gdb/ia64-linux-tdep.c

   1 /* Target-dependent code for the IA-64 for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2013 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 "ia64-tdep.h"
  22 #include "arch-utils.h"
  23 #include "gdbcore.h"
  24 #include "regcache.h"
  25 #include "osabi.h"
  26 #include "solib-svr4.h"
  27 #include "symtab.h"
  28 #include "linux-tdep.h"
  29
  30 #include <ctype.h>
  31
  32 /* The sigtramp code is in a non-readable (executable-only) region
  33    of memory called the ``gate page''.  The addresses in question
  34    were determined by examining the system headers.  They are
  35    overly generous to allow for different pages sizes.  */
  36
  37 #define GATE_AREA_START 0xa000000000000100LL
  38 #define GATE_AREA_END   0xa000000000020000LL
  39
  40 /* Offset to sigcontext structure from frame of handler.  */
  41 #define IA64_LINUX_SIGCONTEXT_OFFSET 192
  42
  43 static int
  44 ia64_linux_pc_in_sigtramp (CORE_ADDR pc)
  45 {
  46   return (pc >= (CORE_ADDR) GATE_AREA_START && pc < (CORE_ADDR) GATE_AREA_END);
  47 }
  48
  49 /* IA-64 GNU/Linux specific function which, given a frame address and
  50    a register number, returns the address at which that register may be
  51    found.  0 is returned for registers which aren't stored in the
  52    sigcontext structure.  */
  53
  54 static CORE_ADDR
  55 ia64_linux_sigcontext_register_address (struct gdbarch *gdbarch,
  56                                         CORE_ADDR sp, int regno)
  57 {
  58   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  59   gdb_byte buf[8];
  60   CORE_ADDR sigcontext_addr = 0;
  61
  62   /* The address of the sigcontext area is found at offset 16 in the
  63      sigframe.  */
  64   read_memory (sp + 16, buf, 8);
  65   sigcontext_addr = extract_unsigned_integer (buf, 8, byte_order);
  66
  67   if (IA64_GR0_REGNUM <= regno && regno <= IA64_GR31_REGNUM)
  68     return sigcontext_addr + 200 + 8 * (regno - IA64_GR0_REGNUM);
  69   else if (IA64_BR0_REGNUM <= regno && regno <= IA64_BR7_REGNUM)
  70     return sigcontext_addr + 136 + 8 * (regno - IA64_BR0_REGNUM);
  71   else if (IA64_FR0_REGNUM <= regno && regno <= IA64_FR127_REGNUM)
  72     return sigcontext_addr + 464 + 16 * (regno - IA64_FR0_REGNUM);
  73   else
  74     switch (regno)
  75       {
  76       case IA64_IP_REGNUM :
  77         return sigcontext_addr + 40;
  78       case IA64_CFM_REGNUM :
  79         return sigcontext_addr + 48;
  80       case IA64_PSR_REGNUM :
  81         return sigcontext_addr + 56;            /* user mask only */
  82       /* sc_ar_rsc is provided, from which we could compute bspstore, but
  83          I don't think it's worth it.  Anyway, if we want it, it's at offset
  84          64.  */
  85       case IA64_BSP_REGNUM :
  86         return sigcontext_addr + 72;
  87       case IA64_RNAT_REGNUM :
  88         return sigcontext_addr + 80;
  89       case IA64_CCV_REGNUM :
  90         return sigcontext_addr + 88;
  91       case IA64_UNAT_REGNUM :
  92         return sigcontext_addr + 96;
  93       case IA64_FPSR_REGNUM :
  94         return sigcontext_addr + 104;
  95       case IA64_PFS_REGNUM :
  96         return sigcontext_addr + 112;
  97       case IA64_LC_REGNUM :
  98         return sigcontext_addr + 120;
  99       case IA64_PR_REGNUM :
 100         return sigcontext_addr + 128;
 101       default :
 102         return 0;
 103       }
 104 }
 105
 106 static void
 107 ia64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
 108 {
 109   ia64_write_pc (regcache, pc);
 110
 111   /* We must be careful with modifying the instruction-pointer: if we
 112      just interrupt a system call, the kernel would ordinarily try to
 113      restart it when we resume the inferior, which typically results
 114      in SIGSEGV or SIGILL.  We prevent this by clearing r10, which
 115      will tell the kernel that r8 does NOT contain a valid error code
 116      and hence it will skip system-call restart.
 117
 118      The clearing of r10 is safe as long as ia64_write_pc() is only
 119      called as part of setting up an inferior call.  */
 120   regcache_cooked_write_unsigned (regcache, IA64_GR10_REGNUM, 0);
 121 }
 122
 123 /* Implementation of `gdbarch_stap_is_single_operand', as defined in
 124    gdbarch.h.  */
 125
 126 static int
 127 ia64_linux_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
 128 {
 129   return ((isdigit (*s) && s[1] == '[' && s[2] == 'r') /* Displacement.  */
 130           || *s == 'r' /* Register value.  */
 131           || isdigit (*s));  /* Literal number.  */
 132 }
 133
 134 static void
 135 ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 136 {
 137   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 138   static const char *const stap_register_prefixes[] = { "r", NULL };
 139   static const char *const stap_register_indirection_prefixes[] = { "[",
 140                                                                     NULL };
 141   static const char *const stap_register_indirection_suffixes[] = { "]",
 142                                                                     NULL };
 143
 144   linux_init_abi (info, gdbarch);
 145
 146   /* Set the method of obtaining the sigcontext addresses at which
 147      registers are saved.  */
 148   tdep->sigcontext_register_address = ia64_linux_sigcontext_register_address;
 149
 150   /* Set the pc_in_sigtramp method.  */
 151   tdep->pc_in_sigtramp = ia64_linux_pc_in_sigtramp;
 152
 153   set_gdbarch_write_pc (gdbarch, ia64_linux_write_pc);
 154
 155   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 156
 157   set_solib_svr4_fetch_link_map_offsets
 158     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 159
 160   /* Enable TLS support.  */
 161   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 162                                              svr4_fetch_objfile_link_map);
 163
 164   /* SystemTap related.  */
 165   set_gdbarch_stap_register_prefixes (gdbarch, stap_register_prefixes);
 166   set_gdbarch_stap_register_indirection_prefixes (gdbarch,
 167                                           stap_register_indirection_prefixes);
 168   set_gdbarch_stap_register_indirection_suffixes (gdbarch,
 169                                             stap_register_indirection_suffixes);
 170   set_gdbarch_stap_gdb_register_prefix (gdbarch, "r");
 171   set_gdbarch_stap_is_single_operand (gdbarch,
 172                                       ia64_linux_stap_is_single_operand);
 173 }
 174
 175 /* Provide a prototype to silence -Wmissing-prototypes.  */
 176 extern initialize_file_ftype _initialize_ia64_linux_tdep;
 177
 178 void
 179 _initialize_ia64_linux_tdep (void)
 180 {
 181   gdbarch_register_osabi (bfd_arch_ia64, 0, GDB_OSABI_LINUX,
 182                           ia64_linux_init_abi);
 183 }