_ADDR k) |
| 603 | { |
| 604 | v->kind = pv_constant; |
| 605 | v->k = k; |
| 606 | } |
| 607 | |
| 608 | |
| 609 | /* Set V to the original value of register REG, plus K. */ |
| 610 | static void |
| 611 | pv_set_to_register (struct prologue_value *v, int reg, CORE_ADDR k) |
| 612 | { |
| 613 | v->kind = pv_register; |
| 614 | v->reg = reg; |
| 615 | v->k = k; |
| 616 | } |
| 617 | |
| 618 | |
| 619 | /* If one of *A and *B is a constant, and the other isn't, swap the |
| 620 | pointers as necessary to ensure that *B points to the constant. |
| 621 | This can reduce the number of cases we need to analyze in the |
| 622 | functions below. */ |
| 623 | static void |
| 624 | pv_constant_last (struct prologue_value **a, |
| 625 | struct prologue_value **b) |
| 626 | { |
| 627 | if ((*a)->kind == pv_constant |
| 628 | && (*b)->kind != pv_constant) |
| 629 | { |
| 630 | struct prologue_value *temp = *a; |
| 631 | *a = *b; |
| 632 | *b = temp; |
| 633 | } |
| 634 | } |
| 635 | |
| 636 | |
| 637 | /* Set SUM to the sum of A and B. SUM, A, and B may point to the same |
| 638 | 'struct prologue_value' object. */ |
| 639 | static void |
| 640 | pv_add (struct prologue_value *sum, |
| 641 | struct prologue_value *a, |
| 642 | struct prologue_value *b) |
| 643 | { |
| 644 | pv_constant_last (&a, &b); |
| 645 | |
| 646 | /* We can handle adding constants to registers, and other constants. */ |
| 647 | if (b->kind == pv_constant |
| 648 | && (a->kind == pv_register |
| 649 | || a->kind == pv_constant)) |
| 650 | { |
| 651 | sum->kind = a->kind; |
| 652 | sum->reg = a->reg; /* not meaningful if a is pv_constant, but |
| 653 | harmless */ |
| 654 | sum->k = a->k + b->k; |
| 655 | } |
| 656 | |
| 657 | /* Anything else we don't know how to add. We don't have a |
| 658 | representation for, say, the sum of two registers, or a multiple |
| 659 | of a register's value (adding a register to itself). */ |
| 660 | else |
| 661 | sum->kind = pv_unknown; |
| 662 | } |
| 663 | |
| 664 | |
| 665 | /* Add the constant K to V. */ |
| 666 | static void |
| 667 | pv_add_constant (struct prologue_value *v, CORE_ADDR k) |
| 668 | { |
| 669 | struct prologue_value pv_k; |
| 670 | |
| 671 | /* Rather than thinking of all the cases we can and can't handle, |
| 672 | we'll just let pv_add take care of that for us. */ |
| 673 | pv_set_to_constant (&pv_k, k); |
| 674 | pv_add (v, v, &pv_k); |
| 675 | } |
| 676 | |
| 677 | |
| 678 | /* Subtract B from A, and put the result in DIFF. |
| 679 | |
| 680 | This isn't quite the same as negating B and adding it to A, since |
| 681 | we don't have a representation for the negation of anything but a |
| 682 | constant. For example, we can't negate { pv_register, R1, 10 }, |
| 683 | but we do know that { pv_register, R1, 10 } minus { pv_register, |
| 684 | R1, 5 } is { pv_constant, <ignored>, 5 }. |
| 685 | |
| 686 | This means, for example, that we can subtract two stack addresses; |
| 687 | they're both relative to the original SP. Since the frame pointer |
| 688 | is set based on the SP, its value will be the original SP plus some |
| 689 | constant (probably zero), so we can use its value just fine. */ |
| 690 | static void |
| 691 | pv_subtract (struct prologue_value *diff, |
| 692 | struct prologue_value *a, |
| 693 | struct prologue_value *b) |
| 694 | { |
| 695 | pv_constant_last (&a, &b); |
| 696 | |
| 697 | /* We can subtract a constant from another constant, or from a |
| 698 | register. */ |
| 699 | if (b->kind == pv_constant |
| 700 | && (a->kind == pv_register |
| 701 | || a->kind == pv_constant)) |
| 702 | { |
| 703 | diff->kind = a->kind; |
| 704 | diff->reg = a->reg; /* not always meaningful, but harmless */ |
| 705 | diff->k = a->k - b->k; |
| 706 | } |
| 707 | |
| 708 | /* We can subtract a register from itself, yielding a constant. */ |
| 709 | else if (a->kind == pv_register |
| 710 | && b->kind == pv_register |
| 711 | && a->reg == b->reg) |
| 712 | { |
| 713 | diff->kind = pv_constant; |
| 714 | diff->k = a->k - b->k; |
| 715 | } |
| 716 | |
| 717 | /* We don't know how to subtract anything else. */ |
| 718 | else |
| 719 | diff->kind = pv_unknown; |
| 720 | } |
| 721 | |
| 722 | |
| 723 | /* Set AND to the logical and of A and B. */ |
| 724 | static void |
| 725 | pv_logical_and (struct prologue_value *and, |
| 726 | struct prologue_value *a, |
| 727 | struct prologue_value *b) |
| 728 | { |
| 729 | pv_constant_last (&a, &b); |
| 730 | |
| 731 | /* We can 'and' two constants. */ |
| 732 | if (a->kind == pv_constant |
| 733 | && b->kind == pv_constant) |
| 734 | { |
| 735 | and->kind = pv_constant; |
| 736 | and->k = a->k & b->k; |
| 737 | } |
| 738 | |
| 739 | /* We can 'and' anything with the constant zero. */ |
| 740 | else if (b->kind == pv_constant |
| 741 | && b->k == 0) |
| 742 | { |
| 743 | and->kind = pv_constant; |
| 744 | and->k = 0; |
| 745 | } |
| 746 | |
| 747 | /* We can 'and' anything with ~0. */ |
| 748 | else if (b->kind == pv_constant |
| 749 | && b->k == ~ (CORE_ADDR) 0) |
| 750 | *and = *a; |
| 751 | |
| 752 | /* We can 'and' a register with itself. */ |
| 753 | else if (a->kind == pv_register |
| 754 | && b->kind == pv_register |
| 755 | && a->reg == b->reg |
| 756 | && a->k == b->k) |
| 757 | *and = *a; |
| 758 | |
| 759 | /* Otherwise, we don't know. */ |
| 760 | else |
| 761 | pv_set_to_unknown (and); |
| 762 | } |
| 763 | |
| 764 | |
| 765 | /* Return non-zero iff A and B are identical expressions. |
| 766 | |
| 767 | This is not the same as asking if the two values are equal; the |
| 768 | result of such a comparison would have to be a pv_boolean, and |
| 769 | asking whether two 'unknown' values were equal would give you |
| 770 | pv_maybe. Same for comparing, say, { pv_register, R1, 0 } and { |
| 771 | pv_register, R2, 0}. Instead, this is asking whether the two |
| 772 | representations are the same. */ |
| 773 | static int |
| 774 | pv_is_identical (struct prologue_value *a, |
| 775 | struct prologue_value *b) |
| 776 | { |
| 777 | if (a->kind != b->kind) |
| 778 | return 0; |
| 779 | |
| 780 | switch (a->kind) |
| 781 | { |
| 782 | case pv_unknown: |
| 783 | return 1; |
| 784 | case pv_constant: |
| 785 | return (a->k == b->k); |
| 786 | case pv_register: |
| 787 | return (a->reg == b->reg && a->k == b->k); |
| 788 | default: |
| 789 | gdb_assert (0); |
| 790 | } |
| 791 | } |
| 792 | |
| 793 | |
| 794 | /* Return non-zero if A is the original value of register number R |
| 795 | plus K, zero otherwise. */ |
| 796 | static int |
| 797 | pv_is_register (struct prologue_value *a, int r, CORE_ADDR k) |
| 798 | { |
| 799 | return (a->kind == pv_register |
| 800 | && a->reg == r |
| 801 | && a->k == k); |
| 802 | } |
| 803 | |
| 804 | |
| 805 | /* Decoding S/390 instructions. */ |
| 806 | |
| 807 | /* Named opcode values for the S/390 instructions we recognize. Some |
| 808 | instructions have their opcode split across two fields; those are the |
| 809 | op1_* and op2_* enums. */ |
| 810 | enum |
| 811 | { |
| 812 | op1_lhi = 0xa7, op2_lhi = 0x08, |
| 813 | op1_lghi = 0xa7, op2_lghi = 0x09, |
| 814 | op_lr = 0x18, |
| 815 | op_lgr = 0xb904, |
| 816 | op_l = 0x58, |
| 817 | op1_ly = 0xe3, op2_ly = 0x58, |
| 818 | op1_lg = 0xe3, op2_lg = 0x04, |
| 819 | op_lm = 0x98, |
| 820 | op1_lmy = 0xeb, op2_lmy = 0x98, |
| 821 | op1_lmg = 0xeb, op2_lmg = 0x04, |
| 822 | op_st = 0x50, |
| 823 | op1_sty = 0xe3, op2_sty = 0x50, |
| 824 | op1_stg = 0xe3, op2_stg = 0x24, |
| 825 | op_std = 0x60, |
| 826 | op_stm = 0x90, |
| 827 | op1_stmy = 0xeb, op2_stmy = 0x90, |
| 828 | op1_stmg = 0xeb, op2_stmg = 0x24, |
| 829 | op1_aghi = 0xa7, op2_aghi = 0x0b, |
| 830 | op1_ahi = 0xa7, op2_ahi = 0x0a, |
| 831 | op_ar = 0x1a, |
| 832 | op_agr = 0xb908, |
| 833 | op_a = 0x5a, |
| 834 | op1_ay = 0xe3, op2_ay = 0x5a, |
| 835 | op1_ag = 0xe3, op2_ag = 0x08, |
| 836 | op_sr = 0x1b, |
| 837 | op_sgr = 0xb909, |
| 838 | op_s = 0x5b, |
| 839 | op1_sy = 0xe3, op2_sy = 0x5b, |
| 840 | op1_sg = 0xe3, op2_sg = 0x09, |
| 841 | op_nr = 0x14, |
| 842 | op_ngr = 0xb980, |
| 843 | op_la = 0x41, |
| 844 | op1_lay = 0xe3, op2_lay = 0x71, |
| 845 | op1_larl = 0xc0, op2_larl = 0x00, |
| 846 | op_basr = 0x0d, |
| 847 | op_bas = 0x4d, |
| 848 | op_bcr = 0x07, |
| 849 | op_bc = 0x0d, |
| 850 | op1_bras = 0xa7, op2_bras = 0x05, |
| 851 | op1_brasl= 0xc0, op2_brasl= 0x05, |
| 852 | op1_brc = 0xa7, op2_brc = 0x04, |
| 853 | op1_brcl = 0xc0, op2_brcl = 0x04, |
| 854 | }; |
| 855 | |
| 856 | |
| 857 | /* Read a single instruction from address AT. */ |
| 858 | |
| 859 | #define S390_MAX_INSTR_SIZE 6 |
| 860 | static int |
| 861 | s390_readinstruction (bfd_byte instr[], CORE_ADDR at) |
| 862 | { |
| 863 | static int s390_instrlen[] = { 2, 4, 4, 6 }; |
| 864 | int instrlen; |
| 865 | |
| 866 | if (deprecated_read_memory_nobpt (at, &instr[0], 2)) |
| 867 | return -1; |
| 868 | instrlen = s390_instrlen[instr[0] >> 6]; |
| 869 | if (instrlen > 2) |
| 870 | { |
| 871 | if (deprecated_read_memory_nobpt (at + 2, &instr[2], instrlen - 2)) |
| 872 | return -1; |
| 873 | } |
| 874 | return instrlen; |
| 875 | } |
| 876 | |
| 877 | |
| 878 | /* The functions below are for recognizing and decoding S/390 |
| 879 | instructions of various formats. Each of them checks whether INSN |
| 880 | is an instruction of the given format, with the specified opcodes. |
| 881 | If it is, it sets the remaining arguments to the values of the |
| 882 | instruction's fields, and returns a non-zero value; otherwise, it |
| 883 | returns zero. |
| 884 | |
| 885 | These functions' arguments appear in the order they appear in the |
| 886 | instruction, not in the machine-language form. So, opcodes always |
| 887 | come first, even though they're sometimes scattered around the |
| 888 | instructions. And displacements appear before base and extension |
| 889 | registers, as they do in the assembly syntax, not at the end, as |
| 890 | they do in the machine language. */ |
| 891 | static int |
| 892 | is_ri (bfd_byte *insn, int op1, int op2, unsigned int *r1, int *i2) |
| 893 | { |
| 894 | if (insn[0] == op1 && (insn[1] & 0xf) == op2) |
| 895 | { |
| 896 | *r1 = (insn[1] >> 4) & 0xf; |
| 897 | /* i2 is a 16-bit signed quantity. */ |
| 898 | *i2 = (((insn[2] << 8) | insn[3]) ^ 0x8000) - 0x8000; |
| 899 | return 1; |
| 900 | } |
| 901 | else |
| 902 | return 0; |
| 903 | } |
| 904 | |
| 905 | |
| 906 | static int |
| 907 | is_ril (bfd_byte *insn, int op1, int op2, |
| 908 | unsigned int *r1, int *i2) |
| 909 | { |
| 910 | if (insn[0] == op1 && (insn[1] & 0xf) == op2) |
| 911 | { |
| 912 | *r1 = (insn[1] >> 4) & 0xf; |
| 913 | /* i2 is a signed quantity. If the host 'int' is 32 bits long, |
| 914 | no sign extension is necessary, but we don't want to assume |
| 915 | that. */ |
| 916 | *i2 = (((insn[2] << 24) |
| 917 | | (insn[3] << 16) |
| 918 | | (insn[4] << 8) |
| 919 | | (insn[5])) ^ 0x80000000) - 0x80000000; |
| 920 | return 1; |
| 921 | } |
| 922 | else |
| 923 | return 0; |
| 924 | } |
| 925 | |
| 926 | |
| 927 | static int |
| 928 | is_rr (bfd_byte *insn, int op, unsigned int *r1, unsigned int *r2) |
| 929 | { |
| 930 | if (insn[0] == op) |
| 931 | { |
| 932 | *r1 = (insn[1] >> 4) & 0xf; |
| 933 | *r2 = insn[1] & 0xf; |
| 934 | return 1; |
| 935 | } |
| 936 | else |
| 937 | return 0; |
| 938 | } |
| 939 | |
