sparc-nat.c   [plain text]

/* Functions specific to running gdb native on a SPARC running SunOS4.
   Copyright 1989, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000, 2001,
   2002
   Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "inferior.h"
#include "target.h"
#include "gdbcore.h"
#include "regcache.h"

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#include <signal.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#ifdef __linux__
#include <asm/reg.h>
#else
#include <machine/reg.h>
#endif
#include <sys/user.h>

/* We don't store all registers immediately when requested, since they
   get sent over in large chunks anyway.  Instead, we accumulate most
   of the changes and send them over once.  "deferred_stores" keeps
   track of which sets of registers we have locally-changed copies of,
   so we only need send the groups that have changed.  */

#define	INT_REGS	1
#define	STACK_REGS	2
#define	FP_REGS		4

/* Fetch one or more registers from the inferior.  REGNO == -1 to get
   them all.  We actually fetch more than requested, when convenient,
   marking them as valid so we won't fetch them again.  */

void
fetch_inferior_registers (int regno)
{
  struct regs inferior_registers;
  struct fp_status inferior_fp_registers;
  int i;
  int fetch_pid;

  /* NOTE: cagney/2002-12-03: This code assumes that the currently
     selected light weight processes' registers can be written
     directly into the selected thread's register cache.  This works
     fine when given an 1:1 LWP:thread model (such as found on
     GNU/Linux) but will, likely, have problems when used on an N:1
     (userland threads) or N:M (userland multiple LWP) model.  In the
     case of the latter two, the LWP's registers do not necessarily
     belong to the selected thread (the LWP could be in the middle of
     executing the thread switch code).

     These functions should instead be paramaterized with an explicit
     object (struct regcache, struct thread_info?) into which the LWPs
     registers can be written.  */

  fetch_pid = TIDGET (inferior_ptid);
  if (fetch_pid == 0)
    fetch_pid = PIDGET (inferior_ptid);

  /* We should never be called with deferred stores, because a prerequisite
     for writing regs is to have fetched them all (PREPARE_TO_STORE), sigh.  */
  if (deferred_stores)
    internal_error (__FILE__, __LINE__, "failed internal consistency check");

  DO_DEFERRED_STORES;

  /* Global and Out regs are fetched directly, as well as the control
     registers.  If we're getting one of the in or local regs,
     and the stack pointer has not yet been fetched,
     we have to do that first, since they're found in memory relative
     to the stack pointer.  */
  if (regno < O7_REGNUM		/* including -1 */
      || regno >= Y_REGNUM
      || (!deprecated_register_valid[SP_REGNUM] && regno < I7_REGNUM))
    {
      if (0 != ptrace (PTRACE_GETREGS, fetch_pid,
		       (PTRACE_ARG3_TYPE) & inferior_registers, 0))
	perror ("ptrace_getregs");

      deprecated_registers[REGISTER_BYTE (0)] = 0;
      memcpy (&deprecated_registers[REGISTER_BYTE (1)],
	      &inferior_registers.r_g1, 15 * REGISTER_RAW_SIZE (G0_REGNUM));
      *(int *) &deprecated_registers[REGISTER_BYTE (PS_REGNUM)]
	= inferior_registers.r_ps;
      *(int *) &deprecated_registers[REGISTER_BYTE (PC_REGNUM)]
	= inferior_registers.r_pc;
      *(int *) &deprecated_registers[REGISTER_BYTE (NPC_REGNUM)]
	= inferior_registers.r_npc;
      *(int *) &registers[REGISTER_BYTE (Y_REGNUM)] = inferior_registers.r_y;

      for (i = G0_REGNUM; i <= O7_REGNUM; i++)
	deprecated_register_valid[i] = 1;
      deprecated_register_valid[Y_REGNUM] = 1;
      deprecated_register_valid[PS_REGNUM] = 1;
      deprecated_register_valid[PC_REGNUM] = 1;
      deprecated_register_valid[NPC_REGNUM] = 1;
      /* If we don't set these valid, read_register_bytes() rereads
         all the regs every time it is called!  FIXME.  */
      deprecated_register_valid[WIM_REGNUM] = 1;	/* Not true yet, FIXME */
      deprecated_register_valid[TBR_REGNUM] = 1;	/* Not true yet, FIXME */
      deprecated_register_valid[CPS_REGNUM] = 1;	/* Not true yet, FIXME */
    }

