gdb/sparc64-linux-tdep.c

   1 /* Target-dependent code for GNU/Linux UltraSPARC.
   2
   3    Copyright (C) 2003-2013 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 /* The syscall's XML filename for sparc 64-bit.  */
  37 #define XML_SYSCALL_FILENAME_SPARC64 "syscalls/sparc64-linux.xml"
  38
  39 #include "sparc64-tdep.h"
  40
  41 /* Signal trampoline support.  */
  42
  43 static void sparc64_linux_sigframe_init (const struct tramp_frame *self,
  44                                          struct frame_info *this_frame,
  45                                          struct trad_frame_cache *this_cache,
  46                                          CORE_ADDR func);
  47
  48 /* See sparc-linux-tdep.c for details.  Note that 64-bit binaries only
  49    use RT signals.  */
  50
  51 static const struct tramp_frame sparc64_linux_rt_sigframe =
  52 {
  53   SIGTRAMP_FRAME,
  54   4,
  55   {
  56     { 0x82102065, -1 },         /* mov __NR_rt_sigreturn, %g1 */
  57     { 0x91d0206d, -1 },         /* ta  0x6d */
  58     { TRAMP_SENTINEL_INSN, -1 }
  59   },
  60   sparc64_linux_sigframe_init
  61 };
  62
  63 static void
  64 sparc64_linux_sigframe_init (const struct tramp_frame *self,
  65                              struct frame_info *this_frame,
  66                              struct trad_frame_cache *this_cache,
  67                              CORE_ADDR func)
  68 {
  69   CORE_ADDR base, addr, sp_addr;
  70   int regnum;
  71
  72   base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM);
  73   base += 128;
  74
  75   /* Offsets from <bits/sigcontext.h>.  */
  76
  77   /* Since %g0 is always zero, keep the identity encoding.  */
  78   addr = base + 8;
  79   sp_addr = base + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 8);
  80   for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
  81     {
  82       trad_frame_set_reg_addr (this_cache, regnum, addr);
  83       addr += 8;
  84     }
  85
  86   trad_frame_set_reg_addr (this_cache, SPARC64_STATE_REGNUM, addr + 0);
  87   trad_frame_set_reg_addr (this_cache, SPARC64_PC_REGNUM, addr + 8);
  88   trad_frame_set_reg_addr (this_cache, SPARC64_NPC_REGNUM, addr + 16);
  89   trad_frame_set_reg_addr (this_cache, SPARC64_Y_REGNUM, addr + 24);
  90   trad_frame_set_reg_addr (this_cache, SPARC64_FPRS_REGNUM, addr + 28);
  91
  92   base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
  93   if (base & 1)
  94     base += BIAS;
  95
  96   addr = get_frame_memory_unsigned (this_frame, sp_addr, 8);
  97   if (addr & 1)
  98     addr += BIAS;
  99
 100   for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
 101     {
 102       trad_frame_set_reg_addr (this_cache, regnum, addr);
 103       addr += 8;
 104     }
 105   trad_frame_set_id (this_cache, frame_id_build (base, func));
 106 }
 107 \f
 108 /* Return the address of a system call's alternative return
 109    address.  */
 110
 111 static CORE_ADDR
 112 sparc64_linux_step_trap (struct frame_info *frame, unsigned long insn)
 113 {
 114   if (insn == 0x91d0206d)
 115     {
 116       struct gdbarch *gdbarch = get_frame_arch (frame);
 117       enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 118
 119       ULONGEST sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);
 120       if (sp & 1)
 121         sp += BIAS;
 122
 123       /* The kernel puts the sigreturn registers on the stack,
 124          and this is where the signal unwinding state is take from
 125          when returning from a signal.
