gnu/dist/gdb6/gdb/amd64nbsd-tdep.c

   1 /* Target-dependent code for NetBSD/amd64.
   2
   3    Copyright (C) 2003, 2004 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 2 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, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "arch-utils.h"
  24 #include "frame.h"
  25 #include "gdbcore.h"
  26 #include "osabi.h"
  27 #include "symtab.h"
  28
  29 #include "gdb_assert.h"
  30
  31 #include "amd64-tdep.h"
  32 #include "nbsd-tdep.h"
  33 #include "solib-svr4.h"
  34 #include "trad-frame.h"
  35 #include "frame-unwind.h"
  36
  37 /* Support for signal handlers.  */
  38
  39 /* Return whether the frame preceding NEXT_FRAME corresponds to a
  40    NetBSD sigtramp routine.  */
  41
  42 static int
  43 amd64nbsd_sigtramp_p (struct frame_info *next_frame)
  44 {
  45   CORE_ADDR pc = frame_pc_unwind (next_frame);
  46   char *name;
  47
  48   find_pc_partial_function (pc, &name, NULL, NULL);
  49   return nbsd_pc_in_sigtramp (pc, name);
  50 }
  51
  52 /* Assuming NEXT_FRAME is preceded by a frame corresponding to a
  53    NetBSD sigtramp routine, return the address of the associated
  54    mcontext structure.  */
  55
  56 static CORE_ADDR
  57 amd64nbsd_mcontext_addr (struct frame_info *next_frame)
  58 {
  59   CORE_ADDR addr;
  60
  61   /* The register %r15 points at `struct ucontext' upon entry of a
  62      signal trampoline.  */
  63   addr = frame_unwind_register_unsigned (next_frame, AMD64_R15_REGNUM);
  64
  65   /* The mcontext structure lives as offset 56 in `struct ucontext'.  */
  66   return addr + 56;
  67 }
  68 \f
  69 /* NetBSD 2.0 or later.  */
  70
  71 /* Mapping between the general-purpose registers in `struct reg'
  72    format and GDB's register cache layout.  */
  73
  74 /* From <machine/reg.h>.  */
  75 int amd64nbsd_r_reg_offset[] =
  76 {
  77   14 * 8,                       /* %rax */
  78   13 * 8,                       /* %rbx */
  79   3 * 8,                        /* %rcx */
  80   2 * 8,                        /* %rdx */
  81   1 * 8,                        /* %rsi */
  82   0 * 8,                        /* %rdi */
  83   12 * 8,                       /* %rbp */
  84   24 * 8,                       /* %rsp */
  85   4 * 8,                        /* %r8 .. */
  86   5 * 8,
  87   6 * 8,
  88   7 * 8,
  89   8 * 8,
  90   9 * 8,
  91   10 * 8,
  92   11 * 8,                       /* ... %r15 */
  93   21 * 8,                       /* %rip */
  94   23 * 8,                       /* %eflags */
  95   22 * 8,                       /* %cs */
  96   25 * 8,                       /* %ss */
  97   18 * 8,                       /* %ds */
  98   17 * 8,                       /* %es */
  99   16 * 8,                       /* %fs */
 100   15 * 8                        /* %gs */
 101 };
 102
 103 /* Kernel debuging support */
 104 static const int amd64nbsd_tf_reg_offset[] =
 105 {
 106   18 * 8,                       /* %rax */
 107   17 * 8,                       /* %rbx */
 108   10 * 8,                       /* %rcx */
 109   2 * 8,                        /* %rdx */
 110   1 * 8,                        /* %rsi */
 111   0 * 8,                        /* %rdi */
 112   16 * 8,                       /* %rbp */
 113   28 * 8,                       /* %rsp */
 114   4 * 8,                        /* %r8 .. */
 115   5 * 8,
 116   3 * 8,
 117   11 * 8,
 118   12 * 8,
 119   13 * 8,
 120   14 * 8,
 121   15 * 8,                       /* ... %r15 */
 122   25 * 8,                       /* %rip */
