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[/] [openrisc/] [trunk/] [gnu-old/] [gdb-7.1/] [gdb/] [sparc-linux-tdep.c] - Blame information for rev 842

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1 227 jeremybenn
/* Target-dependent code for GNU/Linux SPARC.
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   Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010
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   Free Software Foundation, Inc.
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   This file is part of GDB.
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8
   This program is free software; you can redistribute it and/or modify
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   it under the terms of the GNU General Public License as published by
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   the Free Software Foundation; either version 3 of the License, or
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   (at your option) any later version.
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   This program is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   GNU General Public License for more details.
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   You should have received a copy of the GNU General Public License
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   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
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#include "defs.h"
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#include "dwarf2-frame.h"
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#include "frame.h"
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#include "frame-unwind.h"
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#include "gdbtypes.h"
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#include "regset.h"
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#include "gdbarch.h"
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#include "gdbcore.h"
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#include "osabi.h"
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#include "regcache.h"
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#include "solib-svr4.h"
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#include "symtab.h"
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#include "trad-frame.h"
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#include "tramp-frame.h"
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#include "sparc-tdep.h"
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/* Signal trampoline support.  */
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static void sparc32_linux_sigframe_init (const struct tramp_frame *self,
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                                         struct frame_info *this_frame,
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                                         struct trad_frame_cache *this_cache,
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                                         CORE_ADDR func);
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/* GNU/Linux has two flavors of signals.  Normal signal handlers, and
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   "realtime" (RT) signals.  The RT signals can provide additional
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   information to the signal handler if the SA_SIGINFO flag is set
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   when establishing a signal handler using `sigaction'.  It is not
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   unlikely that future versions of GNU/Linux will support SA_SIGINFO
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   for normal signals too.  */
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/* When the sparc Linux kernel calls a signal handler and the
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   SA_RESTORER flag isn't set, the return address points to a bit of
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   code on the stack.  This code checks whether the PC appears to be
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   within this bit of code.
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   The instruction sequence for normal signals is encoded below.
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   Checking for the code sequence should be somewhat reliable, because
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   the effect is to call the system call sigreturn.  This is unlikely
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   to occur anywhere other than a signal trampoline.  */
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static const struct tramp_frame sparc32_linux_sigframe =
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{
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  SIGTRAMP_FRAME,
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  4,
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  {
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    { 0x821020d8, -1 },         /* mov __NR_sugreturn, %g1 */
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    { 0x91d02010, -1 },         /* ta  0x10 */
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    { TRAMP_SENTINEL_INSN, -1 }
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  },
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  sparc32_linux_sigframe_init
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};
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/* The instruction sequence for RT signals is slightly different.  The
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   effect is to call the system call rt_sigreturn.  */
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static const struct tramp_frame sparc32_linux_rt_sigframe =
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{
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  SIGTRAMP_FRAME,
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  4,
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  {
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    { 0x82102065, -1 },         /* mov __NR_rt_sigreturn, %g1 */
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    { 0x91d02010, -1 },         /* ta  0x10 */
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    { TRAMP_SENTINEL_INSN, -1 }
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  },
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  sparc32_linux_sigframe_init
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};
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static void
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sparc32_linux_sigframe_init (const struct tramp_frame *self,
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                             struct frame_info *this_frame,
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                             struct trad_frame_cache *this_cache,
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                             CORE_ADDR func)
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{
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  CORE_ADDR base, addr, sp_addr;
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  int regnum;
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  base = get_frame_register_unsigned (this_frame, SPARC_O1_REGNUM);
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  if (self == &sparc32_linux_rt_sigframe)
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    base += 128;
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  /* Offsets from <bits/sigcontext.h>.  */
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  trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0);
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  trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 4);
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  trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 8);
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  trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 12);
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  /* Since %g0 is always zero, keep the identity encoding.  */
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  addr = base + 20;
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  sp_addr = base + 16 + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 4);
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  for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
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    {
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      trad_frame_set_reg_addr (this_cache, regnum, addr);
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      addr += 4;
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    }
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  base = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
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  addr = get_frame_memory_unsigned (this_frame, sp_addr, 4);
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  for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
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    {
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      trad_frame_set_reg_addr (this_cache, regnum, addr);
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      addr += 4;
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    }
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  trad_frame_set_id (this_cache, frame_id_build (base, func));
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}
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/* Return the address of a system call's alternative return
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   address.  */
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static CORE_ADDR
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sparc32_linux_step_trap (struct frame_info *frame, unsigned long insn)
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{
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  if (insn == 0x91d02010)
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    {
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      ULONGEST sc_num = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);
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      /* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216  */
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      if (sc_num == 101 || sc_num == 216)
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        {
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          struct gdbarch *gdbarch = get_frame_arch (frame);
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          enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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          ULONGEST sp, pc_offset;
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          sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);
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          /* The kernel puts the sigreturn registers on the stack,
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             and this is where the signal unwinding state is take from
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             when returning from a signal.
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153
             For __NR_sigreturn, this register area sits 96 bytes from
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             the base of the stack.  The saved PC sits 4 bytes into the
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             sigreturn register save area.
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157
             For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
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             right before the sigreturn register save area.  */
159
 