| 940 | |
| 941 | static int |
| 942 | is_rre (bfd_byte *insn, int op, unsigned int *r1, unsigned int *r2) |
| 943 | { |
| 944 | if (((insn[0] << 8) | insn[1]) == op) |
| 945 | { |
| 946 | /* Yes, insn[3]. insn[2] is unused in RRE format. */ |
| 947 | *r1 = (insn[3] >> 4) & 0xf; |
| 948 | *r2 = insn[3] & 0xf; |
| 949 | return 1; |
| 950 | } |
| 951 | else |
| 952 | return 0; |
| 953 | } |
| 954 | |
| 955 | |
| 956 | static int |
| 957 | is_rs (bfd_byte *insn, int op, |
| 958 | unsigned int *r1, unsigned int *r3, unsigned int *d2, unsigned int *b2) |
| 959 | { |
| 960 | if (insn[0] == op) |
| 961 | { |
| 962 | *r1 = (insn[1] >> 4) & 0xf; |
| 963 | *r3 = insn[1] & 0xf; |
| 964 | *b2 = (insn[2] >> 4) & 0xf; |
| 965 | *d2 = ((insn[2] & 0xf) << 8) | insn[3]; |
| 966 | return 1; |
| 967 | } |
| 968 | else |
| 969 | return 0; |
| 970 | } |
| 971 | |
| 972 | |
| 973 | static int |
| 974 | is_rsy (bfd_byte *insn, int op1, int op2, |
| 975 | unsigned int *r1, unsigned int *r3, unsigned int *d2, unsigned int *b2) |
| 976 | { |
| 977 | if (insn[0] == op1 |
| 978 | && insn[5] == op2) |
| 979 | { |
| 980 | *r1 = (insn[1] >> 4) & 0xf; |
| 981 | *r3 = insn[1] & 0xf; |
| 982 | *b2 = (insn[2] >> 4) & 0xf; |
| 983 | /* The 'long displacement' is a 20-bit signed integer. */ |
| 984 | *d2 = ((((insn[2] & 0xf) << 8) | insn[3] | (insn[4] << 12)) |
| 985 | ^ 0x80000) - 0x80000; |
| 986 | return 1; |
| 987 | } |
| 988 | else |
| 989 | return 0; |
| 990 | } |
| 991 | |
| 992 | |
| 993 | static int |
| 994 | is_rx (bfd_byte *insn, int op, |
| 995 | unsigned int *r1, unsigned int *d2, unsigned int *x2, unsigned int *b2) |
| 996 | { |
| 997 | if (insn[0] == op) |
| 998 | { |
| 999 | *r1 = (insn[1] >> 4) & 0xf; |
| 1000 | *x2 = insn[1] & 0xf; |
| 1001 | *b2 = (insn[2] >> 4) & 0xf; |
| 1002 | *d2 = ((insn[2] & 0xf) << 8) | insn[3]; |
| 1003 | return 1; |
| 1004 | } |
| 1005 | else |
| 1006 | return 0; |
| 1007 | } |
| 1008 | |
| 1009 | |
| 1010 | static int |
| 1011 | is_rxy (bfd_byte *insn, int op1, int op2, |
| 1012 | unsigned int *r1, unsigned int *d2, unsigned int *x2, unsigned int *b2) |
| 1013 | { |
| 1014 | if (insn[0] == op1 |
| 1015 | && insn[5] == op2) |
| 1016 | { |
| 1017 | *r1 = (insn[1] >> 4) & 0xf; |
| 1018 | *x2 = insn[1] & 0xf; |
| 1019 | *b2 = (insn[2] >> 4) & 0xf; |
| 1020 | /* The 'long displacement' is a 20-bit signed integer. */ |
| 1021 | *d2 = ((((insn[2] & 0xf) << 8) | insn[3] | (insn[4] << 12)) |
| 1022 | ^ 0x80000) - 0x80000; |
| 1023 | return 1; |
| 1024 | } |
| 1025 | else |
| 1026 | return 0; |
| 1027 | } |
| 1028 | |
| 1029 | |
| 1030 | /* Set ADDR to the effective address for an X-style instruction, like: |
| 1031 | |
| 1032 | L R1, D2(X2, B2) |
| 1033 | |
| 1034 | Here, X2 and B2 are registers, and D2 is a signed 20-bit |
| 1035 | constant; the effective address is the sum of all three. If either |
| 1036 | X2 or B2 are zero, then it doesn't contribute to the sum --- this |
| 1037 | means that r0 can't be used as either X2 or B2. |
| 1038 | |
| 1039 | GPR is an array of general register values, indexed by GPR number, |
| 1040 | not GDB register number. */ |
| 1041 | static void |
| 1042 | compute_x_addr (struct prologue_value *addr, |
| 1043 | struct prologue_value *gpr, |
| 1044 | int d2, unsigned int x2, unsigned int b2) |
| 1045 | { |
| 1046 | /* We can't just add stuff directly in addr; it might alias some of |
| 1047 | the registers we need to read. */ |
| 1048 | struct prologue_value result; |
| 1049 | |
| 1050 | pv_set_to_constant (&result, d2); |
| 1051 | if (x2) |
| 1052 | pv_add (&result, &result, &gpr[x2]); |
| 1053 | if (b2) |
| 1054 | pv_add (&result, &result, &gpr[b2]); |
| 1055 | |
| 1056 | *addr = result; |
| 1057 | } |
| 1058 | |
| 1059 | |
| 1060 | #define S390_NUM_GPRS 16 |
| 1061 | #define S390_NUM_FPRS 16 |
| 1062 | |
| 1063 | struct s390_prologue_data { |
| 1064 | |
| 1065 | /* The size of a GPR or FPR. */ |
| 1066 | int gpr_size; |
| 1067 | int fpr_size; |
| 1068 | |
| 1069 | /* The general-purpose registers. */ |
| 1070 | struct prologue_value gpr[S390_NUM_GPRS]; |
| 1071 | |
| 1072 | /* The floating-point registers. */ |
| 1073 | struct prologue_value fpr[S390_NUM_FPRS]; |
| 1074 | |
| 1075 | /* The offset relative to the CFA where the incoming GPR N was saved |
| 1076 | by the function prologue. 0 if not saved or unknown. */ |
| 1077 | int gpr_slot[S390_NUM_GPRS]; |
| 1078 | |
| 1079 | /* Likewise for FPRs. */ |
| 1080 | int fpr_slot[S390_NUM_FPRS]; |
| 1081 | |
| 1082 | /* Nonzero if the backchain was saved. This is assumed to be the |
| 1083 | case when the incoming SP is saved at the current SP location. */ |
| 1084 | int back_chain_saved_p; |
| 1085 | }; |
| 1086 | |
| 1087 | /* Do a SIZE-byte store of VALUE to ADDR. */ |
| 1088 | static void |
| 1089 | s390_store (struct prologue_value *addr, |
| 1090 | CORE_ADDR size, |
| 1091 | struct prologue_value *value, |
| 1092 | struct s390_prologue_data *data) |
| 1093 | { |
| 1094 | struct prologue_value cfa, offset; |
| 1095 | int i; |
| 1096 | |
| 1097 | /* Check whether we are storing the backchain. */ |
| 1098 | pv_subtract (&offset, &data->gpr[S390_SP_REGNUM - S390_R0_REGNUM], addr); |
| 1099 | |
| 1100 | if (offset.kind == pv_constant && offset.k == 0) |
| 1101 | if (size == data->gpr_size |
| 1102 | && pv_is_register (value, S390_SP_REGNUM, 0)) |
| 1103 | { |
| 1104 | data->back_chain_saved_p = 1; |
| 1105 | return; |
| 1106 | } |
| 1107 | |
| 1108 | |
| 1109 | /* Check whether we are storing a register into the stack. */ |
| 1110 | pv_set_to_register (&cfa, S390_SP_REGNUM, 16 * data->gpr_size + 32); |
| 1111 | pv_subtract (&offset, &cfa, addr); |
| 1112 | |
| 1113 | if (offset.kind == pv_constant |
| 1114 | && offset.k < INT_MAX && offset.k > 0 |
| 1115 | && offset.k % data->gpr_size == 0) |
| 1116 | { |
| 1117 | /* If we are storing the original value of a register, we want to |
| 1118 | record the CFA offset. If the same register is stored multiple |
| 1119 | times, the stack slot with the highest address counts. */ |
| 1120 | |
| 1121 | for (i = 0; i < S390_NUM_GPRS; i++) |
| 1122 | if (size == data->gpr_size |
| 1123 | && pv_is_register (value, S390_R0_REGNUM + i, 0)) |
| 1124 | if (data->gpr_slot[i] == 0 |
| 1125 | || data->gpr_slot[i] > offset.k) |
| 1126 | { |
| 1127 | data->gpr_slot[i] = offset.k; |
| 1128 | return; |
| 1129 | } |
| 1130 | |
| 1131 | for (i = 0; i < S390_NUM_FPRS; i++) |
| 1132 | if (size == data->fpr_size |
| 1133 | && pv_is_register (value, S390_F0_REGNUM + i, 0)) |
| 1134 | if (data->fpr_slot[i] == 0 |
| 1135 | || data->fpr_slot[i] > offset.k) |
| 1136 | { |
| 1137 | data->fpr_slot[i] = offset.k; |
| 1138 | return; |
| 1139 | } |
| 1140 | } |
| 1141 | |
| 1142 | |
| 1143 | /* Note: If this is some store we cannot identify, you might think we |
| 1144 | should forget our cached values, as any of those might have been hit. |
| 1145 | |
| 1146 | However, we make the assumption that the register save areas are only |
| 1147 | ever stored to once in any given function, and we do recognize these |
| 1148 | stores. Thus every store we cannot recognize does not hit our data. */ |
| 1149 | } |
| 1150 | |
| 1151 | /* Do a SIZE-byte load from ADDR into VALUE. */ |
| 1152 | static void |
| 1153 | s390_load (struct prologue_value *addr, |
| 1154 | CORE_ADDR size, |
| 1155 | struct prologue_value *value, |
| 1156 | struct s390_prologue_data *data) |
| 1157 | { |
| 1158 | struct prologue_value cfa, offset; |
| 1159 | int i; |
| 1160 | |
| 1161 | /* If it's a load from an in-line constant pool, then we can |
| 1162 | simulate that, under the assumption that the code isn't |
| 1163 | going to change between the time the processor actually |
| 1164 | executed it creating the current frame, and the time when |
| 1165 | we're analyzing the code to unwind past that frame. */ |
| 1166 | if (addr->kind == pv_constant) |
| 1167 | { |
| 1168 | struct section_table *secp; |
| 1169 | secp = target_section_by_addr (¤t_target, addr->k); |
| 1170 | if (secp != NULL |
| 1171 | && (bfd_get_section_flags (secp->bfd, secp->the_bfd_section) |
| 1172 | & SEC_READONLY)) |
| 1173 | { |
| 1174 | pv_set_to_constant (value, read_memory_integer (addr->k, size)); |
| 1175 | return; |
| 1176 | } |
| 1177 | } |
| 1178 | |
| 1179 | /* Check whether we are accessing one of our save slots. */ |
| 1180 | pv_set_to_register (&cfa, S390_SP_REGNUM, 16 * data->gpr_size + 32); |
| 1181 | pv_subtract (&offset, &cfa, addr); |
| 1182 | |
| 1183 | if (offset.kind == pv_constant |
| 1184 | && offset.k < INT_MAX && offset.k > 0) |
| 1185 | { |
| 1186 | for (i = 0; i < S390_NUM_GPRS; i++) |
| 1187 | if (offset.k == data->gpr_slot[i]) |
| 1188 | { |
| 1189 | pv_set_to_register (value, S390_R0_REGNUM + i, 0); |
| 1190 | return; |
| 1191 | } |
| 1192 | |
| 1193 | for (i = 0; i < S390_NUM_FPRS; i++) |
| 1194 | if (offset.k == data->fpr_slot[i]) |
| 1195 | { |
| 1196 | pv_set_to_register (value, S390_F0_REGNUM + i, 0); |
| 1197 | return; |
| 1198 | } |
| 1199 | } |
| 1200 | |
| 1201 | /* Otherwise, we don't know the value. */ |
| 1202 | pv_set_to_unknown (value); |
| 1203 | } |
| 1204 | |
| 1205 | |
| 1206 | /* Analyze the prologue of the function starting at START_PC, |
| 1207 | continuing at most until CURRENT_PC. Initialize DATA to |
| 1208 | hold all information we find out about the state of the registers |
| 1209 | and stack slots. Return the address of the instruction after |
| 1210 | the last one that changed the SP, FP, or back chain; or zero |
| 1211 | on error. */ |
| 1212 | static CORE_ADDR |
| 1213 | s390_analyze_prologue (struct gdbarch *gdbarch, |
| 1214 | CORE_ADDR start_pc, |
| 1215 | CORE_ADDR current_pc, |
| 1216 | struct s390_prologue_data *data) |
| 1217 | { |
| 1218 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 1219 | |
| 1220 | /* Our return value: |
| 1221 | The address of the instruction after the last one that changed |
| 1222 | the SP, FP, or back chain; zero if we got an error trying to |
| 1223 | read memory. */ |
| 1224 | CORE_ADDR result = start_pc; |
| 1225 | |
| 1226 | /* The current PC for our abstract interpretation. */ |
| 1227 | CORE_ADDR pc; |
| 1228 | |
| 1229 | /* The address of the next instruction after that. */ |
| 1230 | CORE_ADDR next_pc; |
| 1231 | |
| 1232 | /* Set up everything's initial value. */ |
| 1233 | { |
| 1234 | int i; |
| 1235 | |
| 1236 | /* For the purpose of prologue tracking, we consider the GPR size to |
| 1237 | be equal to the ABI word size, even if it is actually larger |
| 1238 | (i.e. when running a 32-bit binary under a 64-bit kernel). */ |
| 1239 | data->gpr_size = word_size; |
| 1240 | data->fpr_size = 8; |
| 1241 | |
| 1242 | for (i = 0; i < S390_NUM_GPRS; i++) |
| 1243 | pv_set_to_register (&data->gpr[i], S390_R0_REGNUM + i, 0); |
| 1244 | |
| 1245 | for (i = 0; i < S390_NUM_FPRS; i++) |
| 1246 | pv_set_to_register (&data->fpr[i], S390_F0_REGNUM + i, 0); |
| 1247 | |
| 1248 | for (i = 0; i < S390_NUM_GPRS; i++) |
| 1249 | data->gpr_slot[i] = 0; |
| 1250 | |
| 1251 | for (i = 0; i < S390_NUM_FPRS; i++) |
| 1252 | data->fpr_slot[i] = 0; |
| 1253 | |
| 1254 | data->back_chain_saved_p = 0; |
| 1255 | } |
| 1256 | |
| 1257 | /* Start interpreting instructions, until we hit the frame's |
| 1258 | current PC or the first branch instruction. */ |
