binutils-gdb/gdb/lynx-nat.c

/* Native-dependent code for LynxOS.
   Copyright 1993, 1994 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "frame.h"
#include "inferior.h"
#include "target.h"

#include <sys/ptrace.h>
#include <sys/wait.h>
#include <sys/fpp.h>

static unsigned long registers_addr PARAMS ((int pid));

#define X(ENTRY)(offsetof(struct econtext, ENTRY))

#ifdef I386
/* Mappings from tm-i386v.h */

static int regmap[] =
{
  X(eax),
  X(ecx),
  X(edx),
  X(ebx),
  X(esp),			/* sp */
  X(ebp),			/* fp */
  X(esi),
  X(edi),
  X(eip),			/* pc */
  X(flags),			/* ps */
  X(cs),
  X(ss),
  X(ds),
  X(es),
  X(ecode),			/* Lynx doesn't give us either fs or gs, so */
  X(fault),			/* we just substitute these two in the hopes
				   that they are useful. */
};
#endif /* I386 */

#ifdef M68K
/* Mappings from tm-m68k.h */

static int regmap[] =
{
  X(regs[0]),			/* d0 */
  X(regs[1]),			/* d1 */
  X(regs[2]),			/* d2 */
  X(regs[3]),			/* d3 */
  X(regs[4]),			/* d4 */
  X(regs[5]),			/* d5 */
  X(regs[6]),			/* d6 */
  X(regs[7]),			/* d7 */
  X(regs[8]),			/* a0 */
  X(regs[9]),			/* a1 */
  X(regs[10]),			/* a2 */
  X(regs[11]),			/* a3 */
  X(regs[12]),			/* a4 */
  X(regs[13]),			/* a5 */
  X(regs[14]),			/* fp */
  offsetof (st_t, usp) - offsetof (st_t, ec), /* sp */
  X(status),			/* ps */
  X(pc),

  X(fregs[0*3]),		/* fp0 */
  X(fregs[1*3]),		/* fp1 */
  X(fregs[2*3]),		/* fp2 */
  X(fregs[3*3]),		/* fp3 */
  X(fregs[4*3]),		/* fp4 */
  X(fregs[5*3]),		/* fp5 */
  X(fregs[6*3]),		/* fp6 */
  X(fregs[7*3]),		/* fp7 */

  X(fcregs[0]),			/* fpcontrol */
  X(fcregs[1]),			/* fpstatus */
  X(fcregs[2]),			/* fpiaddr */
  X(ssw),			/* fpcode */
  X(fault),			/* fpflags */
};
#endif /* M68K */

#ifdef SPARC
/* Mappings from tm-sparc.h */

#define FX(ENTRY)(offsetof(struct fcontext, ENTRY))

static int regmap[] =
{
  -1,				/* g0 */
  X(g1),
  X(g2),
  X(g3),
  X(g4),
  -1,				/* g5->g7 aren't saved by Lynx */
  -1,
  -1,

  X(o[0]),
  X(o[1]),
  X(o[2]),
  X(o[3]),
  X(o[4]),
  X(o[5]),
  X(o[6]),			/* sp */
  X(o[7]),			/* ra */

  -1,-1,-1,-1,-1,-1,-1,-1,	/* l0 -> l7 */

  -1,-1,-1,-1,-1,-1,-1,-1,	/* i0 -> i7 */

  FX(f.fregs[0]),		/* f0 */
  FX(f.fregs[1]),
  FX(f.fregs[2]),
  FX(f.fregs[3]),
  FX(f.fregs[4]),
  FX(f.fregs[5]),
  FX(f.fregs[6]),
  FX(f.fregs[7]),
  FX(f.fregs[8]),
  FX(f.fregs[9]),
  FX(f.fregs[10]),
  FX(f.fregs[11]),
  FX(f.fregs[12]),
  FX(f.fregs[13]),
  FX(f.fregs[14]),
  FX(f.fregs[15]),
  FX(f.fregs[16]),
  FX(f.fregs[17]),
  FX(f.fregs[18]),
  FX(f.fregs[19]),
  FX(f.fregs[20]),
  FX(f.fregs[21]),
  FX(f.fregs[22]),
  FX(f.fregs[23]),
  FX(f.fregs[24]),
  FX(f.fregs[25]),
  FX(f.fregs[26]),
  FX(f.fregs[27]),
  FX(f.fregs[28]),
  FX(f.fregs[29]),
  FX(f.fregs[30]),
  FX(f.fregs[31]),