 123   27 * 8,                       /* %eflags */
 124   26 * 8,                       /* %cs */
 125   29 * 8,                       /* %ss */
 126   22 * 8,                       /* %ds */
 127   21 * 8,                       /* %es */
 128   20 * 8,                       /* %fs */
 129   19 * 8,                       /* %gs */
 130 };
 131
 132 static struct trad_frame_cache *
 133 amd64nbsd_trapframe_cache(struct frame_info *next_frame, void **this_cache)
 134 {
 135   struct trad_frame_cache *cache;
 136   CORE_ADDR func, sp, addr;
 137   ULONGEST cs, rip;
 138   char *name;
 139   int i;
 140
 141   if (*this_cache)
 142     return *this_cache;
 143
 144   cache = trad_frame_cache_zalloc (next_frame);
 145   *this_cache = cache;
 146
 147   func = frame_func_unwind (next_frame);
 148   sp = frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
 149
 150   find_pc_partial_function (func, &name, NULL, NULL);
 151
 152   /* There is an extra 'call' in the interrupt sequence - ignore the extra
 153    * return address */
 154   if (name && strncmp (name, "Xintr", 5) == 0)
 155     addr = sp + 8;              /* It's an interrupt frame.  */
 156   else
 157     addr = sp;
 158
 159   for (i = 0; i < ARRAY_SIZE (amd64nbsd_tf_reg_offset); i++)
 160     {
 161       if (amd64nbsd_tf_reg_offset[i] != -1)
 162         trad_frame_set_reg_addr (cache, i, addr + amd64nbsd_tf_reg_offset[i]);
 163
 164       /* Read %cs and %rip when we have the addresses to hand */
 165       if (i == AMD64_CS_REGNUM)
 166         cs = read_memory_unsigned_integer (addr + amd64nbsd_tf_reg_offset[i], 8);
 167       if (i == AMD64_RIP_REGNUM)
 168         rip = read_memory_unsigned_integer (addr + amd64nbsd_tf_reg_offset[i], 8);
 169     }
 170
 171   /* The trap frame layout was changed lf the %rip value is less than 2^16 it
 172    * is almost certainly the %ss of the old format. */
 173   if (rip < 2^16)
 174     {
 175
 176       for (i = 0; i < ARRAY_SIZE (amd64nbsd_tf_reg_offset); i++)
 177         {
 178
 179           if (amd64nbsd_tf_reg_offset[i] == -1)
 180             continue;
 181
 182           trad_frame_set_reg_addr (cache, i, addr + amd64nbsd_r_reg_offset[i]);
 183
 184           /* Read %cs when we have the address to hand */
 185           if (i == AMD64_CS_REGNUM)
 186             cs = read_memory_unsigned_integer (addr + amd64nbsd_r_reg_offset[i], 8);
 187         }
 188     }
 189
 190   if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
 191     {
 192       /* Trap from user space; terminate backtrace.  */
 193       trad_frame_set_id (cache, null_frame_id);
 194     }
 195   else
 196     {
 197       /* Construct the frame ID using the function start.  */
 198       trad_frame_set_id (cache, frame_id_build (sp + 16, func));
 199     }
 200
 201   return cache;
 202 }
 203
 204 static void
 205 amd64nbsd_trapframe_this_id (struct frame_info *next_frame,
 206                              void **this_cache, struct frame_id *this_id)
 207 {
 208   struct trad_frame_cache *cache =
 209     amd64nbsd_trapframe_cache (next_frame, this_cache);
 210
 211   trad_frame_get_id (cache, this_id);
 212 }
 213
 214 static void
 215 amd64nbsd_trapframe_prev_register (struct frame_info *next_frame,
 216                                    void **this_cache, int regnum,
 217                                    int *optimizedp, enum lval_type *lvalp,
 218                                    CORE_ADDR *addrp, int *realnump,
 219                                    gdb_byte *valuep)
 220 {
