gdb/sparc64-linux-tdep.c

   1 /* Target-dependent code for GNU/Linux UltraSPARC.
   2
   3    Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "frame.h"
  23 #include "frame-unwind.h"
  24 #include "dwarf2-frame.h"
  25 #include "regset.h"
  26 #include "regcache.h"
  27 #include "gdbarch.h"
  28 #include "gdbcore.h"
  29 #include "osabi.h"
  30 #include "solib-svr4.h"
  31 #include "symtab.h"
  32 #include "trad-frame.h"
  33 #include "tramp-frame.h"
  34
  35 #include "sparc64-tdep.h"
  36
  37 /* Signal trampoline support.  */
  38
  39 static void sparc64_linux_sigframe_init (const struct tramp_frame *self,
  40                                          struct frame_info *this_frame,
  41                                          struct trad_frame_cache *this_cache,
  42                                          CORE_ADDR func);
  43
  44 /* See sparc-linux-tdep.c for details.  Note that 64-bit binaries only
  45    use RT signals.  */
  46
  47 static const struct tramp_frame sparc64_linux_rt_sigframe =
  48 {
  49   SIGTRAMP_FRAME,
  50   4,
  51   {
  52     { 0x82102065, -1 },         /* mov __NR_rt_sigreturn, %g1 */
  53     { 0x91d0206d, -1 },         /* ta  0x6d */
  54     { TRAMP_SENTINEL_INSN, -1 }
  55   },
  56   sparc64_linux_sigframe_init
  57 };
  58
  59 static void
  60 sparc64_linux_sigframe_init (const struct tramp_frame *self,
  61                              struct frame_info *this_frame,
  62                              struct trad_frame_cache *this_cache,
  63                              CORE_ADDR func)
  64 {
  65   CORE_ADDR base, addr, sp_addr;
  66   int regnum;
  67
  68   base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM);
  69   base += 128;
  70
  71   /* Offsets from <bits/sigcontext.h>.  */
  72
  73   /* Since %g0 is always zero, keep the identity encoding.  */
  74   addr = base + 8;
  75   sp_addr = base + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 8);
  76   for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
  77     {
  78       trad_frame_set_reg_addr (this_cache, regnum, addr);
  79       addr += 8;
  80     }
  81
  82   trad_frame_set_reg_addr (this_cache, SPARC64_STATE_REGNUM, addr + 0);
  83   trad_frame_set_reg_addr (this_cache, SPARC64_PC_REGNUM, addr + 8);
  84   trad_frame_set_reg_addr (this_cache, SPARC64_NPC_REGNUM, addr + 16);
  85   trad_frame_set_reg_addr (this_cache, SPARC64_Y_REGNUM, addr + 24);
  86   trad_frame_set_reg_addr (this_cache, SPARC64_FPRS_REGNUM, addr + 28);
  87
  88   base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
  89   if (base & 1)
  90     base += BIAS;
  91
  92   addr = get_frame_memory_unsigned (this_frame, sp_addr, 8);
  93   if (addr & 1)
  94     addr += BIAS;
  95
  96   for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
  97     {
  98       trad_frame_set_reg_addr (this_cache, regnum, addr);
  99       addr += 8;
 100     }
 101   trad_frame_set_id (this_cache, frame_id_build (base, func));
 102 }
 103 \f
 104 /* Return the address of a system call's alternative return
 105    address.  */
 106
 107 static CORE_ADDR
 108 sparc64_linux_step_trap (struct frame_info *frame, unsigned long insn)
 109 {
 110   if (insn == 0x91d0206d)
 111     {
 112       ULONGEST sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);
 113       if (sp & 1)
 114         sp += BIAS;
 115
 116       /* The kernel puts the sigreturn registers on the stack,
 117          and this is where the signal unwinding state is take from
 118          when returning from a signal.
