gdb/sparc64-linux-tdep.c

   1 /* Target-dependent code for GNU/Linux UltraSPARC.
   2
   3    Copyright (C) 2003, 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 "frame.h"
  24 #include "frame-unwind.h"
  25 #include "regcache.h"
  26 #include "gdbarch.h"
  27 #include "gdbcore.h"
  28 #include "osabi.h"
  29 #include "solib-svr4.h"
  30 #include "symtab.h"
  31 #include "trad-frame.h"
  32 #include "tramp-frame.h"
  33
  34 #include "sparc64-tdep.h"
  35
  36 /* Signal trampoline support.  */
  37
  38 static void sparc64_linux_sigframe_init (const struct tramp_frame *self,
  39                                          struct frame_info *next_frame,
  40                                          struct trad_frame_cache *this_cache,
  41                                          CORE_ADDR func);
  42
  43 /* See sparc-linux-tdep.c for details.  Note that 64-bit binaries only
  44    use RT signals.  */
  45
  46 static const struct tramp_frame sparc64_linux_rt_sigframe =
  47 {
  48   SIGTRAMP_FRAME,
  49   4,
  50   {
  51     { 0x82102065, -1 },         /* mov __NR_rt_sigreturn, %g1 */
  52     { 0x91d0206d, -1 },         /* ta  0x6d */
  53     { TRAMP_SENTINEL_INSN, -1 }
  54   },
  55   sparc64_linux_sigframe_init
  56 };
  57
  58 static void
  59 sparc64_linux_sigframe_init (const struct tramp_frame *self,
  60                              struct frame_info *next_frame,
  61                              struct trad_frame_cache *this_cache,
  62                              CORE_ADDR func)
  63 {
  64   CORE_ADDR base, addr, sp_addr;
  65   int regnum;
  66
  67   base = frame_unwind_register_unsigned (next_frame, SPARC_O1_REGNUM);
  68   base += 128;
  69
  70   /* Offsets from <bits/sigcontext.h>.  */
  71
  72   /* Since %g0 is always zero, keep the identity encoding.  */
  73   addr = base + 8;
  74   sp_addr = base + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 8);
  75   for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
  76     {
  77       trad_frame_set_reg_addr (this_cache, regnum, addr);
  78       addr += 8;
  79     }
  80
  81   trad_frame_set_reg_addr (this_cache, SPARC64_STATE_REGNUM, addr + 0);
  82   trad_frame_set_reg_addr (this_cache, SPARC64_PC_REGNUM, addr + 8);
  83   trad_frame_set_reg_addr (this_cache, SPARC64_NPC_REGNUM, addr + 16);
  84   trad_frame_set_reg_addr (this_cache, SPARC64_Y_REGNUM, addr + 24);
  85   trad_frame_set_reg_addr (this_cache, SPARC64_FPRS_REGNUM, addr + 28);
  86
  87   base = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
  88   if (base & 1)
  89     base += BIAS;
  90
  91   addr = get_frame_memory_unsigned (next_frame, sp_addr, 8);
  92   if (addr & 1)
  93     addr += BIAS;
  94
  95   for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
  96     {
  97       trad_frame_set_reg_addr (this_cache, regnum, addr);
  98       addr += 8;
  99     }
 100   trad_frame_set_id (this_cache, frame_id_build (base, func));
 101 }
 102 \f
 103 /* Return the address of a system call's alternative return
 104    address.  */
 105
 106 static CORE_ADDR
 107 sparc64_linux_step_trap (unsigned long insn)
 108 {
 109   if (insn == 0x91d0206d)
 110     {
 111       ULONGEST sp;
 112
 113       regcache_cooked_read_unsigned (current_regcache,
 114                                      SPARC_SP_REGNUM, &sp);
 115       if (sp & 1)
 116         sp += BIAS;
 117
 118       /* The kernel puts the sigreturn registers on the stack,
 119          and this is where the signal unwinding state is take from
 120          when returning from a signal.
 121
 122          A siginfo_t sits 192 bytes from the base of the stack.  This
 123          siginfo_t is 128 bytes, and is followed by the sigreturn
 124          register save area.  The saved PC sits at a 136 byte offset
 125          into there.  */
 126
 127       return read_memory_unsigned_integer (sp + 192 + 128 + 136, 8);
 128     }
 129
 130   return 0;
 131 }
 132 \f
 133
 134 static void
 135 sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 136 {
 137   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 138
 139   tramp_frame_prepend_unwinder (gdbarch, &sparc64_linux_rt_sigframe);
 140
 141   sparc64_init_abi (info, gdbarch);
 142
 143   /* GNU/Linux has SVR4-style shared libraries...  */
 144   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 145   set_solib_svr4_fetch_link_map_offsets
 146     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 147
 148   /* ...which means that we need some special handling when doing
 149      prologue analysis.  */
 150   tdep->plt_entry_size = 16;
 151
 152   /* Enable TLS support.  */
 153   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 154                                              svr4_fetch_objfile_link_map);
 155
 156   /* Make sure we can single-step over signal return system calls.  */
 157   tdep->step_trap = sparc64_linux_step_trap;
 158 }
 159 \f
 160
 161 /* Provide a prototype to silence -Wmissing-prototypes.  */
 162 extern void _initialize_sparc64_linux_tdep (void);
 163
 164 void
 165 _initialize_sparc64_linux_tdep (void)
 166 {
 167   gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
 168                           GDB_OSABI_LINUX, sparc64_linux_init_abi);
 169 }