gdb/ia64-linux-tdep.c

   1 /* Target-dependent code for the IA-64 for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000, 2004, 2005 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 "ia64-tdep.h"
  24 #include "arch-utils.h"
  25 #include "gdbcore.h"
  26 #include "regcache.h"
  27 #include "osabi.h"
  28 #include "solib-svr4.h"
  29
  30 /* The sigtramp code is in a non-readable (executable-only) region
  31    of memory called the ``gate page''.  The addresses in question
  32    were determined by examining the system headers.  They are
  33    overly generous to allow for different pages sizes. */
  34
  35 #define GATE_AREA_START 0xa000000000000100LL
  36 #define GATE_AREA_END   0xa000000000020000LL
  37
  38 /* Offset to sigcontext structure from frame of handler */
  39 #define IA64_LINUX_SIGCONTEXT_OFFSET 192
  40
  41 int
  42 ia64_linux_in_sigtramp (CORE_ADDR pc, char *func_name)
  43 {
  44   return (pc >= (CORE_ADDR) GATE_AREA_START && pc < (CORE_ADDR) GATE_AREA_END);
  45 }
  46
  47 /* IA-64 GNU/Linux specific function which, given a frame address and
  48    a register number, returns the address at which that register may be
  49    found.  0 is returned for registers which aren't stored in the the
  50    sigcontext structure. */
  51
  52 static CORE_ADDR
  53 ia64_linux_sigcontext_register_address (CORE_ADDR sp, int regno)
  54 {
  55   char buf[8];
  56   CORE_ADDR sigcontext_addr = 0;
  57
  58   /* The address of the sigcontext area is found at offset 16 in the sigframe.  */
  59   read_memory (sp + 16, buf, 8);
  60   sigcontext_addr = extract_unsigned_integer (buf, 8);
  61
  62   if (IA64_GR0_REGNUM <= regno && regno <= IA64_GR31_REGNUM)
  63     return sigcontext_addr + 200 + 8 * (regno - IA64_GR0_REGNUM);
  64   else if (IA64_BR0_REGNUM <= regno && regno <= IA64_BR7_REGNUM)
  65     return sigcontext_addr + 136 + 8 * (regno - IA64_BR0_REGNUM);
  66   else if (IA64_FR0_REGNUM <= regno && regno <= IA64_FR127_REGNUM)
  67     return sigcontext_addr + 464 + 16 * (regno - IA64_FR0_REGNUM);
  68   else
  69     switch (regno)
  70       {
  71       case IA64_IP_REGNUM :
  72         return sigcontext_addr + 40;
  73       case IA64_CFM_REGNUM :
  74         return sigcontext_addr + 48;
  75       case IA64_PSR_REGNUM :
  76         return sigcontext_addr + 56;            /* user mask only */
  77       /* sc_ar_rsc is provided, from which we could compute bspstore, but
  78          I don't think it's worth it.  Anyway, if we want it, it's at offset
  79          64 */
  80       case IA64_BSP_REGNUM :
  81         return sigcontext_addr + 72;
  82       case IA64_RNAT_REGNUM :
  83         return sigcontext_addr + 80;
  84       case IA64_CCV_REGNUM :
  85         return sigcontext_addr + 88;
  86       case IA64_UNAT_REGNUM :
  87         return sigcontext_addr + 96;
  88       case IA64_FPSR_REGNUM :
  89         return sigcontext_addr + 104;
  90       case IA64_PFS_REGNUM :
  91         return sigcontext_addr + 112;
  92       case IA64_LC_REGNUM :
  93         return sigcontext_addr + 120;
  94       case IA64_PR_REGNUM :
  95         return sigcontext_addr + 128;
  96       default :
  97         return 0;
  98       }
  99 }
 100
 101 static void
 102 ia64_linux_write_pc (CORE_ADDR pc, ptid_t ptid)
 103 {
 104   ia64_write_pc (pc, ptid);
 105
 106   /* We must be careful with modifying the instruction-pointer: if we
 107      just interrupt a system call, the kernel would ordinarily try to
 108      restart it when we resume the inferior, which typically results
 109      in SIGSEGV or SIGILL.  We prevent this by clearing r10, which
 110      will tell the kernel that r8 does NOT contain a valid error code
 111      and hence it will skip system-call restart.
 112
 113      The clearing of r10 is safe as long as ia64_write_pc() is only
 114      called as part of setting up an inferior call.  */
 115   write_register_pid (IA64_GR10_REGNUM, 0, ptid);
 116 }
 117
 118 static void
 119 ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 120 {
 121   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 122
 123   /* Set the method of obtaining the sigcontext addresses at which
 124      registers are saved.  */
 125   tdep->sigcontext_register_address = ia64_linux_sigcontext_register_address;
 126
 127   set_gdbarch_write_pc (gdbarch, ia64_linux_write_pc);
 128
 129   /* Enable TLS support.  */
 130   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 131                                              svr4_fetch_objfile_link_map);
 132 }
 133
 134 void
 135 _initialize_ia64_linux_tdep (void)
 136 {
 137   gdbarch_register_osabi (bfd_arch_ia64, 0, GDB_OSABI_LINUX,
 138                           ia64_linux_init_abi);
 139 }