160
          pc_offset = 96 + 4;
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          if (sc_num == 101)
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            pc_offset += 128;
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          return read_memory_unsigned_integer (sp + pc_offset, 4, byte_order);
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        }
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    }
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  return 0;
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}
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const struct sparc_gregset sparc32_linux_core_gregset =
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{
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  32 * 4,                       /* %psr */
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  33 * 4,                       /* %pc */
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  34 * 4,                       /* %npc */
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  35 * 4,                       /* %y */
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  -1,                           /* %wim */
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  -1,                           /* %tbr */
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  1 * 4,                        /* %g1 */
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  16 * 4,                       /* %l0 */
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  4,                            /* y size */
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};
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static void
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sparc32_linux_supply_core_gregset (const struct regset *regset,
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                                   struct regcache *regcache,
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                                   int regnum, const void *gregs, size_t len)
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{
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  sparc32_supply_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
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}
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static void
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sparc32_linux_collect_core_gregset (const struct regset *regset,
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                                    const struct regcache *regcache,
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                                    int regnum, void *gregs, size_t len)
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{
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  sparc32_collect_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
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}
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static void
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sparc32_linux_supply_core_fpregset (const struct regset *regset,
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                                    struct regcache *regcache,
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                                    int regnum, const void *fpregs, size_t len)
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{
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  sparc32_supply_fpregset (regcache, regnum, fpregs);
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}
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static void
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sparc32_linux_collect_core_fpregset (const struct regset *regset,
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                                     const struct regcache *regcache,
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                                     int regnum, void *fpregs, size_t len)
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{
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  sparc32_collect_fpregset (regcache, regnum, fpregs);
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}
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/* Set the program counter for process PTID to PC.  */
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#define PSR_SYSCALL     0x00004000
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static void
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sparc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
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{
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  struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache));
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  ULONGEST psr;
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  regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc);
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  regcache_cooked_write_unsigned (regcache, tdep->npc_regnum, pc + 4);
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  /* Clear the "in syscall" bit to prevent the kernel from
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     messing with the PCs we just installed, if we happen to be
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     within an interrupted system call that the kernel wants to
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     restart.
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     Note that after we return from the dummy call, the PSR et al.
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     registers will be automatically restored, and the kernel
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     continues to restart the system call at this point.  */
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  regcache_cooked_read_unsigned (regcache, SPARC32_PSR_REGNUM, &psr);
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  psr &= ~PSR_SYSCALL;
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  regcache_cooked_write_unsigned (regcache, SPARC32_PSR_REGNUM, psr);
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}
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static void
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sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
249
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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  tdep->gregset = regset_alloc (gdbarch, sparc32_linux_supply_core_gregset,
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                                sparc32_linux_collect_core_gregset);
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  tdep->sizeof_gregset = 152;
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  tdep->fpregset = regset_alloc (gdbarch, sparc32_linux_supply_core_fpregset,
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                                 sparc32_linux_collect_core_fpregset);
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  tdep->sizeof_fpregset = 396;
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  tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_sigframe);
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  tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_rt_sigframe);
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  /* GNU/Linux has SVR4-style shared libraries...  */
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  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
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  set_solib_svr4_fetch_link_map_offsets
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    (gdbarch, svr4_ilp32_fetch_link_map_offsets);
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267
  /* ...which means that we need some special handling when doing
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     prologue analysis.  */
269
  tdep->plt_entry_size = 12;
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271
  /* Enable TLS support.  */
272
  set_gdbarch_fetch_tls_load_module_address (gdbarch,
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                                             svr4_fetch_objfile_link_map);
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275
  /* Make sure we can single-step over signal return system calls.  */
276
  tdep->step_trap = sparc32_linux_step_trap;
277
 
278
  /* Hook in the DWARF CFI frame unwinder.  */
279
  dwarf2_append_unwinders (gdbarch);
280
 
281
  set_gdbarch_write_pc (gdbarch, sparc_linux_write_pc);
282
}
283
 
284
/* Provide a prototype to silence -Wmissing-prototypes.  */
285
extern void _initialize_sparc_linux_tdep (void);
286
 
287
void
288
_initialize_sparc_linux_tdep (void)
289
{
290
  gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_LINUX,
291
                          sparc32_linux_init_abi);
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}

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