| 1259 | for (pc = start_pc; pc > 0 && pc < current_pc; pc = next_pc) |
| 1260 | { |
| 1261 | bfd_byte insn[S390_MAX_INSTR_SIZE]; |
| 1262 | int insn_len = s390_readinstruction (insn, pc); |
| 1263 | |
| 1264 | /* Fields for various kinds of instructions. */ |
| 1265 | unsigned int b2, r1, r2, x2, r3; |
| 1266 | int i2, d2; |
| 1267 | |
| 1268 | /* The values of SP and FP before this instruction, |
| 1269 | for detecting instructions that change them. */ |
| 1270 | struct prologue_value pre_insn_sp, pre_insn_fp; |
| 1271 | /* Likewise for the flag whether the back chain was saved. */ |
| 1272 | int pre_insn_back_chain_saved_p; |
| 1273 | |
| 1274 | /* If we got an error trying to read the instruction, report it. */ |
| 1275 | if (insn_len < 0) |
| 1276 | { |
| 1277 | result = 0; |
| 1278 | break; |
| 1279 | } |
| 1280 | |
| 1281 | next_pc = pc + insn_len; |
| 1282 | |
| 1283 | pre_insn_sp = data->gpr[S390_SP_REGNUM - S390_R0_REGNUM]; |
| 1284 | pre_insn_fp = data->gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; |
| 1285 | pre_insn_back_chain_saved_p = data->back_chain_saved_p; |
| 1286 | |
| 1287 | /* LHI r1, i2 --- load halfword immediate */ |
| 1288 | if (word_size == 4 |
| 1289 | && is_ri (insn, op1_lhi, op2_lhi, &r1, &i2)) |
| 1290 | pv_set_to_constant (&data->gpr[r1], i2); |
| 1291 | |
| 1292 | /* LGHI r1, i2 --- load halfword immediate (64-bit version) */ |
| 1293 | else if (word_size == 8 |
| 1294 | && is_ri (insn, op1_lghi, op2_lghi, &r1, &i2)) |
| 1295 | pv_set_to_constant (&data->gpr[r1], i2); |
| 1296 | |
| 1297 | /* LR r1, r2 --- load from register */ |
| 1298 | else if (word_size == 4 |
| 1299 | && is_rr (insn, op_lr, &r1, &r2)) |
| 1300 | data->gpr[r1] = data->gpr[r2]; |
| 1301 | |
| 1302 | /* LGR r1, r2 --- load from register (64-bit version) */ |
| 1303 | else if (word_size == 8 |
| 1304 | && is_rre (insn, op_lgr, &r1, &r2)) |
| 1305 | data->gpr[r1] = data->gpr[r2]; |
| 1306 | |
| 1307 | /* L r1, d2(x2, b2) --- load */ |
| 1308 | else if (word_size == 4 |
| 1309 | && is_rx (insn, op_l, &r1, &d2, &x2, &b2)) |
| 1310 | { |
| 1311 | struct prologue_value addr; |
| 1312 | |
| 1313 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1314 | s390_load (&addr, 4, &data->gpr[r1], data); |
| 1315 | } |
| 1316 | |
| 1317 | /* LY r1, d2(x2, b2) --- load (long-displacement version) */ |
| 1318 | else if (word_size == 4 |
| 1319 | && is_rxy (insn, op1_ly, op2_ly, &r1, &d2, &x2, &b2)) |
| 1320 | { |
| 1321 | struct prologue_value addr; |
| 1322 | |
| 1323 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1324 | s390_load (&addr, 4, &data->gpr[r1], data); |
| 1325 | } |
| 1326 | |
| 1327 | /* LG r1, d2(x2, b2) --- load (64-bit version) */ |
| 1328 | else if (word_size == 8 |
| 1329 | && is_rxy (insn, op1_lg, op2_lg, &r1, &d2, &x2, &b2)) |
| 1330 | { |
| 1331 | struct prologue_value addr; |
| 1332 | |
| 1333 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1334 | s390_load (&addr, 8, &data->gpr[r1], data); |
| 1335 | } |
| 1336 | |
| 1337 | /* ST r1, d2(x2, b2) --- store */ |
| 1338 | else if (word_size == 4 |
| 1339 | && is_rx (insn, op_st, &r1, &d2, &x2, &b2)) |
| 1340 | { |
| 1341 | struct prologue_value addr; |
| 1342 | |
| 1343 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1344 | s390_store (&addr, 4, &data->gpr[r1], data); |
| 1345 | } |
| 1346 | |
| 1347 | /* STY r1, d2(x2, b2) --- store (long-displacement version) */ |
| 1348 | else if (word_size == 4 |
| 1349 | && is_rxy (insn, op1_sty, op2_sty, &r1, &d2, &x2, &b2)) |
| 1350 | { |
| 1351 | struct prologue_value addr; |
| 1352 | |
| 1353 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1354 | s390_store (&addr, 4, &data->gpr[r1], data); |
| 1355 | } |
| 1356 | |
| 1357 | /* STG r1, d2(x2, b2) --- store (64-bit version) */ |
| 1358 | else if (word_size == 8 |
| 1359 | && is_rxy (insn, op1_stg, op2_stg, &r1, &d2, &x2, &b2)) |
| 1360 | { |
| 1361 | struct prologue_value addr; |
| 1362 | |
| 1363 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1364 | s390_store (&addr, 8, &data->gpr[r1], data); |
| 1365 | } |
| 1366 | |
| 1367 | /* STD r1, d2(x2,b2) --- store floating-point register */ |
| 1368 | else if (is_rx (insn, op_std, &r1, &d2, &x2, &b2)) |
| 1369 | { |
| 1370 | struct prologue_value addr; |
| 1371 | |
| 1372 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1373 | s390_store (&addr, 8, &data->fpr[r1], data); |
| 1374 | } |
| 1375 | |
| 1376 | /* STM r1, r3, d2(b2) --- store multiple */ |
| 1377 | else if (word_size == 4 |
| 1378 | && is_rs (insn, op_stm, &r1, &r3, &d2, &b2)) |
| 1379 | { |
| 1380 | int regnum; |
| 1381 | int offset; |
| 1382 | struct prologue_value addr; |
| 1383 | |
| 1384 | for (regnum = r1, offset = 0; |
| 1385 | regnum <= r3; |
| 1386 | regnum++, offset += 4) |
| 1387 | { |
| 1388 | compute_x_addr (&addr, data->gpr, d2 + offset, 0, b2); |
| 1389 | s390_store (&addr, 4, &data->gpr[regnum], data); |
| 1390 | } |
| 1391 | } |
| 1392 | |
| 1393 | /* STMY r1, r3, d2(b2) --- store multiple (long-displacement version) */ |
| 1394 | else if (word_size == 4 |
| 1395 | && is_rsy (insn, op1_stmy, op2_stmy, &r1, &r3, &d2, &b2)) |
| 1396 | { |
| 1397 | int regnum; |
| 1398 | int offset; |
| 1399 | struct prologue_value addr; |
| 1400 | |
| 1401 | for (regnum = r1, offset = 0; |
| 1402 | regnum <= r3; |
| 1403 | regnum++, offset += 4) |
| 1404 | { |
| 1405 | compute_x_addr (&addr, data->gpr, d2 + offset, 0, b2); |
| 1406 | s390_store (&addr, 4, &data->gpr[regnum], data); |
| 1407 | } |
| 1408 | } |
| 1409 | |
| 1410 | /* STMG r1, r3, d2(b2) --- store multiple (64-bit version) */ |
| 1411 | else if (word_size == 8 |
| 1412 | && is_rsy (insn, op1_stmg, op2_stmg, &r1, &r3, &d2, &b2)) |
| 1413 | { |
| 1414 | int regnum; |
| 1415 | int offset; |
| 1416 | struct prologue_value addr; |
| 1417 | |
| 1418 | for (regnum = r1, offset = 0; |
| 1419 | regnum <= r3; |
| 1420 | regnum++, offset += 8) |
| 1421 | { |
| 1422 | compute_x_addr (&addr, data->gpr, d2 + offset, 0, b2); |
| 1423 | s390_store (&addr, 8, &data->gpr[regnum], data); |
| 1424 | } |
| 1425 | } |
| 1426 | |
| 1427 | /* AHI r1, i2 --- add halfword immediate */ |
| 1428 | else if (word_size == 4 |
| 1429 | && is_ri (insn, op1_ahi, op2_ahi, &r1, &i2)) |
| 1430 | pv_add_constant (&data->gpr[r1], i2); |
| 1431 | |
| 1432 | /* AGHI r1, i2 --- add halfword immediate (64-bit version) */ |
| 1433 | else if (word_size == 8 |
| 1434 | && is_ri (insn, op1_aghi, op2_aghi, &r1, &i2)) |
| 1435 | pv_add_constant (&data->gpr[r1], i2); |
| 1436 | |
| 1437 | /* AR r1, r2 -- add register */ |
| 1438 | else if (word_size == 4 |
| 1439 | && is_rr (insn, op_ar, &r1, &r2)) |
| 1440 | pv_add (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); |
| 1441 | |
| 1442 | /* AGR r1, r2 -- add register (64-bit version) */ |
| 1443 | else if (word_size == 8 |
| 1444 | && is_rre (insn, op_agr, &r1, &r2)) |
| 1445 | pv_add (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); |
| 1446 | |
| 1447 | /* A r1, d2(x2, b2) -- add */ |
| 1448 | else if (word_size == 4 |
| 1449 | && is_rx (insn, op_a, &r1, &d2, &x2, &b2)) |
| 1450 | { |
| 1451 | struct prologue_value addr; |
| 1452 | struct prologue_value value; |
| 1453 | |
| 1454 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1455 | s390_load (&addr, 4, &value, data); |
| 1456 | |
| 1457 | pv_add (&data->gpr[r1], &data->gpr[r1], &value); |
| 1458 | } |
| 1459 | |
| 1460 | /* AY r1, d2(x2, b2) -- add (long-displacement version) */ |
| 1461 | else if (word_size == 4 |
| 1462 | && is_rxy (insn, op1_ay, op2_ay, &r1, &d2, &x2, &b2)) |
| 1463 | { |
| 1464 | struct prologue_value addr; |
| 1465 | struct prologue_value value; |
| 1466 | |
| 1467 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1468 | s390_load (&addr, 4, &value, data); |
| 1469 | |
| 1470 | pv_add (&data->gpr[r1], &data->gpr[r1], &value); |
| 1471 | } |
| 1472 | |
| 1473 | /* AG r1, d2(x2, b2) -- add (64-bit version) */ |
| 1474 | else if (word_size == 8 |
| 1475 | && is_rxy (insn, op1_ag, op2_ag, &r1, &d2, &x2, &b2)) |
| 1476 | { |
| 1477 | struct prologue_value addr; |
| 1478 | struct prologue_value value; |
| 1479 | |
| 1480 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1481 | s390_load (&addr, 8, &value, data); |
| 1482 | |
| 1483 | pv_add (&data->gpr[r1], &data->gpr[r1], &value); |
| 1484 | } |
| 1485 | |
| 1486 | /* SR r1, r2 -- subtract register */ |
| 1487 | else if (word_size == 4 |
| 1488 | && is_rr (insn, op_sr, &r1, &r2)) |
| 1489 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); |
| 1490 | |
| 1491 | /* SGR r1, r2 -- subtract register (64-bit version) */ |
| 1492 | else if (word_size == 8 |
| 1493 | && is_rre (insn, op_sgr, &r1, &r2)) |
| 1494 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); |
| 1495 | |
| 1496 | /* S r1, d2(x2, b2) -- subtract */ |
| 1497 | else if (word_size == 4 |
| 1498 | && is_rx (insn, op_s, &r1, &d2, &x2, &b2)) |
| 1499 | { |
| 1500 | struct prologue_value addr; |
| 1501 | struct prologue_value value; |
| 1502 | |
| 1503 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1504 | s390_load (&addr, 4, &value, data); |
| 1505 | |
| 1506 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &value); |
| 1507 | } |
| 1508 | |
| 1509 | /* SY r1, d2(x2, b2) -- subtract (long-displacement version) */ |
| 1510 | else if (word_size == 4 |
| 1511 | && is_rxy (insn, op1_sy, op2_sy, &r1, &d2, &x2, &b2)) |
| 1512 | { |
| 1513 | struct prologue_value addr; |
| 1514 | struct prologue_value value; |
| 1515 | |
| 1516 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1517 | s390_load (&addr, 4, &value, data); |
| 1518 | |
| 1519 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &value); |
| 1520 | } |
| 1521 | |
| 1522 | /* SG r1, d2(x2, b2) -- subtract (64-bit version) */ |
| 1523 | else if (word_size == 8 |
| 1524 | && is_rxy (insn, op1_sg, op2_sg, &r1, &d2, &x2, &b2)) |
| 1525 | { |
| 1526 | struct prologue_value addr; |
| 1527 | struct prologue_value value; |
| 1528 | |
| 1529 | compute_x_addr (&addr, data->gpr, d2, x2, b2); |
| 1530 | s390_load (&addr, 8, &value, data); |
| 1531 | |
| 1532 | pv_subtract (&data->gpr[r1], &data->gpr[r1], &value); |
| 1533 | } |
| 1534 | |
| 1535 | /* NR r1, r2 --- logical and */ |
| 1536 | else if (word_size == 4 |
| 1537 | && is_rr (insn, op_nr, &r1, &r2)) |
| 1538 | pv_logical_and (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); |
| 1539 | |
| 1540 | /* NGR r1, r2 >--- logical and (64-bit version) */ |
| 1541 | else if (word_size == 8 |
| 1542 | && is_rre (insn, op_ngr, &r1, &r2)) |
| 1543 | pv_logical_and (&data->gpr[r1], &data->gpr[r1], &data->gpr[r2]); |
| 1544 | |
| 1545 | /* LA r1, d2(x2, b2) --- load address */ |
| 1546 | else if (is_rx (insn, op_la, &r1, &d2, &x2, &b2)) |
| 1547 | compute_x_addr (&data->gpr[r1], data->gpr, d2, x2, b2); |
| 1548 | |
| 1549 | /* LAY r1, d2(x2, b2) --- load address (long-displacement version) */ |
| 1550 | else if (is_rxy (insn, op1_lay, op2_lay, &r1, &d2, &x2, &b2)) |
| 1551 | compute_x_addr (&data->gpr[r1], data->gpr, d2, x2, b2); |
| 1552 | |
| 1553 | /* LARL r1, i2 --- load address relative long */ |
| 1554 | else if (is_ril (insn, op1_larl, op2_larl, &r1, &i2)) |
| 1555 | pv_set_to_constant (&data->gpr[r1], pc + i2 * 2); |
| 1556 | |
| 1557 | /* BASR r1, 0 --- branch and save |