  X(y),
  X(psr),
  X(wim),
  X(tbr),
  X(pc),
  X(npc),
  FX(fsr),			/* fpsr */
  -1,				/* cpsr */
};
#endif /* SPARC */

#ifdef rs6000

static int regmap[] =
{
  X(iregs[0]),			/* r0 */
  X(iregs[1]),
  X(iregs[2]),
  X(iregs[3]),
  X(iregs[4]),
  X(iregs[5]),
  X(iregs[6]),
  X(iregs[7]),
  X(iregs[8]),
  X(iregs[9]),
  X(iregs[10]),
  X(iregs[11]),
  X(iregs[12]),
  X(iregs[13]),
  X(iregs[14]),
  X(iregs[15]),
  X(iregs[16]),
  X(iregs[17]),
  X(iregs[18]),
  X(iregs[19]),
  X(iregs[20]),
  X(iregs[21]),
  X(iregs[22]),
  X(iregs[23]),
  X(iregs[24]),
  X(iregs[25]),
  X(iregs[26]),
  X(iregs[27]),
  X(iregs[28]),
  X(iregs[29]),
  X(iregs[30]),
  X(iregs[31]),

  X(fregs[0]),			/* f0 */
  X(fregs[1]),
  X(fregs[2]),
  X(fregs[3]),
  X(fregs[4]),
  X(fregs[5]),
  X(fregs[6]),
  X(fregs[7]),
  X(fregs[8]),
  X(fregs[9]),
  X(fregs[10]),
  X(fregs[11]),
  X(fregs[12]),
  X(fregs[13]),
  X(fregs[14]),
  X(fregs[15]),
  X(fregs[16]),
  X(fregs[17]),
  X(fregs[18]),
  X(fregs[19]),
  X(fregs[20]),
  X(fregs[21]),
  X(fregs[22]),
  X(fregs[23]),
  X(fregs[24]),
  X(fregs[25]),
  X(fregs[26]),
  X(fregs[27]),
  X(fregs[28]),
  X(fregs[29]),
  X(fregs[30]),
  X(fregs[31]),

  X(srr0),			/* IAR (PC) */
  X(srr1),			/* MSR (PS) */
  X(cr),			/* CR */
  X(lr),			/* LR */
  X(ctr),			/* CTR */
  X(xer),			/* XER */
  X(mq)				/* MQ */
};

#endif /* rs6000 */

#ifdef SPARC

/* This routine handles some oddball cases for Sparc registers and LynxOS.
   In partucular, it causes refs to G0, g5->7, and all fp regs to return zero.
   It also handles knows where to find the I & L regs on the stack.  */

void
fetch_inferior_registers (regno)
     int regno;
{
  int whatregs = 0;

#define WHATREGS_FLOAT 1
#define WHATREGS_GEN 2
#define WHATREGS_STACK 4

  if (regno == -1)
    whatregs = WHATREGS_FLOAT | WHATREGS_GEN | WHATREGS_STACK;
  else if (regno >= L0_REGNUM && regno <= I7_REGNUM)
    whatregs = WHATREGS_STACK;
  else if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 32)
    whatregs = WHATREGS_FLOAT;
  else
    whatregs = WHATREGS_GEN;

  if (whatregs & WHATREGS_GEN)
    {
      struct econtext ec;		/* general regs */
      char buf[MAX_REGISTER_RAW_SIZE];
      int retval;
      int i;

      errno = 0;
      retval = ptrace (PTRACE_GETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &ec,
		       0);
      if (errno)
	perror_with_name ("ptrace(PTRACE_GETREGS)");
  
      memset (buf, 0, REGISTER_RAW_SIZE (G0_REGNUM));
      supply_register (G0_REGNUM, buf);
      supply_register (TBR_REGNUM, (char *)&ec.tbr);

