gdb/ia64-linux-tdep.c

   1 /* Target-dependent code for the IA-64 for GDB, the GNU debugger.
   2
   3    Copyright 2000, 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., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, 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
  28 /* The sigtramp code is in a non-readable (executable-only) region
  29    of memory called the ``gate page''.  The addresses in question
  30    were determined by examining the system headers.  They are
  31    overly generous to allow for different pages sizes. */
  32
  33 #define GATE_AREA_START 0xa000000000000100LL
  34 #define GATE_AREA_END   0xa000000000020000LL
  35
  36 /* Offset to sigcontext structure from frame of handler */
  37 #define IA64_LINUX_SIGCONTEXT_OFFSET 192
  38
  39 int
  40 ia64_linux_in_sigtramp (CORE_ADDR pc, char *func_name)
  41 {
  42   return (pc >= (CORE_ADDR) GATE_AREA_START && pc < (CORE_ADDR) GATE_AREA_END);
  43 }
  44
  45 /* IA-64 GNU/Linux specific function which, given a frame address and
  46    a register number, returns the address at which that register may be
  47    found.  0 is returned for registers which aren't stored in the the
  48    sigcontext structure. */
  49
  50 CORE_ADDR
  51 ia64_linux_sigcontext_register_address (CORE_ADDR sp, int regno)
  52 {
  53   char buf[8];
  54   CORE_ADDR sigcontext_addr = 0;
  55
  56   /* The address of the sigcontext area is found at offset 16 in the sigframe.  */
  57   read_memory (sp + 16, buf, 8);
  58   sigcontext_addr = extract_unsigned_integer (buf, 8);
  59
  60   if (IA64_GR0_REGNUM <= regno && regno <= IA64_GR31_REGNUM)
  61     return sigcontext_addr + 200 + 8 * (regno - IA64_GR0_REGNUM);
  62   else if (IA64_BR0_REGNUM <= regno && regno <= IA64_BR7_REGNUM)
  63     return sigcontext_addr + 136 + 8 * (regno - IA64_BR0_REGNUM);
  64   else if (IA64_FR0_REGNUM <= regno && regno <= IA64_FR127_REGNUM)
  65     return sigcontext_addr + 464 + 16 * (regno - IA64_FR0_REGNUM);
  66   else
  67     switch (regno)
  68       {
  69       case IA64_IP_REGNUM :
  70         return sigcontext_addr + 40;
  71       case IA64_CFM_REGNUM :
  72         return sigcontext_addr + 48;
  73       case IA64_PSR_REGNUM :
  74         return sigcontext_addr + 56;            /* user mask only */
  75       /* sc_ar_rsc is provided, from which we could compute bspstore, but
  76          I don't think it's worth it.  Anyway, if we want it, it's at offset
  77          64 */
  78       case IA64_BSP_REGNUM :
  79         return sigcontext_addr + 72;
  80       case IA64_RNAT_REGNUM :
  81         return sigcontext_addr + 80;
  82       case IA64_CCV_REGNUM :
  83         return sigcontext_addr + 88;
  84       case IA64_UNAT_REGNUM :
  85         return sigcontext_addr + 96;
  86       case IA64_FPSR_REGNUM :
  87         return sigcontext_addr + 104;
  88       case IA64_PFS_REGNUM :
  89         return sigcontext_addr + 112;
  90       case IA64_LC_REGNUM :
  91         return sigcontext_addr + 120;
  92       case IA64_PR_REGNUM :
  93         return sigcontext_addr + 128;
  94       default :
  95         return 0;
  96       }
  97 }
  98
  99 void
 100 ia64_linux_write_pc (CORE_ADDR pc, ptid_t ptid)
 101 {
 102   ia64_write_pc (pc, ptid);
 103
 104   /* We must be careful with modifying the instruction-pointer: if we
 105      just interrupt a system call, the kernel would ordinarily try to
 106      restart it when we resume the inferior, which typically results
 107      in SIGSEGV or SIGILL.  We prevent this by clearing r10, which
 108      will tell the kernel that r8 does NOT contain a valid error code
 109      and hence it will skip system-call restart.
 110
 111      The clearing of r10 is safe as long as ia64_write_pc() is only
 112      called as part of setting up an inferior call.  */
 113   write_register_pid (IA64_GR10_REGNUM, 0, ptid);
 114 }