| 1558 | Since r2 is zero, this saves the PC in r1, but doesn't branch. */ |
| 1559 | else if (is_rr (insn, op_basr, &r1, &r2) |
| 1560 | && r2 == 0) |
| 1561 | pv_set_to_constant (&data->gpr[r1], next_pc); |
| 1562 | |
| 1563 | /* BRAS r1, i2 --- branch relative and save */ |
| 1564 | else if (is_ri (insn, op1_bras, op2_bras, &r1, &i2)) |
| 1565 | { |
| 1566 | pv_set_to_constant (&data->gpr[r1], next_pc); |
| 1567 | next_pc = pc + i2 * 2; |
| 1568 | |
| 1569 | /* We'd better not interpret any backward branches. We'll |
| 1570 | never terminate. */ |
| 1571 | if (next_pc <= pc) |
| 1572 | break; |
| 1573 | } |
| 1574 | |
| 1575 | /* Terminate search when hitting any other branch instruction. */ |
| 1576 | else if (is_rr (insn, op_basr, &r1, &r2) |
| 1577 | || is_rx (insn, op_bas, &r1, &d2, &x2, &b2) |
| 1578 | || is_rr (insn, op_bcr, &r1, &r2) |
| 1579 | || is_rx (insn, op_bc, &r1, &d2, &x2, &b2) |
| 1580 | || is_ri (insn, op1_brc, op2_brc, &r1, &i2) |
| 1581 | || is_ril (insn, op1_brcl, op2_brcl, &r1, &i2) |
| 1582 | || is_ril (insn, op1_brasl, op2_brasl, &r2, &i2)) |
| 1583 | break; |
| 1584 | |
| 1585 | else |
| 1586 | /* An instruction we don't know how to simulate. The only |
| 1587 | safe thing to do would be to set every value we're tracking |
| 1588 | to 'unknown'. Instead, we'll be optimistic: we assume that |
| 1589 | we *can* interpret every instruction that the compiler uses |
| 1590 | to manipulate any of the data we're interested in here -- |
| 1591 | then we can just ignore anything else. */ |
| 1592 | ; |
| 1593 | |
| 1594 | /* Record the address after the last instruction that changed |
| 1595 | the FP, SP, or backlink. Ignore instructions that changed |
| 1596 | them back to their original values --- those are probably |
| 1597 | restore instructions. (The back chain is never restored, |
| 1598 | just popped.) */ |
| 1599 | { |
| 1600 | struct prologue_value *sp = &data->gpr[S390_SP_REGNUM - S390_R0_REGNUM]; |
| 1601 | struct prologue_value *fp = &data->gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; |
| 1602 | |
| 1603 | if ((! pv_is_identical (&pre_insn_sp, sp) |
| 1604 | && ! pv_is_register (sp, S390_SP_REGNUM, 0)) |
| 1605 | || (! pv_is_identical (&pre_insn_fp, fp) |
| 1606 | && ! pv_is_register (fp, S390_FRAME_REGNUM, 0)) |
| 1607 | || pre_insn_back_chain_saved_p != data->back_chain_saved_p) |
| 1608 | result = next_pc; |
| 1609 | } |
| 1610 | } |
| 1611 | |
| 1612 | return result; |
| 1613 | } |
| 1614 | |
| 1615 | /* Advance PC across any function entry prologue instructions to reach |
| 1616 | some "real" code. */ |
| 1617 | static CORE_ADDR |
| 1618 | s390_skip_prologue (CORE_ADDR pc) |
| 1619 | { |
| 1620 | struct s390_prologue_data data; |
| 1621 | CORE_ADDR skip_pc; |
| 1622 | skip_pc = s390_analyze_prologue (current_gdbarch, pc, (CORE_ADDR)-1, &data); |
| 1623 | return skip_pc ? skip_pc : pc; |
| 1624 | } |
| 1625 | |
| 1626 | /* Return true if we are in the functin's epilogue, i.e. after the |
| 1627 | instruction that destroyed the function's stack frame. */ |
| 1628 | static int |
| 1629 | s390_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc) |
| 1630 | { |
| 1631 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 1632 | |
| 1633 | /* In frameless functions, there's not frame to destroy and thus |
| 1634 | we don't care about the epilogue. |
| 1635 | |
| 1636 | In functions with frame, the epilogue sequence is a pair of |
| 1637 | a LM-type instruction that restores (amongst others) the |
| 1638 | return register %r14 and the stack pointer %r15, followed |
| 1639 | by a branch 'br %r14' --or equivalent-- that effects the |
| 1640 | actual return. |
| 1641 | |
| 1642 | In that situation, this function needs to return 'true' in |
| 1643 | exactly one case: when pc points to that branch instruction. |
| 1644 | |
| 1645 | Thus we try to disassemble the one instructions immediately |
| 1646 | preceeding pc and check whether it is an LM-type instruction |
| 1647 | modifying the stack pointer. |
| 1648 | |
| 1649 | Note that disassembling backwards is not reliable, so there |
| 1650 | is a slight chance of false positives here ... */ |
| 1651 | |
| 1652 | bfd_byte insn[6]; |
| 1653 | unsigned int r1, r3, b2; |
| 1654 | int d2; |
| 1655 | |
| 1656 | if (word_size == 4 |
| 1657 | && !deprecated_read_memory_nobpt (pc - 4, insn, 4) |
| 1658 | && is_rs (insn, op_lm, &r1, &r3, &d2, &b2) |
| 1659 | && r3 == S390_SP_REGNUM - S390_R0_REGNUM) |
| 1660 | return 1; |
| 1661 | |
| 1662 | if (word_size == 4 |
| 1663 | && !deprecated_read_memory_nobpt (pc - 6, insn, 6) |
| 1664 | && is_rsy (insn, op1_lmy, op2_lmy, &r1, &r3, &d2, &b2) |
| 1665 | && r3 == S390_SP_REGNUM - S390_R0_REGNUM) |
| 1666 | return 1; |
| 1667 | |
| 1668 | if (word_size == 8 |
| 1669 | && !deprecated_read_memory_nobpt (pc - 6, insn, 6) |
| 1670 | && is_rsy (insn, op1_lmg, op2_lmg, &r1, &r3, &d2, &b2) |
| 1671 | && r3 == S390_SP_REGNUM - S390_R0_REGNUM) |
| 1672 | return 1; |
| 1673 | |
| 1674 | return 0; |
| 1675 | } |
| 1676 | |
| 1677 | |
| 1678 | /* Normal stack frames. */ |
| 1679 | |
| 1680 | struct s390_unwind_cache { |
| 1681 | |
| 1682 | CORE_ADDR func; |
| 1683 | CORE_ADDR frame_base; |
| 1684 | CORE_ADDR local_base; |
| 1685 | |
| 1686 | struct trad_frame_saved_reg *saved_regs; |
| 1687 | }; |
| 1688 | |
| 1689 | static int |
| 1690 | s390_prologue_frame_unwind_cache (struct frame_info *next_frame, |
| 1691 | struct s390_unwind_cache *info) |
| 1692 | { |
| 1693 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 1694 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1695 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 1696 | struct s390_prologue_data data; |
| 1697 | struct prologue_value *fp = &data.gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; |
| 1698 | struct prologue_value *sp = &data.gpr[S390_SP_REGNUM - S390_R0_REGNUM]; |
| 1699 | int i; |
| 1700 | CORE_ADDR cfa; |
| 1701 | CORE_ADDR func; |
| 1702 | CORE_ADDR result; |
| 1703 | ULONGEST reg; |
| 1704 | CORE_ADDR prev_sp; |
| 1705 | int frame_pointer; |
| 1706 | int size; |
| 1707 | |
| 1708 | /* Try to find the function start address. If we can't find it, we don't |
| 1709 | bother searching for it -- with modern compilers this would be mostly |
| 1710 | pointless anyway. Trust that we'll either have valid DWARF-2 CFI data |
| 1711 | or else a valid backchain ... */ |
| 1712 | func = frame_func_unwind (next_frame); |
| 1713 | if (!func) |
| 1714 | return 0; |
| 1715 | |
| 1716 | /* Try to analyze the prologue. */ |
| 1717 | result = s390_analyze_prologue (gdbarch, func, |
| 1718 | frame_pc_unwind (next_frame), &data); |
| 1719 | if (!result) |
| 1720 | return 0; |
| 1721 | |
| 1722 | /* If this was successful, we should have found the instruction that |
| 1723 | sets the stack pointer register to the previous value of the stack |
| 1724 | pointer minus the frame size. */ |
| 1725 | if (sp->kind != pv_register || sp->reg != S390_SP_REGNUM) |
| 1726 | return 0; |
| 1727 | |
| 1728 | /* A frame size of zero at this point can mean either a real |
| 1729 | frameless function, or else a failure to find the prologue. |
| 1730 | Perform some sanity checks to verify we really have a |
| 1731 | frameless function. */ |
| 1732 | if (sp->k == 0) |
| 1733 | { |
| 1734 | /* If the next frame is a NORMAL_FRAME, this frame *cannot* have frame |
| 1735 | size zero. This is only possible if the next frame is a sentinel |
| 1736 | frame, a dummy frame, or a signal trampoline frame. */ |
| 1737 | /* FIXME: cagney/2004-05-01: This sanity check shouldn't be |
| 1738 | needed, instead the code should simpliy rely on its |
| 1739 | analysis. */ |
| 1740 | if (get_frame_type (next_frame) == NORMAL_FRAME) |
| 1741 | return 0; |
| 1742 | |
| 1743 | /* If we really have a frameless function, %r14 must be valid |
| 1744 | -- in particular, it must point to a different function. */ |
| 1745 | reg = frame_unwind_register_unsigned (next_frame, S390_RETADDR_REGNUM); |
| 1746 | reg = gdbarch_addr_bits_remove (gdbarch, reg) - 1; |
| 1747 | if (get_pc_function_start (reg) == func) |
| 1748 | { |
| 1749 | /* However, there is one case where it *is* valid for %r14 |
| 1750 | to point to the same function -- if this is a recursive |
| 1751 | call, and we have stopped in the prologue *before* the |
| 1752 | stack frame was allocated. |
| 1753 | |
| 1754 | Recognize this case by looking ahead a bit ... */ |
| 1755 | |
| 1756 | struct s390_prologue_data data2; |
| 1757 | struct prologue_value *sp = &data2.gpr[S390_SP_REGNUM - S390_R0_REGNUM]; |
| 1758 | |
| 1759 | if (!(s390_analyze_prologue (gdbarch, func, (CORE_ADDR)-1, &data2) |
| 1760 | && sp->kind == pv_register |
| 1761 | && sp->reg == S390_SP_REGNUM |
| 1762 | && sp->k != 0)) |
| 1763 | return 0; |
| 1764 | } |
| 1765 | } |
| 1766 | |
| 1767 | |
| 1768 | /* OK, we've found valid prologue data. */ |
| 1769 | size = -sp->k; |
| 1770 | |
| 1771 | /* If the frame pointer originally also holds the same value |
| 1772 | as the stack pointer, we're probably using it. If it holds |
| 1773 | some other value -- even a constant offset -- it is most |
| 1774 | likely used as temp register. */ |
| 1775 | if (pv_is_identical (sp, fp)) |
| 1776 | frame_pointer = S390_FRAME_REGNUM; |
| 1777 | else |
| 1778 | frame_pointer = S390_SP_REGNUM; |
| 1779 | |
| 1780 | /* If we've detected a function with stack frame, we'll still have to |
| 1781 | treat it as frameless if we're currently within the function epilog |
| 1782 | code at a point where the frame pointer has already been restored. |
| 1783 | This can only happen in an innermost frame. */ |
| 1784 | /* FIXME: cagney/2004-05-01: This sanity check shouldn't be needed, |
| 1785 | instead the code should simpliy rely on its analysis. */ |
| 1786 | if (size > 0 && get_frame_type (next_frame) != NORMAL_FRAME) |
| 1787 | { |
| 1788 | /* See the comment in s390_in_function_epilogue_p on why this is |
| 1789 | not completely reliable ... */ |
| 1790 | if (s390_in_function_epilogue_p (gdbarch, frame_pc_unwind (next_frame))) |
| 1791 | { |
| 1792 | memset (&data, 0, sizeof (data)); |
| 1793 | size = 0; |
| 1794 | frame_pointer = S390_SP_REGNUM; |
| 1795 | } |
| 1796 | } |
| 1797 | |
| 1798 | /* Once we know the frame register and the frame size, we can unwind |
| 1799 | the current value of the frame register from the next frame, and |
| 1800 | add back the frame size to arrive that the previous frame's |
| 1801 | stack pointer value. */ |
| 1802 | prev_sp = frame_unwind_register_unsigned (next_frame, frame_pointer) + size; |
| 1803 | cfa = prev_sp + 16*word_size + 32; |
| 1804 | |
| 1805 | /* Record the addresses of all register spill slots the prologue parser |
| 1806 | has recognized. Consider only registers defined as call-saved by the |
| 1807 | ABI; for call-clobbered registers the parser may have recognized |
| 1808 | spurious stores. */ |
| 1809 | |
| 1810 | for (i = 6; i <= 15; i++) |
| 1811 | if (data.gpr_slot[i] != 0) |
| 1812 | info->saved_regs[S390_R0_REGNUM + i].addr = cfa - data.gpr_slot[i]; |
| 1813 | |
| 1814 | switch (tdep->abi) |
| 1815 | { |
| 1816 | case ABI_LINUX_S390: |
| 1817 | if (data.fpr_slot[4] != 0) |
| 1818 | info->saved_regs[S390_F4_REGNUM].addr = cfa - data.fpr_slot[4]; |
| 1819 | if (data.fpr_slot[6] != 0) |