  /* Floating point registers */
  if (regno == -1 ||
      regno == FPS_REGNUM ||
      (regno >= FP0_REGNUM && regno <= FP0_REGNUM + 31))
    {
      if (0 != ptrace (PTRACE_GETFPREGS, fetch_pid,
		       (PTRACE_ARG3_TYPE) & inferior_fp_registers,
		       0))
	perror ("ptrace_getfpregs");
      memcpy (&deprecated_registers[REGISTER_BYTE (FP0_REGNUM)],
	      &inferior_fp_registers, sizeof inferior_fp_registers.fpu_fr);
      memcpy (&deprecated_registers[REGISTER_BYTE (FPS_REGNUM)],
	      &inferior_fp_registers.Fpu_fsr, sizeof (FPU_FSR_TYPE));
      for (i = FP0_REGNUM; i <= FP0_REGNUM + 31; i++)
	deprecated_register_valid[i] = 1;
      deprecated_register_valid[FPS_REGNUM] = 1;
    }

  /* These regs are saved on the stack by the kernel.  Only read them
     all (16 ptrace calls!) if we really need them.  */
  if (regno == -1)
    {
      CORE_ADDR sp = *(unsigned int *) & deprecated_registers[REGISTER_BYTE (SP_REGNUM)];
      target_read_memory (sp, &deprecated_registers[REGISTER_BYTE (L0_REGNUM)],
			  16 * REGISTER_RAW_SIZE (L0_REGNUM));
      for (i = L0_REGNUM; i <= I7_REGNUM; i++)
	deprecated_register_valid[i] = 1;
    }
  else if (regno >= L0_REGNUM && regno <= I7_REGNUM)
    {
      CORE_ADDR sp = *(unsigned int *) & deprecated_registers[REGISTER_BYTE (SP_REGNUM)];
      i = REGISTER_BYTE (regno);
      if (deprecated_register_valid[regno])
	printf_unfiltered ("register %d valid and read\n", regno);
      target_read_memory (sp + i - REGISTER_BYTE (L0_REGNUM),
			  &deprecated_registers[i], REGISTER_RAW_SIZE (regno));
      deprecated_register_valid[regno] = 1;
    }
}

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

void
store_inferior_registers (int regno)
{
  struct regs inferior_registers;
  struct fp_status inferior_fp_registers;
  int wanna_store = INT_REGS + STACK_REGS + FP_REGS;
  int store_pid;

  /* NOTE: cagney/2002-12-02: See comment in fetch_inferior_registers
     about threaded assumptions.  */
  store_pid = TIDGET (inferior_ptid);
  if (store_pid == 0)
    store_pid = PIDGET (inferior_ptid);

  /* First decide which pieces of machine-state we need to modify.  
     Default for regno == -1 case is all pieces.  */
  if (regno >= 0)
    {
      if (FP0_REGNUM <= regno && regno < FP0_REGNUM + 32)
	{
	  wanna_store = FP_REGS;
	}
      else
	{
	  if (regno == SP_REGNUM)
	    wanna_store = INT_REGS + STACK_REGS;
	  else if (regno < L0_REGNUM || regno > I7_REGNUM)
	    wanna_store = INT_REGS;
	  else if (regno == FPS_REGNUM)
	    wanna_store = FP_REGS;
	  else
	    wanna_store = STACK_REGS;
	}
    }

  /* See if we're forcing the stores to happen now, or deferring. */
  if (regno == -2)
    {
      wanna_store = deferred_stores;
      deferred_stores = 0;
    }
  else
    {
      if (wanna_store == STACK_REGS)
	{
	  /* Fall through and just store one stack reg.  If we deferred
	     it, we'd have to store them all, or remember more info.  */
	}
      else
	{
	  deferred_stores |= wanna_store;
	  return;
	}
    }

  if (wanna_store & STACK_REGS)
    {
      CORE_ADDR sp = *(unsigned int *) & deprecated_registers[REGISTER_BYTE (SP_REGNUM)];

      if (regno < 0 || regno == SP_REGNUM)
	{
	  if (!deprecated_register_valid[L0_REGNUM + 5])
	    internal_error (__FILE__, __LINE__, "failed internal consistency check");
	  target_write_memory (sp,
			       &deprecated_registers[REGISTER_BYTE (L0_REGNUM)],
			       16 * REGISTER_RAW_SIZE (L0_REGNUM));
	}
      else
	{
	  if (!deprecated_register_valid[regno])
	    internal_error (__FILE__, __LINE__, "failed internal consistency check");
	  target_write_memory (sp + REGISTER_BYTE (regno) - REGISTER_BYTE (L0_REGNUM),
			       &deprecated_registers[REGISTER_BYTE (regno)],
			       REGISTER_RAW_SIZE (regno));
	}

