1/* Target-dependent code for the IA-64 for GDB, the GNU debugger.
2
3   Copyright (C) 2000, 2004, 2005, 2007 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
29/* The sigtramp code is in a non-readable (executable-only) region
30   of memory called the ``gate page''.  The addresses in question
31   were determined by examining the system headers.  They are
32   overly generous to allow for different pages sizes. */
33
34#define GATE_AREA_START 0xa000000000000100LL
35#define GATE_AREA_END   0xa000000000020000LL
36
37/* Offset to sigcontext structure from frame of handler */
38#define IA64_LINUX_SIGCONTEXT_OFFSET 192
39
40static int
41ia64_linux_pc_in_sigtramp (CORE_ADDR pc)
42{
43  return (pc >= (CORE_ADDR) GATE_AREA_START && pc < (CORE_ADDR) GATE_AREA_END);
44}
45
46/* IA-64 GNU/Linux specific function which, given a frame address and
47   a register number, returns the address at which that register may be
48   found.  0 is returned for registers which aren't stored in the the
49   sigcontext structure. */
50
51static CORE_ADDR
52ia64_linux_sigcontext_register_address (CORE_ADDR sp, int regno)
53{
54  char buf[8];
55  CORE_ADDR sigcontext_addr = 0;
56
57  /* The address of the sigcontext area is found at offset 16 in the sigframe.  */
58  read_memory (sp + 16, buf, 8);
59  sigcontext_addr = extract_unsigned_integer (buf, 8);
60
61  if (IA64_GR0_REGNUM <= regno && regno <= IA64_GR31_REGNUM)
62    return sigcontext_addr + 200 + 8 * (regno - IA64_GR0_REGNUM);
63  else if (IA64_BR0_REGNUM <= regno && regno <= IA64_BR7_REGNUM)
64    return sigcontext_addr + 136 + 8 * (regno - IA64_BR0_REGNUM);
65  else if (IA64_FR0_REGNUM <= regno && regno <= IA64_FR127_REGNUM)
66    return sigcontext_addr + 464 + 16 * (regno - IA64_FR0_REGNUM);
67  else
68    switch (regno)
69      {
70      case IA64_IP_REGNUM :
71	return sigcontext_addr + 40;
72      case IA64_CFM_REGNUM :
73	return sigcontext_addr + 48;
74      case IA64_PSR_REGNUM :
75	return sigcontext_addr + 56;		/* user mask only */
76      /* sc_ar_rsc is provided, from which we could compute bspstore, but
77	 I don't think it's worth it.  Anyway, if we want it, it's at offset
78	 64 */
79      case IA64_BSP_REGNUM :
80	return sigcontext_addr + 72;
81      case IA64_RNAT_REGNUM :
82	return sigcontext_addr + 80;
83      case IA64_CCV_REGNUM :
84	return sigcontext_addr + 88;
85      case IA64_UNAT_REGNUM :
86	return sigcontext_addr + 96;
87      case IA64_FPSR_REGNUM :
88	return sigcontext_addr + 104;
89      case IA64_PFS_REGNUM :
90	return sigcontext_addr + 112;
91      case IA64_LC_REGNUM :
92	return sigcontext_addr + 120;
93      case IA64_PR_REGNUM :
94	return sigcontext_addr + 128;
95      default :
96	return 0;
97      }
98}
99
100static void
101ia64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
102{
103  ia64_write_pc (regcache, pc);
104
105  /* We must be careful with modifying the instruction-pointer: if we
106     just interrupt a system call, the kernel would ordinarily try to
107     restart it when we resume the inferior, which typically results
108     in SIGSEGV or SIGILL.  We prevent this by clearing r10, which
109     will tell the kernel that r8 does NOT contain a valid error code
110     and hence it will skip system-call restart.
111
112     The clearing of r10 is safe as long as ia64_write_pc() is only
113     called as part of setting up an inferior call.  */
114  regcache_cooked_write_unsigned (regcache, IA64_GR10_REGNUM, 0);
115}
116
117static void
118ia64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
119{
120  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
121
122  /* Set the method of obtaining the sigcontext addresses at which
123     registers are saved.  */
124  tdep->sigcontext_register_address = ia64_linux_sigcontext_register_address;
125
126  /* Set the pc_in_sigtramp method.  */
127  tdep->pc_in_sigtramp = ia64_linux_pc_in_sigtramp;
128
129  set_gdbarch_write_pc (gdbarch, ia64_linux_write_pc);
130
131  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
132
133  /* Enable TLS support.  */
134  set_gdbarch_fetch_tls_load_module_address (gdbarch,
135                                             svr4_fetch_objfile_link_map);
136}
137
138void
139_initialize_ia64_linux_tdep (void)
140{
141  gdbarch_register_osabi (bfd_arch_ia64, 0, GDB_OSABI_LINUX,
142			  ia64_linux_init_abi);
143}
144