 126
 127          A siginfo_t sits 192 bytes from the base of the stack.  This
 128          siginfo_t is 128 bytes, and is followed by the sigreturn
 129          register save area.  The saved PC sits at a 136 byte offset
 130          into there.  */
 131
 132       return read_memory_unsigned_integer (sp + 192 + 128 + 136,
 133                                            8, byte_order);
 134     }
 135
 136   return 0;
 137 }
 138 \f
 139
 140 const struct sparc_gregset sparc64_linux_core_gregset =
 141 {
 142   32 * 8,                       /* %tstate */
 143   33 * 8,                       /* %tpc */
 144   34 * 8,                       /* %tnpc */
 145   35 * 8,                       /* %y */
 146   -1,                           /* %wim */
 147   -1,                           /* %tbr */
 148   1 * 8,                        /* %g1 */
 149   16 * 8,                       /* %l0 */
 150   8,                            /* y size */
 151 };
 152 \f
 153
 154 static void
 155 sparc64_linux_supply_core_gregset (const struct regset *regset,
 156                                    struct regcache *regcache,
 157                                    int regnum, const void *gregs, size_t len)
 158 {
 159   sparc64_supply_gregset (&sparc64_linux_core_gregset,
 160                           regcache, regnum, gregs);
 161 }
 162
 163 static void
 164 sparc64_linux_collect_core_gregset (const struct regset *regset,
 165                                     const struct regcache *regcache,
 166                                     int regnum, void *gregs, size_t len)
 167 {
 168   sparc64_collect_gregset (&sparc64_linux_core_gregset,
 169                            regcache, regnum, gregs);
 170 }
 171
 172 static void
 173 sparc64_linux_supply_core_fpregset (const struct regset *regset,
 174                                     struct regcache *regcache,
 175                                     int regnum, const void *fpregs, size_t len)
 176 {
 177   sparc64_supply_fpregset (&sparc64_bsd_fpregset, regcache, regnum, fpregs);
 178 }
 179
 180 static void
 181 sparc64_linux_collect_core_fpregset (const struct regset *regset,
 182                                      const struct regcache *regcache,
 183                                      int regnum, void *fpregs, size_t len)
 184 {
 185   sparc64_collect_fpregset (&sparc64_bsd_fpregset, regcache, regnum, fpregs);
 186 }
 187
 188 /* Set the program counter for process PTID to PC.  */
 189
 190 #define TSTATE_SYSCALL  0x0000000000000020ULL
 191
 192 static void
 193 sparc64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
 194 {
 195   struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
 196   ULONGEST state;
 197
 198   regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
 199   regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);
 200
 201   /* Clear the "in syscall" bit to prevent the kernel from
 202      messing with the PCs we just installed, if we happen to be
 203      within an interrupted system call that the kernel wants to
 204      restart.
 205
 206      Note that after we return from the dummy call, the TSTATE et al.
 207      registers will be automatically restored, and the kernel
 208      continues to restart the system call at this point.  */
 209   regcache_cooked_read_unsigned (regcache, SPARC64_STATE_REGNUM, &state);
 210   state &= ~TSTATE_SYSCALL;
 211   regcache_cooked_write_unsigned (regcache, SPARC64_STATE_REGNUM, state);
 212 }
 213
 214 static LONGEST
 215 sparc64_linux_get_syscall_number (struct gdbarch *gdbarch,
 216                                   ptid_t ptid)
 217 {
 218   struct regcache *regcache = get_thread_regcache (ptid);
 219   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 220   /* The content of a register.  */
 221   gdb_byte buf[8];
 222   /* The result.  */
 223   LONGEST ret;
 224
 225   /* Getting the system call number from the register.