    }

  if (wanna_store & INT_REGS)
    {
      if (!deprecated_register_valid[G1_REGNUM])
	internal_error (__FILE__, __LINE__, "failed internal consistency check");

      memcpy (&inferior_registers.r_g1,
	      &deprecated_registers[REGISTER_BYTE (G1_REGNUM)],
	      15 * REGISTER_RAW_SIZE (G1_REGNUM));

      inferior_registers.r_ps =
	*(int *) &deprecated_registers[REGISTER_BYTE (PS_REGNUM)];
      inferior_registers.r_pc =
	*(int *) &deprecated_registers[REGISTER_BYTE (PC_REGNUM)];
      inferior_registers.r_npc =
	*(int *) &deprecated_registers[REGISTER_BYTE (NPC_REGNUM)];
      inferior_registers.r_y =
	*(int *) &deprecated_registers[REGISTER_BYTE (Y_REGNUM)];

      if (0 != ptrace (PTRACE_SETREGS, store_pid,
		       (PTRACE_ARG3_TYPE) & inferior_registers, 0))
	perror ("ptrace_setregs");
    }

  if (wanna_store & FP_REGS)
    {
      if (!deprecated_register_valid[FP0_REGNUM + 9])
	internal_error (__FILE__, __LINE__, "failed internal consistency check");
      memcpy (&inferior_fp_registers,
	      &deprecated_registers[REGISTER_BYTE (FP0_REGNUM)],
	      sizeof inferior_fp_registers.fpu_fr);
      memcpy (&inferior_fp_registers.Fpu_fsr,
	      &deprecated_registers[REGISTER_BYTE (FPS_REGNUM)],
	      sizeof (FPU_FSR_TYPE));
      if (0 !=
	  ptrace (PTRACE_SETFPREGS, store_pid,
		  (PTRACE_ARG3_TYPE) & inferior_fp_registers, 0))
	perror ("ptrace_setfpregs");
    }
}

/* Provide registers to GDB from a core file.

   CORE_REG_SECT points to an array of bytes, which are the contents
   of a `note' from a core file which BFD thinks might contain
   register contents.  CORE_REG_SIZE is its size.

   WHICH says which register set corelow suspects this is:
     0 --- the general-purpose register set
     2 --- the floating-point register set

   IGNORE is unused.  */

static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
		      int which, CORE_ADDR ignore)
{

  if (which == 0)
    {

      /* Integer registers */

#define gregs ((struct regs *)core_reg_sect)
      /* G0 *always* holds 0.  */
      *(int *) &deprecated_registers[REGISTER_BYTE (0)] = 0;

      /* The globals and output registers.  */
      memcpy (&deprecated_registers[REGISTER_BYTE (G1_REGNUM)], &gregs->r_g1,
	      15 * REGISTER_RAW_SIZE (G1_REGNUM));
      *(int *) &deprecated_registers[REGISTER_BYTE (PS_REGNUM)] = gregs->r_ps;
      *(int *) &deprecated_registers[REGISTER_BYTE (PC_REGNUM)] = gregs->r_pc;
      *(int *) &deprecated_registers[REGISTER_BYTE (NPC_REGNUM)] = gregs->r_npc;
      *(int *) &deprecated_registers[REGISTER_BYTE (Y_REGNUM)] = gregs->r_y;

      /* My best guess at where to get the locals and input
         registers is exactly where they usually are, right above
         the stack pointer.  If the core dump was caused by a bus error
         from blowing away the stack pointer (as is possible) then this
         won't work, but it's worth the try. */
      {
	int sp;

	sp = *(int *) &deprecated_registers[REGISTER_BYTE (SP_REGNUM)];
	if (0 != target_read_memory (sp,
				     &deprecated_registers[REGISTER_BYTE (L0_REGNUM)],
				     16 * REGISTER_RAW_SIZE (L0_REGNUM)))
	  {
	    /* fprintf_unfiltered so user can still use gdb */
	    fprintf_unfiltered (gdb_stderr,
		"Couldn't read input and local registers from core file\n");
	  }
      }
    }
  else if (which == 2)
    {

      /* Floating point registers */

#define fpuregs  ((struct fpu *) core_reg_sect)
      if (core_reg_size >= sizeof (struct fpu))
	{
	  memcpy (&deprecated_registers[REGISTER_BYTE (FP0_REGNUM)],
		  fpuregs->fpu_regs, sizeof (fpuregs->fpu_regs));
	  memcpy (&deprecated_registers[REGISTER_BYTE (FPS_REGNUM)],
		  &fpuregs->fpu_fsr, sizeof (FPU_FSR_TYPE));
	}
      else
	fprintf_unfiltered (gdb_stderr, "Couldn't read float regs from core file\n");
    }
}

int
kernel_u_size (void)
{
  return (sizeof (struct user));
}


/* Register that we are able to handle sparc core file formats.
   FIXME: is this really bfd_target_unknown_flavour? */

static struct core_fns sparc_core_fns =
{
  bfd_target_unknown_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_core_registers,			/* core_read_registers */
  NULL					/* next */
};

void
_initialize_core_sparc (void)
{
  add_core_fns (&sparc_core_fns);
}