| 1820 | info->saved_regs[S390_F6_REGNUM].addr = cfa - data.fpr_slot[6]; |
| 1821 | break; |
| 1822 | |
| 1823 | case ABI_LINUX_ZSERIES: |
| 1824 | for (i = 8; i <= 15; i++) |
| 1825 | if (data.fpr_slot[i] != 0) |
| 1826 | info->saved_regs[S390_F0_REGNUM + i].addr = cfa - data.fpr_slot[i]; |
| 1827 | break; |
| 1828 | } |
| 1829 | |
| 1830 | /* Function return will set PC to %r14. */ |
| 1831 | info->saved_regs[S390_PC_REGNUM] = info->saved_regs[S390_RETADDR_REGNUM]; |
| 1832 | |
| 1833 | /* In frameless functions, we unwind simply by moving the return |
| 1834 | address to the PC. However, if we actually stored to the |
| 1835 | save area, use that -- we might only think the function frameless |
| 1836 | because we're in the middle of the prologue ... */ |
| 1837 | if (size == 0 |
| 1838 | && !trad_frame_addr_p (info->saved_regs, S390_PC_REGNUM)) |
| 1839 | { |
| 1840 | info->saved_regs[S390_PC_REGNUM].realreg = S390_RETADDR_REGNUM; |
| 1841 | } |
| 1842 | |
| 1843 | /* Another sanity check: unless this is a frameless function, |
| 1844 | we should have found spill slots for SP and PC. |
| 1845 | If not, we cannot unwind further -- this happens e.g. in |
| 1846 | libc's thread_start routine. */ |
| 1847 | if (size > 0) |
| 1848 | { |
| 1849 | if (!trad_frame_addr_p (info->saved_regs, S390_SP_REGNUM) |
| 1850 | || !trad_frame_addr_p (info->saved_regs, S390_PC_REGNUM)) |
| 1851 | prev_sp = -1; |
| 1852 | } |
| 1853 | |
| 1854 | /* We use the current value of the frame register as local_base, |
| 1855 | and the top of the register save area as frame_base. */ |
| 1856 | if (prev_sp != -1) |
| 1857 | { |
| 1858 | info->frame_base = prev_sp + 16*word_size + 32; |
| 1859 | info->local_base = prev_sp - size; |
| 1860 | } |
| 1861 | |
| 1862 | info->func = func; |
| 1863 | return 1; |
| 1864 | } |
| 1865 | |
| 1866 | static void |
| 1867 | s390_backchain_frame_unwind_cache (struct frame_info *next_frame, |
| 1868 | struct s390_unwind_cache *info) |
| 1869 | { |
| 1870 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 1871 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 1872 | CORE_ADDR backchain; |
| 1873 | ULONGEST reg; |
| 1874 | LONGEST sp; |
| 1875 | |
| 1876 | /* Get the backchain. */ |
| 1877 | reg = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); |
| 1878 | backchain = read_memory_unsigned_integer (reg, word_size); |
| 1879 | |
| 1880 | /* A zero backchain terminates the frame chain. As additional |
| 1881 | sanity check, let's verify that the spill slot for SP in the |
| 1882 | save area pointed to by the backchain in fact links back to |
| 1883 | the save area. */ |
| 1884 | if (backchain != 0 |
| 1885 | && safe_read_memory_integer (backchain + 15*word_size, word_size, &sp) |
| 1886 | && (CORE_ADDR)sp == backchain) |
| 1887 | { |
| 1888 | /* We don't know which registers were saved, but it will have |
| 1889 | to be at least %r14 and %r15. This will allow us to continue |
| 1890 | unwinding, but other prev-frame registers may be incorrect ... */ |
| 1891 | info->saved_regs[S390_SP_REGNUM].addr = backchain + 15*word_size; |
| 1892 | info->saved_regs[S390_RETADDR_REGNUM].addr = backchain + 14*word_size; |
| 1893 | |
| 1894 | /* Function return will set PC to %r14. */ |
| 1895 | info->saved_regs[S390_PC_REGNUM] = info->saved_regs[S390_RETADDR_REGNUM]; |
| 1896 | |
| 1897 | /* We use the current value of the frame register as local_base, |
| 1898 | and the top of the register save area as frame_base. */ |
| 1899 | info->frame_base = backchain + 16*word_size + 32; |
| 1900 | info->local_base = reg; |
| 1901 | } |
| 1902 | |
| 1903 | info->func = frame_pc_unwind (next_frame); |
| 1904 | } |
| 1905 | |
| 1906 | static struct s390_unwind_cache * |
| 1907 | s390_frame_unwind_cache (struct frame_info *next_frame, |
| 1908 | void **this_prologue_cache) |
| 1909 | { |
| 1910 | struct s390_unwind_cache *info; |
| 1911 | if (*this_prologue_cache) |
| 1912 | return *this_prologue_cache; |
| 1913 | |
| 1914 | info = FRAME_OBSTACK_ZALLOC (struct s390_unwind_cache); |
| 1915 | *this_prologue_cache = info; |
| 1916 | info->saved_regs = trad_frame_alloc_saved_regs (next_frame); |
| 1917 | info->func = -1; |
| 1918 | info->frame_base = -1; |
| 1919 | info->local_base = -1; |
| 1920 | |
| 1921 | /* Try to use prologue analysis to fill the unwind cache. |
| 1922 | If this fails, fall back to reading the stack backchain. */ |
| 1923 | if (!s390_prologue_frame_unwind_cache (next_frame, info)) |
| 1924 | s390_backchain_frame_unwind_cache (next_frame, info); |
| 1925 | |
| 1926 | return info; |
| 1927 | } |
| 1928 | |
| 1929 | static void |
| 1930 | s390_frame_this_id (struct frame_info *next_frame, |
| 1931 | void **this_prologue_cache, |
| 1932 | struct frame_id *this_id) |
| 1933 | { |
| 1934 | struct s390_unwind_cache *info |
| 1935 | = s390_frame_unwind_cache (next_frame, this_prologue_cache); |
| 1936 | |
| 1937 | if (info->frame_base == -1) |
| 1938 | return; |
| 1939 | |
| 1940 | *this_id = frame_id_build (info->frame_base, info->func); |
| 1941 | } |
| 1942 | |
| 1943 | static void |
| 1944 | s390_frame_prev_register (struct frame_info *next_frame, |
| 1945 | void **this_prologue_cache, |
| 1946 | int regnum, int *optimizedp, |
| 1947 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 1948 | int *realnump, void *bufferp) |
| 1949 | { |
| 1950 | struct s390_unwind_cache *info |
| 1951 | = s390_frame_unwind_cache (next_frame, this_prologue_cache); |
| 1952 | trad_frame_get_prev_register (next_frame, info->saved_regs, regnum, |
| 1953 | optimizedp, lvalp, addrp, realnump, bufferp); |
| 1954 | } |
| 1955 | |
| 1956 | static const struct frame_unwind s390_frame_unwind = { |
| 1957 | NORMAL_FRAME, |
| 1958 | s390_frame_this_id, |
| 1959 | s390_frame_prev_register |
| 1960 | }; |
| 1961 | |
| 1962 | static const struct frame_unwind * |
| 1963 | s390_frame_sniffer (struct frame_info *next_frame) |
| 1964 | { |
| 1965 | return &s390_frame_unwind; |
| 1966 | } |
| 1967 | |
| 1968 | |
| 1969 | /* Code stubs and their stack frames. For things like PLTs and NULL |
| 1970 | function calls (where there is no true frame and the return address |
| 1971 | is in the RETADDR register). */ |
| 1972 | |
| 1973 | struct s390_stub_unwind_cache |
| 1974 | { |
| 1975 | CORE_ADDR frame_base; |
| 1976 | struct trad_frame_saved_reg *saved_regs; |
| 1977 | }; |
| 1978 | |
| 1979 | static struct s390_stub_unwind_cache * |
| 1980 | s390_stub_frame_unwind_cache (struct frame_info *next_frame, |
| 1981 | void **this_prologue_cache) |
| 1982 | { |
| 1983 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 1984 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 1985 | struct s390_stub_unwind_cache *info; |
| 1986 | ULONGEST reg; |
| 1987 | |
| 1988 | if (*this_prologue_cache) |
| 1989 | return *this_prologue_cache; |
| 1990 | |
| 1991 | info = FRAME_OBSTACK_ZALLOC (struct s390_stub_unwind_cache); |
| 1992 | *this_prologue_cache = info; |
| 1993 | info->saved_regs = trad_frame_alloc_saved_regs (next_frame); |
| 1994 | |
| 1995 | /* The return address is in register %r14. */ |
| 1996 | info->saved_regs[S390_PC_REGNUM].realreg = S390_RETADDR_REGNUM; |
| 1997 | |
| 1998 | /* Retrieve stack pointer and determine our frame base. */ |
| 1999 | reg = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); |
| 2000 | info->frame_base = reg + 16*word_size + 32; |
| 2001 | |
| 2002 | return info; |
| 2003 | } |
| 2004 | |
| 2005 | static void |
| 2006 | s390_stub_frame_this_id (struct frame_info *next_frame, |
| 2007 | void **this_prologue_cache, |
| 2008 | struct frame_id *this_id) |
| 2009 | { |
| 2010 | struct s390_stub_unwind_cache *info |
| 2011 | = s390_stub_frame_unwind_cache (next_frame, this_prologue_cache); |
| 2012 | *this_id = frame_id_build (info->frame_base, frame_pc_unwind (next_frame)); |
| 2013 | } |
| 2014 | |
| 2015 | static void |
| 2016 | s390_stub_frame_prev_register (struct frame_info *next_frame, |
| 2017 | void **this_prologue_cache, |
| 2018 | int regnum, int *optimizedp, |
| 2019 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 2020 | int *realnump, void *bufferp) |
| 2021 | { |
| 2022 | struct s390_stub_unwind_cache *info |
| 2023 | = s390_stub_frame_unwind_cache (next_frame, this_prologue_cache); |
| 2024 | trad_frame_get_prev_register (next_frame, info->saved_regs, regnum, |
| 2025 | optimizedp, lvalp, addrp, realnump, bufferp); |
| 2026 | } |
| 2027 | |
| 2028 | static const struct frame_unwind s390_stub_frame_unwind = { |
| 2029 | NORMAL_FRAME, |
| 2030 | s390_stub_frame_this_id, |
| 2031 | s390_stub_frame_prev_register |
| 2032 | }; |
| 2033 | |
| 2034 | static const struct frame_unwind * |
| 2035 | s390_stub_frame_sniffer (struct frame_info *next_frame) |
| 2036 | { |
| 2037 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
| 2038 | bfd_byte insn[S390_MAX_INSTR_SIZE]; |
| 2039 | |
| 2040 | /* If the current PC points to non-readable memory, we assume we |
| 2041 | have trapped due to an invalid function pointer call. We handle |
| 2042 | the non-existing current function like a PLT stub. */ |
| 2043 | if (in_plt_section (pc, NULL) |
| 2044 | || s390_readinstruction (insn, pc) < 0) |
| 2045 | return &s390_stub_frame_unwind; |
| 2046 | return NULL; |
| 2047 | } |
| 2048 | |
| 2049 | |
| 2050 | /* Signal trampoline stack frames. */ |
| 2051 | |
| 2052 | struct s390_sigtramp_unwind_cache { |
| 2053 | CORE_ADDR frame_base; |
| 2054 | struct trad_frame_saved_reg *saved_regs; |
| 2055 | }; |
| 2056 | |
| 2057 | static struct s390_sigtramp_unwind_cache * |
| 2058 | s390_sigtramp_frame_unwind_cache (struct frame_info *next_frame, |
| 2059 | void **this_prologue_cache) |
| 2060 | { |
| 2061 | struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| 2062 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 2063 | struct s390_sigtramp_unwind_cache *info; |
| 2064 | ULONGEST this_sp, prev_sp; |
| 2065 | CORE_ADDR next_ra, next_cfa, sigreg_ptr; |
| 2066 | int i; |
| 2067 | |
| 2068 | if (*this_prologue_cache) |
| 2069 | return *this_prologue_cache; |
| 2070 | |
| 2071 | info = FRAME_OBSTACK_ZALLOC (struct s390_sigtramp_unwind_cache); |
| 2072 | *this_prologue_cache = info; |
| 2073 | info->saved_regs = trad_frame_alloc_saved_regs (next_frame); |
| 2074 | |
| 2075 | this_sp = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); |
| 2076 | next_ra = frame_pc_unwind (next_frame); |
| 2077 | next_cfa = this_sp + 16*word_size + 32; |
| 2078 | |
| 2079 | /* New-style RT frame: |
| 2080 | retcode + alignment (8 bytes) |
| 2081 | siginfo (128 bytes) |
| 2082 | ucontext (contains sigregs at offset 5 words) */ |
| 2083 | if (next_ra == next_cfa) |
| 2084 | { |
| 2085 | sigreg_ptr = next_cfa + 8 + 128 + align_up (5*word_size, 8); |
| 2086 | } |
| 2087 | |
| 2088 | /* Old-style RT frame and all non-RT frames: |
| 2089 | old signal mask (8 bytes) |
| 2090 | pointer to sigregs */ |
| 2091 | else |
| 2092 | { |
| 2093 | sigreg_ptr = read_memory_unsigned_integer (next_cfa + 8, word_size); |
| 2094 | } |
| 2095 | |
| 2096 | /* The sigregs structure looks like this: |
| 2097 | long psw_mask; |
| 2098 | long psw_addr; |
| 2099 | long gprs[16]; |
| 2100 | int acrs[16]; |
| 2101 | int fpc; |
| 2102 | int __pad; |
| 2103 | double fprs[16]; */ |
| 2104 | |
| 2105 | /* Let's ignore the PSW mask, it will not be restored anyway. */ |