 226      When dealing with the sparc architecture, this information
 227      is stored at the %g1 register.  */
 228   regcache_cooked_read (regcache, SPARC_G1_REGNUM, buf);
 229
 230   ret = extract_signed_integer (buf, 8, byte_order);
 231
 232   return ret;
 233 }
 234
 235 \f
 236 /* Implement the "get_longjmp_target" gdbarch method.  */
 237
 238 static int
 239 sparc64_linux_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc)
 240 {
 241   struct gdbarch *gdbarch = get_frame_arch (frame);
 242   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 243   CORE_ADDR jb_addr;
 244   gdb_byte buf[8];
 245
 246   jb_addr = get_frame_register_unsigned (frame, SPARC_O0_REGNUM);
 247
 248   /* setjmp and longjmp in SPARC64 are implemented in glibc using the
 249      setcontext and getcontext system calls respectively.  These
 250      system calls operate on ucontext_t structures, which happen to
 251      partially have the same structure than jmp_buf.  However the
 252      ucontext returned by getcontext, and thus the jmp_buf structure
 253      returned by setjmp, contains the context of the trap instruction
 254      in the glibc __[sig]setjmp wrapper, not the context of the user
 255      code calling setjmp.
 256
 257      %o7 in the jmp_buf structure is stored at offset 18*8 in the
 258      mc_gregs array, which is itself located at offset 32 into
 259      jmp_buf.  See bits/setjmp.h.  This register contains the address
 260      of the 'call setjmp' instruction in user code.
 261
 262      In order to determine the longjmp target address in the
 263      initiating frame we need to examine the call instruction itself,
 264      in particular whether the annul bit is set.  If it is not set
 265      then we need to jump over the instruction at the delay slot.  */
 266
 267   if (target_read_memory (jb_addr + 32 + (18 * 8), buf, 8))
 268     return 0;
 269
 270   *pc = extract_unsigned_integer (buf, 8, gdbarch_byte_order (gdbarch));
 271
 272   if (!sparc_is_annulled_branch_insn (*pc))
 273       *pc += 4; /* delay slot insn  */
 274   *pc += 4; /* call insn  */
 275
 276   return 1;
 277 }
 278
 279 \f
 280
 281 static void
 282 sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 283 {
 284   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 285
 286   linux_init_abi (info, gdbarch);
 287
 288   tdep->gregset = regset_alloc (gdbarch, sparc64_linux_supply_core_gregset,
 289                                 sparc64_linux_collect_core_gregset);
 290   tdep->sizeof_gregset = 288;
 291
 292   tdep->fpregset = regset_alloc (gdbarch, sparc64_linux_supply_core_fpregset,
 293                                  sparc64_linux_collect_core_fpregset);
 294   tdep->sizeof_fpregset = 280;
 295
 296   tramp_frame_prepend_unwinder (gdbarch, &sparc64_linux_rt_sigframe);
 297
 298   /* Hook in the DWARF CFI frame unwinder.  */
 299   dwarf2_append_unwinders (gdbarch);
 300
 301   sparc64_init_abi (info, gdbarch);
 302
 303   /* GNU/Linux has SVR4-style shared libraries...  */
 304   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 305   set_solib_svr4_fetch_link_map_offsets
 306     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 307
 308   /* ...which means that we need some special handling when doing
 309      prologue analysis.  */
 310   tdep->plt_entry_size = 16;
 311
 312   /* Enable TLS support.  */
 313   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 314                                              svr4_fetch_objfile_link_map);
 315
 316   /* Make sure we can single-step over signal return system calls.  */
 317   tdep->step_trap = sparc64_linux_step_trap;
 318
 319   /* Make sure we can single-step over longjmp calls.  */
 320   set_gdbarch_get_longjmp_target (gdbarch, sparc64_linux_get_longjmp_target);
 321
 322   set_gdbarch_write_pc (gdbarch, sparc64_linux_write_pc);
 323
 324   /* Functions for 'catch syscall'.  */
 325   set_xml_syscall_file_name (XML_SYSCALL_FILENAME_SPARC64);
 326   set_gdbarch_get_syscall_number (gdbarch,
 327                                   sparc64_linux_get_syscall_number);
 328 }
 329 \f
 330
 331 /* Provide a prototype to silence -Wmissing-prototypes.  */
 332 extern void _initialize_sparc64_linux_tdep (void);
 333
 334 void
 335 _initialize_sparc64_linux_tdep (void)
 336 {
 337   gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
 338                           GDB_OSABI_LINUX, sparc64_linux_init_abi);
 339 }