gdb/sparc64-linux-tdep.c

   1 /* Target-dependent code for GNU/Linux UltraSPARC.
   2
   3    Copyright (C) 2003-2017 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "frame.h"
  22 #include "frame-unwind.h"
  23 #include "dwarf2-frame.h"
  24 #include "regset.h"
  25 #include "regcache.h"
  26 #include "gdbarch.h"
  27 #include "gdbcore.h"
  28 #include "osabi.h"
  29 #include "solib-svr4.h"
  30 #include "symtab.h"
  31 #include "trad-frame.h"
  32 #include "tramp-frame.h"
  33 #include "xml-syscall.h"
  34 #include "linux-tdep.h"
  35
  36 /* ADI specific si_code */
  37 #ifndef SEGV_ACCADI
  38 #define SEGV_ACCADI     3
  39 #endif
  40 #ifndef SEGV_ADIDERR
  41 #define SEGV_ADIDERR    4
  42 #endif
  43 #ifndef SEGV_ADIPERR
  44 #define SEGV_ADIPERR    5
  45 #endif
  46
  47 /* The syscall's XML filename for sparc 64-bit.  */
  48 #define XML_SYSCALL_FILENAME_SPARC64 "syscalls/sparc64-linux.xml"
  49
  50 #include "sparc64-tdep.h"
  51
  52 /* Signal trampoline support.  */
  53
  54 static void sparc64_linux_sigframe_init (const struct tramp_frame *self,
  55                                          struct frame_info *this_frame,
  56                                          struct trad_frame_cache *this_cache,
  57                                          CORE_ADDR func);
  58
  59 /* See sparc-linux-tdep.c for details.  Note that 64-bit binaries only
  60    use RT signals.  */
  61
  62 static const struct tramp_frame sparc64_linux_rt_sigframe =
  63 {
  64   SIGTRAMP_FRAME,
  65   4,
  66   {
  67     { 0x82102065, -1 },         /* mov __NR_rt_sigreturn, %g1 */
  68     { 0x91d0206d, -1 },         /* ta  0x6d */
  69     { TRAMP_SENTINEL_INSN, -1 }
  70   },
  71   sparc64_linux_sigframe_init
  72 };
  73
  74 static void
  75 sparc64_linux_sigframe_init (const struct tramp_frame *self,
  76                              struct frame_info *this_frame,
  77                              struct trad_frame_cache *this_cache,
  78                              CORE_ADDR func)
  79 {
  80   CORE_ADDR base, addr, sp_addr;
  81   int regnum;
  82
  83   base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM);
  84   base += 128;
  85
  86   /* Offsets from <bits/sigcontext.h>.  */
  87
  88   /* Since %g0 is always zero, keep the identity encoding.  */
  89   addr = base + 8;
  90   sp_addr = base + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 8);
  91   for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
  92     {
  93       trad_frame_set_reg_addr (this_cache, regnum, addr);
  94       addr += 8;
  95     }
  96
  97   trad_frame_set_reg_addr (this_cache, SPARC64_STATE_REGNUM, addr + 0);
  98   trad_frame_set_reg_addr (this_cache, SPARC64_PC_REGNUM, addr + 8);
  99   trad_frame_set_reg_addr (this_cache, SPARC64_NPC_REGNUM, addr + 16);
 100   trad_frame_set_reg_addr (this_cache, SPARC64_Y_REGNUM, addr + 24);
 101   trad_frame_set_reg_addr (this_cache, SPARC64_FPRS_REGNUM, addr + 28);
 102
 103   base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
 104   if (base & 1)
 105     base += BIAS;
 106
 107   addr = get_frame_memory_unsigned (this_frame, sp_addr, 8);
 108   if (addr & 1)
 109     addr += BIAS;
 110
 111   for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
 112     {
 113       trad_frame_set_reg_addr (this_cache, regnum, addr);
 114       addr += 8;
 115     }
 116   trad_frame_set_id (this_cache, frame_id_build (base, func));
 117 }
 118
 119 /* sparc64 GNU/Linux implementation of the handle_segmentation_fault
 120    gdbarch hook.