| 2106 | sigreg_ptr += word_size; |
| 2107 | |
| 2108 | /* Next comes the PSW address. */ |
| 2109 | info->saved_regs[S390_PC_REGNUM].addr = sigreg_ptr; |
| 2110 | sigreg_ptr += word_size; |
| 2111 | |
| 2112 | /* Then the GPRs. */ |
| 2113 | for (i = 0; i < 16; i++) |
| 2114 | { |
| 2115 | info->saved_regs[S390_R0_REGNUM + i].addr = sigreg_ptr; |
| 2116 | sigreg_ptr += word_size; |
| 2117 | } |
| 2118 | |
| 2119 | /* Then the ACRs. */ |
| 2120 | for (i = 0; i < 16; i++) |
| 2121 | { |
| 2122 | info->saved_regs[S390_A0_REGNUM + i].addr = sigreg_ptr; |
| 2123 | sigreg_ptr += 4; |
| 2124 | } |
| 2125 | |
| 2126 | /* The floating-point control word. */ |
| 2127 | info->saved_regs[S390_FPC_REGNUM].addr = sigreg_ptr; |
| 2128 | sigreg_ptr += 8; |
| 2129 | |
| 2130 | /* And finally the FPRs. */ |
| 2131 | for (i = 0; i < 16; i++) |
| 2132 | { |
| 2133 | info->saved_regs[S390_F0_REGNUM + i].addr = sigreg_ptr; |
| 2134 | sigreg_ptr += 8; |
| 2135 | } |
| 2136 | |
| 2137 | /* Restore the previous frame's SP. */ |
| 2138 | prev_sp = read_memory_unsigned_integer ( |
| 2139 | info->saved_regs[S390_SP_REGNUM].addr, |
| 2140 | word_size); |
| 2141 | |
| 2142 | /* Determine our frame base. */ |
| 2143 | info->frame_base = prev_sp + 16*word_size + 32; |
| 2144 | |
| 2145 | return info; |
| 2146 | } |
| 2147 | |
| 2148 | static void |
| 2149 | s390_sigtramp_frame_this_id (struct frame_info *next_frame, |
| 2150 | void **this_prologue_cache, |
| 2151 | struct frame_id *this_id) |
| 2152 | { |
| 2153 | struct s390_sigtramp_unwind_cache *info |
| 2154 | = s390_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); |
| 2155 | *this_id = frame_id_build (info->frame_base, frame_pc_unwind (next_frame)); |
| 2156 | } |
| 2157 | |
| 2158 | static void |
| 2159 | s390_sigtramp_frame_prev_register (struct frame_info *next_frame, |
| 2160 | void **this_prologue_cache, |
| 2161 | int regnum, int *optimizedp, |
| 2162 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 2163 | int *realnump, void *bufferp) |
| 2164 | { |
| 2165 | struct s390_sigtramp_unwind_cache *info |
| 2166 | = s390_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); |
| 2167 | trad_frame_get_prev_register (next_frame, info->saved_regs, regnum, |
| 2168 | optimizedp, lvalp, addrp, realnump, bufferp); |
| 2169 | } |
| 2170 | |
| 2171 | static const struct frame_unwind s390_sigtramp_frame_unwind = { |
| 2172 | SIGTRAMP_FRAME, |
| 2173 | s390_sigtramp_frame_this_id, |
| 2174 | s390_sigtramp_frame_prev_register |
| 2175 | }; |
| 2176 | |
| 2177 | static const struct frame_unwind * |
| 2178 | s390_sigtramp_frame_sniffer (struct frame_info *next_frame) |
| 2179 | { |
| 2180 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
| 2181 | bfd_byte sigreturn[2]; |
| 2182 | |
| 2183 | if (deprecated_read_memory_nobpt (pc, sigreturn, 2)) |
| 2184 | return NULL; |
| 2185 | |
| 2186 | if (sigreturn[0] != 0x0a /* svc */) |
| 2187 | return NULL; |
| 2188 | |
| 2189 | if (sigreturn[1] != 119 /* sigreturn */ |
| 2190 | && sigreturn[1] != 173 /* rt_sigreturn */) |
| 2191 | return NULL; |
| 2192 | |
| 2193 | return &s390_sigtramp_frame_unwind; |
| 2194 | } |
| 2195 | |
| 2196 | |
| 2197 | /* Frame base handling. */ |
| 2198 | |
| 2199 | static CORE_ADDR |
| 2200 | s390_frame_base_address (struct frame_info *next_frame, void **this_cache) |
| 2201 | { |
| 2202 | struct s390_unwind_cache *info |
| 2203 | = s390_frame_unwind_cache (next_frame, this_cache); |
| 2204 | return info->frame_base; |
| 2205 | } |
| 2206 | |
| 2207 | static CORE_ADDR |
| 2208 | s390_local_base_address (struct frame_info *next_frame, void **this_cache) |
| 2209 | { |
| 2210 | struct s390_unwind_cache *info |
| 2211 | = s390_frame_unwind_cache (next_frame, this_cache); |
| 2212 | return info->local_base; |
| 2213 | } |
| 2214 | |
| 2215 | static const struct frame_base s390_frame_base = { |
| 2216 | &s390_frame_unwind, |
| 2217 | s390_frame_base_address, |
| 2218 | s390_local_base_address, |
| 2219 | s390_local_base_address |
| 2220 | }; |
| 2221 | |
| 2222 | static CORE_ADDR |
| 2223 | s390_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 2224 | { |
| 2225 | ULONGEST pc; |
| 2226 | pc = frame_unwind_register_unsigned (next_frame, S390_PC_REGNUM); |
| 2227 | return gdbarch_addr_bits_remove (gdbarch, pc); |
| 2228 | } |
| 2229 | |
| 2230 | static CORE_ADDR |
| 2231 | s390_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 2232 | { |
| 2233 | ULONGEST sp; |
| 2234 | sp = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); |
| 2235 | return gdbarch_addr_bits_remove (gdbarch, sp); |
| 2236 | } |
| 2237 | |
| 2238 | |
| 2239 | /* DWARF-2 frame support. */ |
| 2240 | |
| 2241 | static void |
| 2242 | s390_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum, |
| 2243 | struct dwarf2_frame_state_reg *reg) |
| 2244 | { |
| 2245 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 2246 | |
| 2247 | switch (tdep->abi) |
| 2248 | { |
| 2249 | case ABI_LINUX_S390: |
| 2250 | /* Call-saved registers. */ |
| 2251 | if ((regnum >= S390_R6_REGNUM && regnum <= S390_R15_REGNUM) |
| 2252 | || regnum == S390_F4_REGNUM |
| 2253 | || regnum == S390_F6_REGNUM) |
| 2254 | reg->how = DWARF2_FRAME_REG_SAME_VALUE; |
| 2255 | |
| 2256 | /* Call-clobbered registers. */ |
| 2257 | else if ((regnum >= S390_R0_REGNUM && regnum <= S390_R5_REGNUM) |
| 2258 | || (regnum >= S390_F0_REGNUM && regnum <= S390_F15_REGNUM |
| 2259 | && regnum != S390_F4_REGNUM && regnum != S390_F6_REGNUM)) |
| 2260 | reg->how = DWARF2_FRAME_REG_UNDEFINED; |
| 2261 | |
| 2262 | /* The return address column. */ |
| 2263 | else if (regnum == S390_PC_REGNUM) |
| 2264 | reg->how = DWARF2_FRAME_REG_RA; |
| 2265 | break; |
| 2266 | |
| 2267 | case ABI_LINUX_ZSERIES: |
| 2268 | /* Call-saved registers. */ |
| 2269 | if ((regnum >= S390_R6_REGNUM && regnum <= S390_R15_REGNUM) |
| 2270 | || (regnum >= S390_F8_REGNUM && regnum <= S390_F15_REGNUM)) |
| 2271 | reg->how = DWARF2_FRAME_REG_SAME_VALUE; |
| 2272 | |
| 2273 | /* Call-clobbered registers. */ |
| 2274 | else if ((regnum >= S390_R0_REGNUM && regnum <= S390_R5_REGNUM) |
| 2275 | || (regnum >= S390_F0_REGNUM && regnum <= S390_F7_REGNUM)) |
| 2276 | reg->how = DWARF2_FRAME_REG_UNDEFINED; |
| 2277 | |
| 2278 | /* The return address column. */ |
| 2279 | else if (regnum == S390_PC_REGNUM) |
| 2280 | reg->how = DWARF2_FRAME_REG_RA; |
| 2281 | break; |
| 2282 | } |
| 2283 | } |
| 2284 | |
| 2285 | |
| 2286 | /* Dummy function calls. */ |
| 2287 | |
| 2288 | /* Return non-zero if TYPE is an integer-like type, zero otherwise. |
| 2289 | "Integer-like" types are those that should be passed the way |
| 2290 | integers are: integers, enums, ranges, characters, and booleans. */ |
| 2291 | static int |
| 2292 | is_integer_like (struct type *type) |
| 2293 | { |
| 2294 | enum type_code code = TYPE_CODE (type); |
| 2295 | |
| 2296 | return (code == TYPE_CODE_INT |
| 2297 | || code == TYPE_CODE_ENUM |
| 2298 | || code == TYPE_CODE_RANGE |
| 2299 | || code == TYPE_CODE_CHAR |
| 2300 | || code == TYPE_CODE_BOOL); |
| 2301 | } |
| 2302 | |
| 2303 | /* Return non-zero if TYPE is a pointer-like type, zero otherwise. |
| 2304 | "Pointer-like" types are those that should be passed the way |
| 2305 | pointers are: pointers and references. */ |
| 2306 | static int |
| 2307 | is_pointer_like (struct type *type) |
| 2308 | { |
| 2309 | enum type_code code = TYPE_CODE (type); |
| 2310 | |
| 2311 | return (code == TYPE_CODE_PTR |
| 2312 | || code == TYPE_CODE_REF); |
| 2313 | } |
| 2314 | |
| 2315 | |
| 2316 | /* Return non-zero if TYPE is a `float singleton' or `double |
| 2317 | singleton', zero otherwise. |
| 2318 | |
| 2319 | A `T singleton' is a struct type with one member, whose type is |
| 2320 | either T or a `T singleton'. So, the following are all float |
| 2321 | singletons: |
| 2322 | |
| 2323 | struct { float x }; |
| 2324 | struct { struct { float x; } x; }; |
| 2325 | struct { struct { struct { float x; } x; } x; }; |
| 2326 | |
| 2327 | ... and so on. |
| 2328 | |
| 2329 | All such structures are passed as if they were floats or doubles, |
| 2330 | as the (revised) ABI says. */ |
| 2331 | static int |
| 2332 | is_float_singleton (struct type *type) |
| 2333 | { |
| 2334 | if (TYPE_CODE (type) == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1) |
| 2335 | { |
| 2336 | struct type *singleton_type = TYPE_FIELD_TYPE (type, 0); |
| 2337 | CHECK_TYPEDEF (singleton_type); |
| 2338 | |
| 2339 | return (TYPE_CODE (singleton_type) == TYPE_CODE_FLT |
| 2340 | || is_float_singleton (singleton_type)); |
| 2341 | } |
| 2342 | |
| 2343 | return 0; |
| 2344 | } |
| 2345 | |
| 2346 | |
| 2347 | /* Return non-zero if TYPE is a struct-like type, zero otherwise. |
| 2348 | "Struct-like" types are those that should be passed as structs are: |
| 2349 | structs and unions. |
| 2350 | |
| 2351 | As an odd quirk, not mentioned in the ABI, GCC passes float and |
| 2352 | double singletons as if they were a plain float, double, etc. (The |
| 2353 | corresponding union types are handled normally.) So we exclude |
| 2354 | those types here. *shrug* */ |
| 2355 | static int |
| 2356 | is_struct_like (struct type *type) |
| 2357 | { |
| 2358 | enum type_code code = TYPE_CODE (type); |
| 2359 | |
| 2360 | return (code == TYPE_CODE_UNION |
| 2361 | || (code == TYPE_CODE_STRUCT && ! is_float_singleton (type))); |
| 2362 | } |
| 2363 | |
| 2364 | |
| 2365 | /* Return non-zero if TYPE is a float-like type, zero otherwise. |
| 2366 | "Float-like" types are those that should be passed as |
| 2367 | floating-point values are. |
| 2368 | |
| 2369 | You'd think this would just be floats, doubles, long doubles, etc. |
| 2370 | But as an odd quirk, not mentioned in the ABI, GCC passes float and |
| 2371 | double singletons as if they were a plain float, double, etc. (The |
| 2372 | corresponding union types are handled normally.) So we include |
| 2373 | those types here. *shrug* */ |
| 2374 | static int |
| 2375 | is_float_like (struct type *type) |
| 2376 | { |
| 2377 | return (TYPE_CODE (type) == TYPE_CODE_FLT |
| 2378 | || is_float_singleton (type)); |
| 2379 | } |
| 2380 | |
| 2381 | |
| 2382 | static int |
| 2383 | is_power_of_two (unsigned int n) |
| 2384 | { |
| 2385 | return ((n & (n - 1)) == 0); |
| 2386 | } |
| 2387 | |
| 2388 | /* Return non-zero if TYPE should be passed as a pointer to a copy, |
| 2389 | zero otherwise. */ |
| 2390 | static int |
| 2391 | s390_function_arg_pass_by_reference (struct type *type) |
| 2392 | { |
| 2393 | unsigned length = TYPE_LENGTH (type); |
| 2394 | if (length > 8) |
| 2395 | return 1; |
| 2396 | |
| 2397 | /* FIXME: All complex and vector types are also returned by reference. */ |
| 2398 | return is_struct_like (type) && !is_power_of_two (length); |
| 2399 | } |
| 2400 | |
| 2401 | /* Return non-zero if TYPE should be passed in a float register |
| 2402 | if possible. */ |
| 2403 | static int |
| 2404 | s390_function_arg_float (struct type *type) |
| 2405 | { |
| 2406 | unsigned length = TYPE_LENGTH (type); |
| 2407 | if (length > 8) |
| 2408 | return 0; |
| 2409 | |
| 2410 | return is_float_like (type); |
| 2411 | } |
| 2412 | |
| 2413 | /* Return non-zero if TYPE should be passed in an integer register |
| 2414 | (or a pair of integer registers) if possible. */ |