 221   struct trad_frame_cache *cache =
 222     amd64nbsd_trapframe_cache (next_frame, this_cache);
 223
 224   trad_frame_get_register (cache, next_frame, regnum,
 225                            optimizedp, lvalp, addrp, realnump, valuep);
 226 }
 227
 228 static int
 229 amd64nbsd_trapframe_sniffer (const struct frame_unwind *self,
 230                              struct frame_info *next_frame,
 231                              void **this_prologue_cache)
 232 {
 233   ULONGEST cs;
 234   char *name;
 235
 236   /* Check Current Privilege Level and bail out if we're not executing
 237      in kernel space.  */
 238   cs = frame_unwind_register_unsigned (next_frame, AMD64_CS_REGNUM);
 239   if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
 240     return 0;
 241
 242   find_pc_partial_function (frame_pc_unwind (next_frame), &name, NULL, NULL);
 243   return (name && ((strcmp (name, "alltraps") == 0)
 244                    || (strcmp (name, "calltrap") == 0)
 245                    || (strncmp (name, "Xtrap", 5) == 0)
 246                    || (strcmp (name, "osyscall1") == 0)
 247                    || (strcmp (name, "Xsyscall") == 0)
 248                    || (strncmp (name, "Xintr", 5) == 0)
 249                    || (strncmp (name, "Xresume", 7) == 0)
 250                    || (strncmp (name, "Xstray", 6) == 0)
 251                    || (strncmp (name, "Xrecurse", 8) == 0)
 252                    || (strncmp (name, "Xsoft", 5) == 0)
 253                    || (strcmp (name, "Xdoreti") == 0)));
 254 }
 255
 256 static const struct frame_unwind amd64nbsd_trapframe_unwind = {
 257   /* FIXME: kettenis/20051219: This really is more like an interrupt
 258      frame, but SIGTRAMP_FRAME would print <signal handler called>,
 259      which really is not what we want here.  */
 260   NORMAL_FRAME,
 261   amd64nbsd_trapframe_this_id,
 262   amd64nbsd_trapframe_prev_register,
 263   NULL,
 264   amd64nbsd_trapframe_sniffer
 265 };
 266 \f
 267
 268 static void
 269 amd64nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 270 {
 271   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 272
 273   /* Initialize general-purpose register set details first.  */
 274   tdep->gregset_reg_offset = amd64nbsd_r_reg_offset;
 275   tdep->gregset_num_regs = ARRAY_SIZE (amd64nbsd_r_reg_offset);
 276   tdep->sizeof_gregset = 26 * 8;
 277
 278   amd64_init_abi (info, gdbarch);
 279
 280   tdep->jb_pc_offset = 7 * 8;
 281
 282   /* NetBSD has its own convention for signal trampolines.  */
 283   tdep->sigtramp_p = amd64nbsd_sigtramp_p;
 284   tdep->sigcontext_addr = amd64nbsd_mcontext_addr;
 285   tdep->sc_reg_offset = amd64nbsd_r_reg_offset;
 286   tdep->sc_num_regs = ARRAY_SIZE (amd64nbsd_r_reg_offset);
 287
 288   /* NetBSD uses SVR4-style shared libraries.  */
 289   set_solib_svr4_fetch_link_map_offsets
 290     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 291
 292   /* Unwind kernel trap frames correctly.  */
 293   frame_unwind_prepend_unwinder (gdbarch, &amd64nbsd_trapframe_unwind);
 294 }
 295 \f
 296
 297 /* Provide a prototype to silence -Wmissing-prototypes.  */
 298 void _initialize_amd64nbsd_tdep (void);
 299
 300 void
 301 _initialize_amd64nbsd_ndep (void)
 302 {
 303   /* The NetBSD/amd64 native dependent code makes this assumption.  */
 304   gdb_assert (ARRAY_SIZE (amd64nbsd_r_reg_offset) == AMD64_NUM_GREGS);
 305
 306   gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
 307                           GDB_OSABI_NETBSD_ELF, amd64nbsd_init_abi);
 308 }