      memcpy (&registers[REGISTER_BYTE (G1_REGNUM)], &ec.g1,
	      4 * REGISTER_RAW_SIZE (G1_REGNUM));
      for (i = G1_REGNUM; i <= G1_REGNUM + 3; i++)
	register_valid[i] = 1;

      supply_register (PS_REGNUM, (char *)&ec.psr);
      supply_register (Y_REGNUM, (char *)&ec.y);
      supply_register (PC_REGNUM, (char *)&ec.pc);
      supply_register (NPC_REGNUM, (char *)&ec.npc);
      supply_register (WIM_REGNUM, (char *)&ec.wim);

      memcpy (&registers[REGISTER_BYTE (O0_REGNUM)], ec.o,
	      8 * REGISTER_RAW_SIZE (O0_REGNUM));
      for (i = O0_REGNUM; i <= O0_REGNUM + 7; i++)
	register_valid[i] = 1;
    }

  if (whatregs & WHATREGS_STACK)
    {
      CORE_ADDR sp;
      int i;

      sp = read_register (SP_REGNUM);

      target_xfer_memory (sp + FRAME_SAVED_I0,
			  &registers[REGISTER_BYTE(I0_REGNUM)],
			  8 * REGISTER_RAW_SIZE (I0_REGNUM), 0);
      for (i = I0_REGNUM; i <= I7_REGNUM; i++)
	register_valid[i] = 1;

      target_xfer_memory (sp + FRAME_SAVED_L0,
			  &registers[REGISTER_BYTE(L0_REGNUM)],
			  8 * REGISTER_RAW_SIZE (L0_REGNUM), 0);
      for (i = L0_REGNUM; i <= L0_REGNUM + 7; i++)
	register_valid[i] = 1;
    }

  if (whatregs & WHATREGS_FLOAT)
    {
      struct fcontext fc;		/* fp regs */
      int retval;
      int i;

      errno = 0;
      retval = ptrace (PTRACE_GETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
		       0);
      if (errno)
	perror_with_name ("ptrace(PTRACE_GETFPREGS)");
  
      memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], fc.f.fregs,
	      32 * REGISTER_RAW_SIZE (FP0_REGNUM));
      for (i = FP0_REGNUM; i <= FP0_REGNUM + 31; i++)
	register_valid[i] = 1;

      supply_register (FPS_REGNUM, (char *)&fc.fsr);
    }
}

/* This routine handles storing of the I & L regs for the Sparc.  The trick
   here is that they actually live on the stack.  The really tricky part is
   that when changing the stack pointer, the I & L regs must be written to
   where the new SP points, otherwise the regs will be incorrect when the
   process is started up again.   We assume that the I & L regs are valid at
   this point.  */

void
store_inferior_registers (regno)
     int regno;
{
  int whatregs = 0;

  if (regno == -1)
    whatregs = WHATREGS_FLOAT | WHATREGS_GEN | WHATREGS_STACK;
  else if (regno >= L0_REGNUM && regno <= I7_REGNUM)
    whatregs = WHATREGS_STACK;
  else if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 32)
    whatregs = WHATREGS_FLOAT;
  else if (regno == SP_REGNUM)
    whatregs = WHATREGS_STACK | WHATREGS_GEN;
  else
    whatregs = WHATREGS_GEN;

  if (whatregs & WHATREGS_GEN)
    {
      struct econtext ec;		/* general regs */
      int retval;

      ec.tbr = read_register (TBR_REGNUM);
      memcpy (&ec.g1, &registers[REGISTER_BYTE (G1_REGNUM)],
	      4 * REGISTER_RAW_SIZE (G1_REGNUM));

      ec.psr = read_register (PS_REGNUM);
      ec.y = read_register (Y_REGNUM);
      ec.pc = read_register (PC_REGNUM);
      ec.npc = read_register (NPC_REGNUM);
      ec.wim = read_register (WIM_REGNUM);

      memcpy (ec.o, &registers[REGISTER_BYTE (O0_REGNUM)],
	      8 * REGISTER_RAW_SIZE (O0_REGNUM));

      errno = 0;
      retval = ptrace (PTRACE_SETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &ec,
		       0);
      if (errno)
	perror_with_name ("ptrace(PTRACE_SETREGS)");
    }