| 2415 | static int |
| 2416 | s390_function_arg_integer (struct type *type) |
| 2417 | { |
| 2418 | unsigned length = TYPE_LENGTH (type); |
| 2419 | if (length > 8) |
| 2420 | return 0; |
| 2421 | |
| 2422 | return is_integer_like (type) |
| 2423 | || is_pointer_like (type) |
| 2424 | || (is_struct_like (type) && is_power_of_two (length)); |
| 2425 | } |
| 2426 | |
| 2427 | /* Return ARG, a `SIMPLE_ARG', sign-extended or zero-extended to a full |
| 2428 | word as required for the ABI. */ |
| 2429 | static LONGEST |
| 2430 | extend_simple_arg (struct value *arg) |
| 2431 | { |
| 2432 | struct type *type = value_type (arg); |
| 2433 | |
| 2434 | /* Even structs get passed in the least significant bits of the |
| 2435 | register / memory word. It's not really right to extract them as |
| 2436 | an integer, but it does take care of the extension. */ |
| 2437 | if (TYPE_UNSIGNED (type)) |
| 2438 | return extract_unsigned_integer (value_contents (arg), |
| 2439 | TYPE_LENGTH (type)); |
| 2440 | else |
| 2441 | return extract_signed_integer (value_contents (arg), |
| 2442 | TYPE_LENGTH (type)); |
| 2443 | } |
| 2444 | |
| 2445 | |
| 2446 | /* Return the alignment required by TYPE. */ |
| 2447 | static int |
| 2448 | alignment_of (struct type *type) |
| 2449 | { |
| 2450 | int alignment; |
| 2451 | |
| 2452 | if (is_integer_like (type) |
| 2453 | || is_pointer_like (type) |
| 2454 | || TYPE_CODE (type) == TYPE_CODE_FLT) |
| 2455 | alignment = TYPE_LENGTH (type); |
| 2456 | else if (TYPE_CODE (type) == TYPE_CODE_STRUCT |
| 2457 | || TYPE_CODE (type) == TYPE_CODE_UNION) |
| 2458 | { |
| 2459 | int i; |
| 2460 | |
| 2461 | alignment = 1; |
| 2462 | for (i = 0; i < TYPE_NFIELDS (type); i++) |
| 2463 | { |
| 2464 | int field_alignment = alignment_of (TYPE_FIELD_TYPE (type, i)); |
| 2465 | |
| 2466 | if (field_alignment > alignment) |
| 2467 | alignment = field_alignment; |
| 2468 | } |
| 2469 | } |
| 2470 | else |
| 2471 | alignment = 1; |
| 2472 | |
| 2473 | /* Check that everything we ever return is a power of two. Lots of |
| 2474 | code doesn't want to deal with aligning things to arbitrary |
| 2475 | boundaries. */ |
| 2476 | gdb_assert ((alignment & (alignment - 1)) == 0); |
| 2477 | |
| 2478 | return alignment; |
| 2479 | } |
| 2480 | |
| 2481 | |
| 2482 | /* Put the actual parameter values pointed to by ARGS[0..NARGS-1] in |
| 2483 | place to be passed to a function, as specified by the "GNU/Linux |
| 2484 | for S/390 ELF Application Binary Interface Supplement". |
| 2485 | |
| 2486 | SP is the current stack pointer. We must put arguments, links, |
| 2487 | padding, etc. whereever they belong, and return the new stack |
| 2488 | pointer value. |
| 2489 | |
| 2490 | If STRUCT_RETURN is non-zero, then the function we're calling is |
| 2491 | going to return a structure by value; STRUCT_ADDR is the address of |
| 2492 | a block we've allocated for it on the stack. |
| 2493 | |
| 2494 | Our caller has taken care of any type promotions needed to satisfy |
| 2495 | prototypes or the old K&R argument-passing rules. */ |
| 2496 | static CORE_ADDR |
| 2497 | s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function, |
| 2498 | struct regcache *regcache, CORE_ADDR bp_addr, |
| 2499 | int nargs, struct value **args, CORE_ADDR sp, |
| 2500 | int struct_return, CORE_ADDR struct_addr) |
| 2501 | { |
| 2502 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 2503 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 2504 | ULONGEST orig_sp; |
| 2505 | int i; |
| 2506 | |
| 2507 | /* If the i'th argument is passed as a reference to a copy, then |
| 2508 | copy_addr[i] is the address of the copy we made. */ |
| 2509 | CORE_ADDR *copy_addr = alloca (nargs * sizeof (CORE_ADDR)); |
| 2510 | |
| 2511 | /* Build the reference-to-copy area. */ |
| 2512 | for (i = 0; i < nargs; i++) |
| 2513 | { |
| 2514 | struct value *arg = args[i]; |
| 2515 | struct type *type = value_type (arg); |
| 2516 | unsigned length = TYPE_LENGTH (type); |
| 2517 | |
| 2518 | if (s390_function_arg_pass_by_reference (type)) |
| 2519 | { |
| 2520 | sp -= length; |
| 2521 | sp = align_down (sp, alignment_of (type)); |
| 2522 | write_memory (sp, value_contents (arg), length); |
| 2523 | copy_addr[i] = sp; |
| 2524 | } |
| 2525 | } |
| 2526 | |
| 2527 | /* Reserve space for the parameter area. As a conservative |
| 2528 | simplification, we assume that everything will be passed on the |
| 2529 | stack. Since every argument larger than 8 bytes will be |
| 2530 | passed by reference, we use this simple upper bound. */ |
| 2531 | sp -= nargs * 8; |
| 2532 | |
| 2533 | /* After all that, make sure it's still aligned on an eight-byte |
| 2534 | boundary. */ |
| 2535 | sp = align_down (sp, 8); |
| 2536 | |
| 2537 | /* Finally, place the actual parameters, working from SP towards |
| 2538 | higher addresses. The code above is supposed to reserve enough |
| 2539 | space for this. */ |
| 2540 | { |
| 2541 | int fr = 0; |
| 2542 | int gr = 2; |
| 2543 | CORE_ADDR starg = sp; |
| 2544 | |
| 2545 | /* A struct is returned using general register 2. */ |
| 2546 | if (struct_return) |
| 2547 | { |
| 2548 | regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr, |
| 2549 | struct_addr); |
| 2550 | gr++; |
| 2551 | } |
| 2552 | |
| 2553 | for (i = 0; i < nargs; i++) |
| 2554 | { |
| 2555 | struct value *arg = args[i]; |
| 2556 | struct type *type = value_type (arg); |
| 2557 | unsigned length = TYPE_LENGTH (type); |
| 2558 | |
| 2559 | if (s390_function_arg_pass_by_reference (type)) |
| 2560 | { |
| 2561 | if (gr <= 6) |
| 2562 | { |
| 2563 | regcache_cooked_write_unsigned (regcache, S390_R0_REGNUM + gr, |
| 2564 | copy_addr[i]); |
| 2565 | gr++; |
| 2566 | } |
| 2567 | else |
| 2568 | { |
| 2569 | write_memory_unsigned_integer (starg, word_size, copy_addr[i]); |
| 2570 | starg += word_size; |
| 2571 | } |
| 2572 | } |
| 2573 | else if (s390_function_arg_float (type)) |
| 2574 | { |
| 2575 | /* The GNU/Linux for S/390 ABI uses FPRs 0 and 2 to pass arguments, |
| 2576 | the GNU/Linux for zSeries ABI uses 0, 2, 4, and 6. */ |
| 2577 | if (fr <= (tdep->abi == ABI_LINUX_S390 ? 2 : 6)) |
| 2578 | { |
| 2579 | /* When we store a single-precision value in an FP register, |
| 2580 | it occupies the leftmost bits. */ |
| 2581 | regcache_cooked_write_part (regcache, S390_F0_REGNUM + fr, |
| 2582 | 0, length, value_contents (arg)); |
| 2583 | fr += 2; |
| 2584 | } |
| 2585 | else |
| 2586 | { |
| 2587 | /* When we store a single-precision value in a stack slot, |
| 2588 | it occupies the rightmost bits. */ |
| 2589 | starg = align_up (starg + length, word_size); |
| 2590 | write_memory (starg - length, value_contents (arg), length); |
| 2591 | } |
| 2592 | } |
| 2593 | else if (s390_function_arg_integer (type) && length <= word_size) |
| 2594 | { |
| 2595 | if (gr <= 6) |
| 2596 | { |
| 2597 | /* Integer arguments are always extended to word size. */ |
| 2598 | regcache_cooked_write_signed (regcache, S390_R0_REGNUM + gr, |
| 2599 | extend_simple_arg (arg)); |
| 2600 | gr++; |
| 2601 | } |
| 2602 | else |
| 2603 | { |
| 2604 | /* Integer arguments are always extended to word size. */ |
| 2605 | write_memory_signed_integer (starg, word_size, |
| 2606 | extend_simple_arg (arg)); |
| 2607 | starg += word_size; |
| 2608 | } |
| 2609 | } |
| 2610 | else if (s390_function_arg_integer (type) && length == 2*word_size) |
| 2611 | { |
| 2612 | if (gr <= 5) |
| 2613 | { |
| 2614 | regcache_cooked_write (regcache, S390_R0_REGNUM + gr, |
| 2615 | value_contents (arg)); |
| 2616 | regcache_cooked_write (regcache, S390_R0_REGNUM + gr + 1, |
| 2617 | value_contents (arg) + word_size); |
| 2618 | gr += 2; |
| 2619 | } |
| 2620 | else |
| 2621 | { |
| 2622 | /* If we skipped r6 because we couldn't fit a DOUBLE_ARG |
| 2623 | in it, then don't go back and use it again later. */ |
| 2624 | gr = 7; |
| 2625 | |
| 2626 | write_memory (starg, value_contents (arg), length); |
| 2627 | starg += length; |
| 2628 | } |
| 2629 | } |
| 2630 | else |
| 2631 | internal_error (__FILE__, __LINE__, _("unknown argument type")); |
| 2632 | } |
| 2633 | } |
| 2634 | |
| 2635 | /* Allocate the standard frame areas: the register save area, the |
| 2636 | word reserved for the compiler (which seems kind of meaningless), |
| 2637 | and the back chain pointer. */ |
| 2638 | sp -= 16*word_size + 32; |
| 2639 | |
| 2640 | /* Store return address. */ |
| 2641 | regcache_cooked_write_unsigned (regcache, S390_RETADDR_REGNUM, bp_addr); |
| 2642 | |
| 2643 | /* Store updated stack pointer. */ |
| 2644 | regcache_cooked_write_unsigned (regcache, S390_SP_REGNUM, sp); |
| 2645 | |
| 2646 | /* We need to return the 'stack part' of the frame ID, |
| 2647 | which is actually the top of the register save area. */ |
| 2648 | return sp + 16*word_size + 32; |
| 2649 | } |
| 2650 | |
| 2651 | /* Assuming NEXT_FRAME->prev is a dummy, return the frame ID of that |
| 2652 | dummy frame. The frame ID's base needs to match the TOS value |
| 2653 | returned by push_dummy_call, and the PC match the dummy frame's |
| 2654 | breakpoint. */ |
| 2655 | static struct frame_id |
| 2656 | s390_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 2657 | { |
| 2658 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 2659 | CORE_ADDR sp = s390_unwind_sp (gdbarch, next_frame); |
| 2660 | |
| 2661 | return frame_id_build (sp + 16*word_size + 32, |
| 2662 | frame_pc_unwind (next_frame)); |
| 2663 | } |
| 2664 | |
| 2665 | static CORE_ADDR |
| 2666 | s390_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr) |
| 2667 | { |
| 2668 | /* Both the 32- and 64-bit ABI's say that the stack pointer should |
| 2669 | always be aligned on an eight-byte boundary. */ |
| 2670 | return (addr & -8); |
| 2671 | } |
| 2672 | |
| 2673 | |
| 2674 | /* Function return value access. */ |
| 2675 | |
| 2676 | static enum return_value_convention |
| 2677 | s390_return_value_convention (struct gdbarch *gdbarch, struct type *type) |
| 2678 | { |
| 2679 | int length = TYPE_LENGTH (type); |
| 2680 | if (length > 8) |
| 2681 | return RETURN_VALUE_STRUCT_CONVENTION; |
| 2682 | |
| 2683 | switch (TYPE_CODE (type)) |
| 2684 | { |
| 2685 | case TYPE_CODE_STRUCT: |
| 2686 | case TYPE_CODE_UNION: |
| 2687 | case TYPE_CODE_ARRAY: |
| 2688 | return RETURN_VALUE_STRUCT_CONVENTION; |
| 2689 | |
| 2690 | default: |
| 2691 | return RETURN_VALUE_REGISTER_CONVENTION; |
| 2692 | } |
| 2693 | } |
| 2694 | |
| 2695 | static enum return_value_convention |
| 2696 | s390_return_value (struct gdbarch *gdbarch, struct type *type, |
| 2697 | struct regcache *regcache, void *out, const void *in) |
| 2698 | { |
| 2699 | int word_size = gdbarch_ptr_bit (gdbarch) / 8; |
| 2700 | int length = TYPE_LENGTH (type); |
| 2701 | enum return_value_convention rvc = |
| 2702 | s390_return_value_convention (gdbarch, type); |
| 2703 | if (in) |
| 2704 | { |
| 2705 | switch (rvc) |
| 2706 | { |
| 2707 | case RETURN_VALUE_REGISTER_CONVENTION: |
| 2708 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 2709 | { |
| 2710 | /* When we store a single-precision value in an FP register, |
| 2711 | it occupies the leftmost bits. */ |
| 2712 | regcache_cooked_write_part (regcache, S390_F0_REGNUM, |
| 2713 | 0, length, in); |
| 2714 | } |
| 2715 | else if (length <= word_size) |
