gdb/sparc64-linux-tdep.c

   1 /* Target-dependent code for GNU/Linux UltraSPARC.
   2
   3    Copyright (C) 2003, 2004, 2005, 2007, 2008 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 "frame.h"
  22 #include "frame-unwind.h"
  23 #include "dwarf2-frame.h"
  24 #include "regset.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 *this_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 *this_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 = get_frame_register_unsigned (this_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 = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
  88   if (base & 1)
  89     base += BIAS;
  90
  91   addr = get_frame_memory_unsigned (this_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 (struct frame_info *frame, unsigned long insn)
 108 {
 109   if (insn == 0x91d0206d)
 110     {
 111       ULONGEST sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);
 112       if (sp & 1)
 113         sp += BIAS;
 114
 115       /* The kernel puts the sigreturn registers on the stack,
 116          and this is where the signal unwinding state is take from
 117          when returning from a signal.
 118
 119          A siginfo_t sits 192 bytes from the base of the stack.  This
 120          siginfo_t is 128 bytes, and is followed by the sigreturn
 121          register save area.  The saved PC sits at a 136 byte offset
 122          into there.  */
 123
 124       return read_memory_unsigned_integer (sp + 192 + 128 + 136, 8);
 125     }
 126
 127   return 0;
 128 }
 129 \f
 130
 131 const struct sparc_gregset sparc64_linux_core_gregset =
 132 {
 133   32 * 8,                       /* %tstate */
 134   33 * 8,                       /* %tpc */
 135   34 * 8,                       /* %tnpc */
 136   35 * 8,                       /* %y */
 137   -1,                           /* %wim */
 138   -1,                           /* %tbr */
 139   1 * 8,                        /* %g1 */
 140   16 * 8,                       /* %l0 */
 141   8,                            /* y size */
 142 };
 143 \f
 144
 145 static void
 146 sparc64_linux_supply_core_gregset (const struct regset *regset,
 147                                    struct regcache *regcache,
 148                                    int regnum, const void *gregs, size_t len)
 149 {
 150   sparc64_supply_gregset (&sparc64_linux_core_gregset, regcache, regnum, gregs);
 151 }
 152
 153 static void
 154 sparc64_linux_collect_core_gregset (const struct regset *regset,
 155                                     const struct regcache *regcache,
 156                                     int regnum, void *gregs, size_t len)
 157 {
 158   sparc64_collect_gregset (&sparc64_linux_core_gregset, regcache, regnum, gregs);
 159 }
 160
 161 static void
 162 sparc64_linux_supply_core_fpregset (const struct regset *regset,
 163                                     struct regcache *regcache,
 164                                     int regnum, const void *fpregs, size_t len)
 165 {
 166   sparc64_supply_fpregset (regcache, regnum, fpregs);
 167 }
 168
 169 static void
 170 sparc64_linux_collect_core_fpregset (const struct regset *regset,
 171                                      const struct regcache *regcache,
 172                                      int regnum, void *fpregs, size_t len)
 173 {
 174   sparc64_collect_fpregset (regcache, regnum, fpregs);
 175 }
 176
 177 /* Set the program counter for process PTID to PC.  */
 178
 179 #define TSTATE_SYSCALL  0x0000000000000020ULL
 180
 181 static void
 182 sparc64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
 183 {
 184   struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
 185   ULONGEST state;
 186
 187   regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
 188   regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);
 189
 190   /* Clear the "in syscall" bit to prevent the kernel from
 191      messing with the PCs we just installed, if we happen to be
 192      within an interrupted system call that the kernel wants to
 193      restart.
 194
 195      Note that after we return from the dummy call, the TSTATE et al.
 196      registers will be automatically restored, and the kernel
 197      continues to restart the system call at this point.  */
 198   regcache_cooked_read_unsigned (regcache, SPARC64_STATE_REGNUM, &state);
 199   state &= ~TSTATE_SYSCALL;
 200   regcache_cooked_write_unsigned (regcache, SPARC64_STATE_REGNUM, state);
 201 }
 202
 203 \f
 204
 205 static void
 206 sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 207 {
 208   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 209
 210   tdep->gregset = regset_alloc (gdbarch, sparc64_linux_supply_core_gregset,
 211                                 sparc64_linux_collect_core_gregset);
 212   tdep->sizeof_gregset = 288;
 213
 214   tdep->fpregset = regset_alloc (gdbarch, sparc64_linux_supply_core_fpregset,
 215                                  sparc64_linux_collect_core_fpregset);
 216   tdep->sizeof_fpregset = 280;
 217
 218   tramp_frame_prepend_unwinder (gdbarch, &sparc64_linux_rt_sigframe);
 219
 220   /* Hook in the DWARF CFI frame unwinder.  */
 221   dwarf2_append_unwinders (gdbarch);
 222
 223   sparc64_init_abi (info, gdbarch);
 224
 225   /* GNU/Linux has SVR4-style shared libraries...  */
 226   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 227   set_solib_svr4_fetch_link_map_offsets
 228     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 229
 230   /* ...which means that we need some special handling when doing
 231      prologue analysis.  */
 232   tdep->plt_entry_size = 16;
 233
 234   /* Enable TLS support.  */
 235   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 236                                              svr4_fetch_objfile_link_map);
 237
 238   /* Make sure we can single-step over signal return system calls.  */
 239   tdep->step_trap = sparc64_linux_step_trap;
 240
 241   set_gdbarch_write_pc (gdbarch, sparc64_linux_write_pc);
 242 }
 243 \f
 244
 245 /* Provide a prototype to silence -Wmissing-prototypes.  */
 246 extern void _initialize_sparc64_linux_tdep (void);
 247
 248 void
 249 _initialize_sparc64_linux_tdep (void)
 250 {
 251   gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
 252                           GDB_OSABI_LINUX, sparc64_linux_init_abi);
 253 }