 119
 120          A siginfo_t sits 192 bytes from the base of the stack.  This
 121          siginfo_t is 128 bytes, and is followed by the sigreturn
 122          register save area.  The saved PC sits at a 136 byte offset
 123          into there.  */
 124
 125       return read_memory_unsigned_integer (sp + 192 + 128 + 136, 8);
 126     }
 127
 128   return 0;
 129 }
 130 \f
 131
 132 const struct sparc_gregset sparc64_linux_core_gregset =
 133 {
 134   32 * 8,                       /* %tstate */
 135   33 * 8,                       /* %tpc */
 136   34 * 8,                       /* %tnpc */
 137   35 * 8,                       /* %y */
 138   -1,                           /* %wim */
 139   -1,                           /* %tbr */
 140   1 * 8,                        /* %g1 */
 141   16 * 8,                       /* %l0 */
 142   8,                            /* y size */
 143 };
 144 \f
 145
 146 static void
 147 sparc64_linux_supply_core_gregset (const struct regset *regset,
 148                                    struct regcache *regcache,
 149                                    int regnum, const void *gregs, size_t len)
 150 {
 151   sparc64_supply_gregset (&sparc64_linux_core_gregset, regcache, regnum, gregs);
 152 }
 153
 154 static void
 155 sparc64_linux_collect_core_gregset (const struct regset *regset,
 156                                     const struct regcache *regcache,
 157                                     int regnum, void *gregs, size_t len)
 158 {
 159   sparc64_collect_gregset (&sparc64_linux_core_gregset, regcache, regnum, gregs);
 160 }
 161
 162 static void
 163 sparc64_linux_supply_core_fpregset (const struct regset *regset,
 164                                     struct regcache *regcache,
 165                                     int regnum, const void *fpregs, size_t len)
 166 {
 167   sparc64_supply_fpregset (regcache, regnum, fpregs);
 168 }
 169
 170 static void
 171 sparc64_linux_collect_core_fpregset (const struct regset *regset,
 172                                      const struct regcache *regcache,
 173                                      int regnum, void *fpregs, size_t len)
 174 {
 175   sparc64_collect_fpregset (regcache, regnum, fpregs);
 176 }
 177
 178 /* Set the program counter for process PTID to PC.  */
 179
 180 #define TSTATE_SYSCALL  0x0000000000000020ULL
 181
 182 static void
 183 sparc64_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
 184 {
 185   struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
 186   ULONGEST state;
 187
 188   regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
 189   regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);
 190
 191   /* Clear the "in syscall" bit to prevent the kernel from
 192      messing with the PCs we just installed, if we happen to be
 193      within an interrupted system call that the kernel wants to
 194      restart.
 195
 196      Note that after we return from the dummy call, the TSTATE et al.
 197      registers will be automatically restored, and the kernel
 198      continues to restart the system call at this point.  */
 199   regcache_cooked_read_unsigned (regcache, SPARC64_STATE_REGNUM, &state);
 200   state &= ~TSTATE_SYSCALL;
 201   regcache_cooked_write_unsigned (regcache, SPARC64_STATE_REGNUM, state);
 202 }
 203
 204 \f
 205
 206 static void
 207 sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 208 {
 209   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 210
 211   tdep->gregset = regset_alloc (gdbarch, sparc64_linux_supply_core_gregset,
 212                                 sparc64_linux_collect_core_gregset);
 213   tdep->sizeof_gregset = 288;
 214
 215   tdep->fpregset = regset_alloc (gdbarch, sparc64_linux_supply_core_fpregset,
 216                                  sparc64_linux_collect_core_fpregset);
 217   tdep->sizeof_fpregset = 280;
 218
 219   tramp_frame_prepend_unwinder (gdbarch, &sparc64_linux_rt_sigframe);
 220
 221   /* Hook in the DWARF CFI frame unwinder.  */
 222   dwarf2_append_unwinders (gdbarch);
 223
 224   sparc64_init_abi (info, gdbarch);
 225
 226   /* GNU/Linux has SVR4-style shared libraries...  */
 227   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 228   set_solib_svr4_fetch_link_map_offsets
 229     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 230
 231   /* ...which means that we need some special handling when doing
 232      prologue analysis.  */
 233   tdep->plt_entry_size = 16;
 234
 235   /* Enable TLS support.  */
 236   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 237                                              svr4_fetch_objfile_link_map);
 238
 239   /* Make sure we can single-step over signal return system calls.  */
 240   tdep->step_trap = sparc64_linux_step_trap;
 241
 242   set_gdbarch_write_pc (gdbarch, sparc64_linux_write_pc);
 243 }
 244 \f
 245
 246 /* Provide a prototype to silence -Wmissing-prototypes.  */
 247 extern void _initialize_sparc64_linux_tdep (void);
 248
 249 void
 250 _initialize_sparc64_linux_tdep (void)
 251 {
 252   gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
 253                           GDB_OSABI_LINUX, sparc64_linux_init_abi);
 254 }