| 2716 | { |
| 2717 | /* Integer arguments are always extended to word size. */ |
| 2718 | if (TYPE_UNSIGNED (type)) |
| 2719 | regcache_cooked_write_unsigned (regcache, S390_R2_REGNUM, |
| 2720 | extract_unsigned_integer (in, length)); |
| 2721 | else |
| 2722 | regcache_cooked_write_signed (regcache, S390_R2_REGNUM, |
| 2723 | extract_signed_integer (in, length)); |
| 2724 | } |
| 2725 | else if (length == 2*word_size) |
| 2726 | { |
| 2727 | regcache_cooked_write (regcache, S390_R2_REGNUM, in); |
| 2728 | regcache_cooked_write (regcache, S390_R3_REGNUM, |
| 2729 | (const char *)in + word_size); |
| 2730 | } |
| 2731 | else |
| 2732 | internal_error (__FILE__, __LINE__, _("invalid return type")); |
| 2733 | break; |
| 2734 | |
| 2735 | case RETURN_VALUE_STRUCT_CONVENTION: |
| 2736 | error (_("Cannot set function return value.")); |
| 2737 | break; |
| 2738 | } |
| 2739 | } |
| 2740 | else if (out) |
| 2741 | { |
| 2742 | switch (rvc) |
| 2743 | { |
| 2744 | case RETURN_VALUE_REGISTER_CONVENTION: |
| 2745 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 2746 | { |
| 2747 | /* When we store a single-precision value in an FP register, |
| 2748 | it occupies the leftmost bits. */ |
| 2749 | regcache_cooked_read_part (regcache, S390_F0_REGNUM, |
| 2750 | 0, length, out); |
| 2751 | } |
| 2752 | else if (length <= word_size) |
| 2753 | { |
| 2754 | /* Integer arguments occupy the rightmost bits. */ |
| 2755 | regcache_cooked_read_part (regcache, S390_R2_REGNUM, |
| 2756 | word_size - length, length, out); |
| 2757 | } |
| 2758 | else if (length == 2*word_size) |
| 2759 | { |
| 2760 | regcache_cooked_read (regcache, S390_R2_REGNUM, out); |
| 2761 | regcache_cooked_read (regcache, S390_R3_REGNUM, |
| 2762 | (char *)out + word_size); |
| 2763 | } |
| 2764 | else |
| 2765 | internal_error (__FILE__, __LINE__, _("invalid return type")); |
| 2766 | break; |
| 2767 | |
| 2768 | case RETURN_VALUE_STRUCT_CONVENTION: |
| 2769 | error (_("Function return value unknown.")); |
| 2770 | break; |
| 2771 | } |
| 2772 | } |
| 2773 | |
| 2774 | return rvc; |
| 2775 | } |
| 2776 | |
| 2777 | |
| 2778 | /* Breakpoints. */ |
| 2779 | |
| 2780 | static const unsigned char * |
| 2781 | s390_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr) |
| 2782 | { |
| 2783 | static unsigned char breakpoint[] = { 0x0, 0x1 }; |
| 2784 | |
| 2785 | *lenptr = sizeof (breakpoint); |
| 2786 | return breakpoint; |
| 2787 | } |
| 2788 | |
| 2789 | |
| 2790 | /* Address handling. */ |
| 2791 | |
| 2792 | static CORE_ADDR |
| 2793 | s390_addr_bits_remove (CORE_ADDR addr) |
| 2794 | { |
| 2795 | return addr & 0x7fffffff; |
| 2796 | } |
| 2797 | |
| 2798 | static int |
| 2799 | s390_address_class_type_flags (int byte_size, int dwarf2_addr_class) |
| 2800 | { |
| 2801 | if (byte_size == 4) |
| 2802 | return TYPE_FLAG_ADDRESS_CLASS_1; |
| 2803 | else |
| 2804 | return 0; |
| 2805 | } |
| 2806 | |
| 2807 | static const char * |
| 2808 | s390_address_class_type_flags_to_name (struct gdbarch *gdbarch, int type_flags) |
| 2809 | { |
| 2810 | if (type_flags & TYPE_FLAG_ADDRESS_CLASS_1) |
| 2811 | return "mode32"; |
| 2812 | else |
| 2813 | return NULL; |
| 2814 | } |
| 2815 | |
| 2816 | static int |
| 2817 | s390_address_class_name_to_type_flags (struct gdbarch *gdbarch, const char *name, |
| 2818 | int *type_flags_ptr) |
| 2819 | { |
| 2820 | if (strcmp (name, "mode32") == 0) |
| 2821 | { |
| 2822 | *type_flags_ptr = TYPE_FLAG_ADDRESS_CLASS_1; |
| 2823 | return 1; |
| 2824 | } |
| 2825 | else |
| 2826 | return 0; |
| 2827 | } |
| 2828 | |
| 2829 | |
| 2830 | /* Link map offsets. */ |
| 2831 | |
| 2832 | static struct link_map_offsets * |
| 2833 | s390_svr4_fetch_link_map_offsets (void) |
| 2834 | { |
| 2835 | static struct link_map_offsets lmo; |
| 2836 | static struct link_map_offsets *lmp = NULL; |
| 2837 | |
| 2838 | if (lmp == NULL) |
| 2839 | { |
| 2840 | lmp = &lmo; |
| 2841 | |
| 2842 | lmo.r_debug_size = 8; |
| 2843 | |
| 2844 | lmo.r_map_offset = 4; |
| 2845 | lmo.r_map_size = 4; |
| 2846 | |
| 2847 | lmo.link_map_size = 20; |
| 2848 | |
| 2849 | lmo.l_addr_offset = 0; |
| 2850 | lmo.l_addr_size = 4; |
| 2851 | |
| 2852 | lmo.l_name_offset = 4; |
| 2853 | lmo.l_name_size = 4; |
| 2854 | |
| 2855 | lmo.l_next_offset = 12; |
| 2856 | lmo.l_next_size = 4; |
| 2857 | |
| 2858 | lmo.l_prev_offset = 16; |
| 2859 | lmo.l_prev_size = 4; |
| 2860 | } |
| 2861 | |
| 2862 | return lmp; |
| 2863 | } |
| 2864 | |
| 2865 | static struct link_map_offsets * |
| 2866 | s390x_svr4_fetch_link_map_offsets (void) |
| 2867 | { |
| 2868 | static struct link_map_offsets lmo; |
| 2869 | static struct link_map_offsets *lmp = NULL; |
| 2870 | |
| 2871 | if (lmp == NULL) |
| 2872 | { |
| 2873 | lmp = &lmo; |
| 2874 | |
| 2875 | lmo.r_debug_size = 16; /* All we need. */ |
| 2876 | |
| 2877 | lmo.r_map_offset = 8; |
| 2878 | lmo.r_map_size = 8; |
| 2879 | |
| 2880 | lmo.link_map_size = 40; /* All we need. */ |
| 2881 | |
| 2882 | lmo.l_addr_offset = 0; |
| 2883 | lmo.l_addr_size = 8; |
| 2884 | |
| 2885 | lmo.l_name_offset = 8; |
| 2886 | lmo.l_name_size = 8; |
| 2887 | |
| 2888 | lmo.l_next_offset = 24; |
| 2889 | lmo.l_next_size = 8; |
| 2890 | |
| 2891 | lmo.l_prev_offset = 32; |
| 2892 | lmo.l_prev_size = 8; |
| 2893 | } |
| 2894 | |
| 2895 | return lmp; |
| 2896 | } |
| 2897 | |
| 2898 | |
| 2899 | /* Set up gdbarch struct. */ |
| 2900 | |
| 2901 | static struct gdbarch * |
| 2902 | s390_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| 2903 | { |
| 2904 | struct gdbarch *gdbarch; |
| 2905 | struct gdbarch_tdep *tdep; |
| 2906 | |
| 2907 | /* First see if there is already a gdbarch that can satisfy the request. */ |
| 2908 | arches = gdbarch_list_lookup_by_info (arches, &info); |
| 2909 | if (arches != NULL) |
| 2910 | return arches->gdbarch; |
| 2911 | |
| 2912 | /* None found: is the request for a s390 architecture? */ |
| 2913 | if (info.bfd_arch_info->arch != bfd_arch_s390) |
| 2914 | return NULL; /* No; then it's not for us. */ |
| 2915 | |
| 2916 | /* Yes: create a new gdbarch for the specified machine type. */ |
| 2917 | tdep = XCALLOC (1, struct gdbarch_tdep); |
| 2918 | gdbarch = gdbarch_alloc (&info, tdep); |
| 2919 | |
| 2920 | set_gdbarch_believe_pcc_promotion (gdbarch, 0); |
| 2921 | set_gdbarch_char_signed (gdbarch, 0); |
| 2922 | |
| 2923 | /* Amount PC must be decremented by after a breakpoint. This is |
| 2924 | often the number of bytes returned by BREAKPOINT_FROM_PC but not |
| 2925 | always. */ |
| 2926 | set_gdbarch_decr_pc_after_break (gdbarch, 2); |
| 2927 | /* Stack grows downward. */ |
| 2928 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| 2929 | set_gdbarch_breakpoint_from_pc (gdbarch, s390_breakpoint_from_pc); |
| 2930 | set_gdbarch_skip_prologue (gdbarch, s390_skip_prologue); |
| 2931 | set_gdbarch_in_function_epilogue_p (gdbarch, s390_in_function_epilogue_p); |
| 2932 | |
| 2933 | set_gdbarch_pc_regnum (gdbarch, S390_PC_REGNUM); |
| 2934 | set_gdbarch_sp_regnum (gdbarch, S390_SP_REGNUM); |
| 2935 | set_gdbarch_fp0_regnum (gdbarch, S390_F0_REGNUM); |
| 2936 | set_gdbarch_num_regs (gdbarch, S390_NUM_REGS); |
| 2937 | set_gdbarch_num_pseudo_regs (gdbarch, S390_NUM_PSEUDO_REGS); |
| 2938 | set_gdbarch_register_name (gdbarch, s390_register_name); |
| 2939 | set_gdbarch_register_type (gdbarch, s390_register_type); |
| 2940 | set_gdbarch_stab_reg_to_regnum (gdbarch, s390_dwarf_reg_to_regnum); |
| 2941 | set_gdbarch_dwarf_reg_to_regnum (gdbarch, s390_dwarf_reg_to_regnum); |
| 2942 | set_gdbarch_dwarf2_reg_to_regnum (gdbarch, s390_dwarf_reg_to_regnum); |
| 2943 | set_gdbarch_convert_register_p (gdbarch, s390_convert_register_p); |
| 2944 | set_gdbarch_register_to_value (gdbarch, s390_register_to_value); |
| 2945 | set_gdbarch_value_to_register (gdbarch, s390_value_to_register); |
| 2946 | set_gdbarch_register_reggroup_p (gdbarch, s390_register_reggroup_p); |
| 2947 | set_gdbarch_regset_from_core_section (gdbarch, |
| 2948 | s390_regset_from_core_section); |
| 2949 | |
| 2950 | /* Inferior function calls. */ |
| 2951 | set_gdbarch_push_dummy_call (gdbarch, s390_push_dummy_call); |
| 2952 | set_gdbarch_unwind_dummy_id (gdbarch, s390_unwind_dummy_id); |
| 2953 | set_gdbarch_frame_align (gdbarch, s390_frame_align); |
| 2954 | set_gdbarch_return_value (gdbarch, s390_return_value); |
| 2955 | |
| 2956 | /* Frame handling. */ |
| 2957 | dwarf2_frame_set_init_reg (gdbarch, s390_dwarf2_frame_init_reg); |
| 2958 | frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer); |
| 2959 | frame_base_append_sniffer (gdbarch, dwarf2_frame_base_sniffer); |
| 2960 | frame_unwind_append_sniffer (gdbarch, s390_stub_frame_sniffer); |
| 2961 | frame_unwind_append_sniffer (gdbarch, s390_sigtramp_frame_sniffer); |
| 2962 | frame_unwind_append_sniffer (gdbarch, s390_frame_sniffer); |
| 2963 | frame_base_set_default (gdbarch, &s390_frame_base); |
| 2964 | set_gdbarch_unwind_pc (gdbarch, s390_unwind_pc); |
| 2965 | set_gdbarch_unwind_sp (gdbarch, s390_unwind_sp); |
| 2966 | |
| 2967 | switch (info.bfd_arch_info->mach) |
| 2968 | { |
| 2969 | case bfd_mach_s390_31: |
| 2970 | tdep->abi = ABI_LINUX_S390; |
| 2971 | |
| 2972 | tdep->gregset = &s390_gregset; |
| 2973 | tdep->sizeof_gregset = s390_sizeof_gregset; |
| 2974 | tdep->fpregset = &s390_fpregset; |
| 2975 | tdep->sizeof_fpregset = s390_sizeof_fpregset; |
| 2976 | |
| 2977 | set_gdbarch_addr_bits_remove (gdbarch, s390_addr_bits_remove); |
| 2978 | set_gdbarch_pseudo_register_read (gdbarch, s390_pseudo_register_read); |
| 2979 | set_gdbarch_pseudo_register_write (gdbarch, s390_pseudo_register_write); |
| 2980 | set_solib_svr4_fetch_link_map_offsets (gdbarch, |
| 2981 | s390_svr4_fetch_link_map_offsets); |
| 2982 | |
| 2983 | break; |
| 2984 | case bfd_mach_s390_64: |
| 2985 | tdep->abi = ABI_LINUX_ZSERIES; |
| 2986 | |
| 2987 | tdep->gregset = &s390x_gregset; |
| 2988 | tdep->sizeof_gregset = s390x_sizeof_gregset; |
| 2989 | tdep->fpregset = &s390_fpregset; |
| 2990 | tdep->sizeof_fpregset = s390_sizeof_fpregset; |
| 2991 | |
| 2992 | set_gdbarch_long_bit (gdbarch, 64); |
| 2993 | set_gdbarch_long_long_bit (gdbarch, 64); |
| 2994 | set_gdbarch_ptr_bit (gdbarch, 64); |
| 2995 | set_gdbarch_pseudo_register_read (gdbarch, s390x_pseudo_register_read); |
| 2996 | set_gdbarch_pseudo_register_write (gdbarch, s390x_pseudo_register_write); |
| 2997 | set_solib_svr4_fetch_link_map_offsets (gdbarch, |
| 2998 | s390x_svr4_fetch_link_map_offsets); |
| 2999 | set_gdbarch_address_class_type_flags (gdbarch, |
| 3000 | s390_address_class_type_flags); |
| 3001 | set_gdbarch_address_class_type_flags_to_name (gdbarch, |
| 3002 | s390_address_class_type_flags_to_name); |
| 3003 | set_gdbarch_address_class_name_to_type_flags (gdbarch, |
| 3004 | s390_address_class_name_to_type_flags); |
| 3005 | break; |
| 3006 | } |
| 3007 | |
| 3008 | set_gdbarch_print_insn (gdbarch, print_insn_s390); |
| 3009 | |
| 3010 | return gdbarch; |
| 3011 | } |
| 3012 | |
| 3013 | |
| 3014 | |
| 3015 | extern initialize_file_ftype _initialize_s390_tdep; /* -Wmissing-prototypes */ |
| 3016 | |
| 3017 | void |
| 3018 | _initialize_s390_tdep (void) |
| 3019 | { |
| 3020 | |
| 3021 | /* Hook us into the gdbarch mechanism. */ |
| 3022 | register_gdbarch_init (bfd_arch_s390, s390_gdbarch_init); |
| 3023 | } |