 121    Displays information related to ADI memory corruptions.  */
 122
 123 void
 124 sparc64_linux_handle_segmentation_fault (struct gdbarch *gdbarch,
 125                                       struct ui_out *uiout)
 126 {
 127   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word != 64)
 128     return;
 129
 130   CORE_ADDR addr = 0;
 131   long si_code = 0;
 132
 133   TRY
 134     {
 135       /* Evaluate si_code to see if the segfault is ADI related.  */
 136       si_code = parse_and_eval_long ("$_siginfo.si_code\n");
 137
 138       if (si_code >= SEGV_ACCADI && si_code <= SEGV_ADIPERR)
 139         addr = parse_and_eval_long ("$_siginfo._sifields._sigfault.si_addr");
 140     }
 141   CATCH (exception, RETURN_MASK_ALL)
 142     {
 143       return;
 144     }
 145   END_CATCH
 146
 147   /* Print out ADI event based on sig_code value */
 148   switch (si_code)
 149     {
 150     case SEGV_ACCADI:   /* adi not enabled */
 151       uiout->text ("\n");
 152       uiout->field_string ("sigcode-meaning", _("ADI disabled"));
 153       uiout->text (_(" while accessing address "));
 154       uiout->field_fmt ("bound-access", "%s", paddress (gdbarch, addr));
 155       break;
 156     case SEGV_ADIDERR:  /* disrupting mismatch */
 157       uiout->text ("\n");
 158       uiout->field_string ("sigcode-meaning", _("ADI deferred mismatch"));
 159       uiout->text (_(" while accessing address "));
 160       uiout->field_fmt ("bound-access", "%s", paddress (gdbarch, addr));
 161       break;
 162     case SEGV_ADIPERR:  /* precise mismatch */
 163       uiout->text ("\n");
 164       uiout->field_string ("sigcode-meaning", _("ADI precise mismatch"));
 165       uiout->text (_(" while accessing address "));
 166       uiout->field_fmt ("bound-access", "%s", paddress (gdbarch, addr));
 167       break;
 168     default:
 169       break;
 170     }
 171
 172 }
 173
 174 \f
 175 /* Return the address of a system call's alternative return
 176    address.  */
 177
 178 static CORE_ADDR
 179 sparc64_linux_step_trap (struct frame_info *frame, unsigned long insn)
 180 {
 181   /* __NR_rt_sigreturn is 101  */
 182   if ((insn == 0x91d0206d)
 183       && (get_frame_register_unsigned (frame, SPARC_G1_REGNUM) == 101))
 184     {
 185       struct gdbarch *gdbarch = get_frame_arch (frame);
 186       enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 187
 188       ULONGEST sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);
 189       if (sp & 1)
 190         sp += BIAS;
 191
 192       /* The kernel puts the sigreturn registers on the stack,
 193          and this is where the signal unwinding state is take from
 194          when returning from a signal.
 195
 196          A siginfo_t sits 192 bytes from the base of the stack.  This
 197          siginfo_t is 128 bytes, and is followed by the sigreturn
 198          register save area.  The saved PC sits at a 136 byte offset
 199          into there.  */
 200
 201       return read_memory_unsigned_integer (sp + 192 + 128 + 136,
 202                                            8, byte_order);
 203     }
 204
 205   return 0;
 206 }
 207 \f
 208
 209 const struct sparc_gregmap sparc64_linux_core_gregmap =
 210 {
 211   32 * 8,                       /* %tstate */
 212   33 * 8,                       /* %tpc */
 213   34 * 8,                       /* %tnpc */
 214   35 * 8,                       /* %y */
 215   -1,                           /* %wim */
 216   -1,                           /* %tbr */
 217   1 * 8,                        /* %g1 */
 218   16 * 8,                       /* %l0 */
 219   8,                            /* y size */
 220 };
 221 \f
 222
 223 static void
 224 sparc64_linux_supply_core_gregset (const struct regset *regset,
 225                                    struct regcache *regcache,
 226                                    int regnum, const void *gregs, size_t len)
 227 {
 228   sparc64_supply_gregset (&sparc64_linux_core_gregmap,
 229                           regcache, regnum, gregs);
 230 }
 231
 232 static void
 233 sparc64_linux_collect_core_gregset (const struct regset *regset,
 234                                     const struct regcache *regcache,
 235                                     int regnum, void *gregs, size_t len)
 236 {
 237   sparc64_collect_gregset (&sparc64_linux_core_gregmap,
 238                            regcache, regnum, gregs);
 239 }
 240
 241 static void
 242 sparc64_linux_supply_core_fpregset (const struct regset *regset,
 243                                     struct regcache *regcache,
 244                                     int regnum, const void *fpregs, size_t len)
 245 {
 246   sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs);
 247 }
 248
 249 static void
 250 sparc64_linux_collect_core_fpregset (const struct regset *regset,
 251                                      const struct regcache *regcache,
 252                                      int regnum, void *fpregs, size_t len)
 253 {
 254   sparc64_collect_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs);
 255 }
 256
 257 /* Set the program counter for process PTID to PC.  */
 258
 259 #define TSTATE_SYSCALL  0x0000000000000020ULL
 260
 261 static void
 262 sparc64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
 263 {
 264   struct gdbarch_tdep *tdep = gdbarch_tdep (regcache->arch ());
 265   ULONGEST state;
 266
 267   regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
 268   regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);
 269
 270   /* Clear the "in syscall" bit to prevent the kernel from
 271      messing with the PCs we just installed, if we happen to be
 272      within an interrupted system call that the kernel wants to
 273      restart.
 274
 275      Note that after we return from the dummy call, the TSTATE et al.
 276      registers will be automatically restored, and the kernel
 277      continues to restart the system call at this point.  */
 278   regcache_cooked_read_unsigned (regcache, SPARC64_STATE_REGNUM, &state);
 279   state &= ~TSTATE_SYSCALL;
 280   regcache_cooked_write_unsigned (regcache, SPARC64_STATE_REGNUM, state);
 281 }
 282
 283 static LONGEST
 284 sparc64_linux_get_syscall_number (struct gdbarch *gdbarch,
 285                                   ptid_t ptid)
 286 {
 287   struct regcache *regcache = get_thread_regcache (ptid);
 288   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 289   /* The content of a register.  */
 290   gdb_byte buf[8];
 291   /* The result.  */
 292   LONGEST ret;
 293
 294   /* Getting the system call number from the register.
 295      When dealing with the sparc architecture, this information
 296      is stored at the %g1 register.  */
 297   regcache_cooked_read (regcache, SPARC_G1_REGNUM, buf);
 298
 299   ret = extract_signed_integer (buf, 8, byte_order);
 300
 301   return ret;
 302 }
 303
 304 \f
 305 /* Implement the "get_longjmp_target" gdbarch method.  */
 306
 307 static int
 308 sparc64_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
 309 {
 310   struct gdbarch *gdbarch = get_frame_arch (frame);
 311   CORE_ADDR jb_addr;
 312   gdb_byte buf[8];
 313
 314   jb_addr = get_frame_register_unsigned (frame, SPARC_O0_REGNUM);
 315
 316   /* setjmp and longjmp in SPARC64 are implemented in glibc using the
 317      setcontext and getcontext system calls respectively.  These
 318      system calls operate on ucontext_t structures, which happen to
 319      partially have the same structure than jmp_buf.  However the
 320      ucontext returned by getcontext, and thus the jmp_buf structure
 321      returned by setjmp, contains the context of the trap instruction
 322      in the glibc __[sig]setjmp wrapper, not the context of the user
 323      code calling setjmp.
 324
 325      %o7 in the jmp_buf structure is stored at offset 18*8 in the
 326      mc_gregs array, which is itself located at offset 32 into
 327      jmp_buf.  See bits/setjmp.h.  This register contains the address
 328      of the 'call setjmp' instruction in user code.
 329
 330      In order to determine the longjmp target address in the
 331      initiating frame we need to examine the call instruction itself,
 332      in particular whether the annul bit is set.  If it is not set
 333      then we need to jump over the instruction at the delay slot.  */
 334
 335   if (target_read_memory (jb_addr + 32 + (18 * 8), buf, 8))
 336     return 0;
 337
 338   *pc = extract_unsigned_integer (buf, 8, gdbarch_byte_order (gdbarch));
 339
 340   if (!sparc_is_annulled_branch_insn (*pc))
 341       *pc += 4; /* delay slot insn  */
 342   *pc += 4; /* call insn  */
 343
 344   return 1;
 345 }
 346
 347 \f
 348
 349 static const struct regset sparc64_linux_gregset =
 350   {
 351     NULL,
 352     sparc64_linux_supply_core_gregset,
 353     sparc64_linux_collect_core_gregset
 354   };
 355
 356 static const struct regset sparc64_linux_fpregset =
 357   {
 358     NULL,
 359     sparc64_linux_supply_core_fpregset,
 360     sparc64_linux_collect_core_fpregset
 361   };
 362
 363 static void
 364 sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 365 {
 366   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 367
 368   linux_init_abi (info, gdbarch);
 369
 370   tdep->gregset = &sparc64_linux_gregset;
 371   tdep->sizeof_gregset = 288;
 372
 373   tdep->fpregset = &sparc64_linux_fpregset;
 374   tdep->sizeof_fpregset = 280;
 375
 376   tramp_frame_prepend_unwinder (gdbarch, &sparc64_linux_rt_sigframe);
 377
 378   /* Hook in the DWARF CFI frame unwinder.  */
 379   dwarf2_append_unwinders (gdbarch);
 380
 381   sparc64_init_abi (info, gdbarch);
 382
 383   /* GNU/Linux has SVR4-style shared libraries...  */
 384   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 385   set_solib_svr4_fetch_link_map_offsets
 386     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 387
 388   /* ...which means that we need some special handling when doing
 389      prologue analysis.  */
 390   tdep->plt_entry_size = 16;
 391
 392   /* Enable TLS support.  */
 393   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 394                                              svr4_fetch_objfile_link_map);
 395
 396   /* Make sure we can single-step over signal return system calls.  */
 397   tdep->step_trap = sparc64_linux_step_trap;
 398
 399   /* Make sure we can single-step over longjmp calls.  */
 400   set_gdbarch_get_longjmp_target (gdbarch, sparc64_linux_get_longjmp_target);
 401
 402   set_gdbarch_write_pc (gdbarch, sparc64_linux_write_pc);
 403
 404   /* Functions for 'catch syscall'.  */
 405   set_xml_syscall_file_name (gdbarch, XML_SYSCALL_FILENAME_SPARC64);
 406   set_gdbarch_get_syscall_number (gdbarch,
 407                                   sparc64_linux_get_syscall_number);
 408   set_gdbarch_handle_segmentation_fault (gdbarch,
 409                                          sparc64_linux_handle_segmentation_fault);
 410 }
 411
 412 void
 413 _initialize_sparc64_linux_tdep (void)
 414 {
 415   gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
 416                           GDB_OSABI_LINUX, sparc64_linux_init_abi);
 417 }