  if (whatregs & WHATREGS_STACK)
    {
      int regoffset;
      CORE_ADDR sp;

      sp = read_register (SP_REGNUM);

      if (regno == -1 || regno == SP_REGNUM)
	{
	  if (!register_valid[L0_REGNUM+5])
	    abort();
	  target_xfer_memory (sp + FRAME_SAVED_I0,
			      &registers[REGISTER_BYTE (I0_REGNUM)],
			      8 * REGISTER_RAW_SIZE (I0_REGNUM), 1);

	  target_xfer_memory (sp + FRAME_SAVED_L0,
			      &registers[REGISTER_BYTE (L0_REGNUM)],
			      8 * REGISTER_RAW_SIZE (L0_REGNUM), 1);
	}
      else if (regno >= L0_REGNUM && regno <= I7_REGNUM)
	{
	  if (!register_valid[regno])
	    abort();
	  if (regno >= L0_REGNUM && regno <= L0_REGNUM + 7)
	    regoffset = REGISTER_BYTE (regno) - REGISTER_BYTE (L0_REGNUM)
	      + FRAME_SAVED_L0;
	  else
	    regoffset = REGISTER_BYTE (regno) - REGISTER_BYTE (I0_REGNUM)
	      + FRAME_SAVED_I0;
	  target_xfer_memory (sp + regoffset, &registers[REGISTER_BYTE (regno)],
			      REGISTER_RAW_SIZE (regno), 1);
	}
    }

  if (whatregs & WHATREGS_FLOAT)
    {
      struct fcontext fc;		/* fp regs */
      int retval;

/* We read fcontext first so that we can get good values for fq_t... */
      errno = 0;
      retval = ptrace (PTRACE_GETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
		       0);
      if (errno)
	perror_with_name ("ptrace(PTRACE_GETFPREGS)");
  
      memcpy (fc.f.fregs, &registers[REGISTER_BYTE (FP0_REGNUM)],
	      32 * REGISTER_RAW_SIZE (FP0_REGNUM));

      fc.fsr = read_register (FPS_REGNUM);

      errno = 0;
      retval = ptrace (PTRACE_SETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
		       0);
      if (errno)
	perror_with_name ("ptrace(PTRACE_SETFPREGS)");
      }
}
#endif /* SPARC */

#if defined (I386) || defined (M68K) || defined (rs6000)

/* Return the offset relative to the start of the per-thread data to the
   saved context block.  */

static unsigned long
registers_addr(pid)
     int pid;
{
  CORE_ADDR stblock;
  int ecpoff = offsetof(st_t, ecp);
  CORE_ADDR ecp;

  errno = 0;
  stblock = (CORE_ADDR) ptrace (PTRACE_THREADUSER, pid, (PTRACE_ARG3_TYPE)0,
				0);
  if (errno)
    perror_with_name ("ptrace(PTRACE_THREADUSER)");

  ecp = (CORE_ADDR) ptrace (PTRACE_PEEKTHREAD, pid, (PTRACE_ARG3_TYPE)ecpoff,
			    0);
  if (errno)
    perror_with_name ("ptrace(PTRACE_PEEKTHREAD)");

  return ecp - stblock;
}

/* 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 (regno)
     int regno;
{
  int reglo, reghi;
  int i;
  unsigned long ecp;

  if (regno == -1)
    {
      reglo = 0;
      reghi = NUM_REGS - 1;
    }
  else
    reglo = reghi = regno;

  ecp = registers_addr (inferior_pid);

  for (regno = reglo; regno <= reghi; regno++)
    {
      char buf[MAX_REGISTER_RAW_SIZE];
      int ptrace_fun = PTRACE_PEEKTHREAD;

#ifdef M68K
      ptrace_fun = regno == SP_REGNUM ? PTRACE_PEEKUSP : PTRACE_PEEKTHREAD;
#endif

      for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
	{
	  unsigned int reg;

	  errno = 0;
	  reg = ptrace (ptrace_fun, inferior_pid,
			(PTRACE_ARG3_TYPE) (ecp + regmap[regno] + i), 0);
	  if (errno)
	    perror_with_name ("ptrace(PTRACE_PEEKUSP)");
  
	  *(int *)&buf[i] = reg;
	}
      supply_register (regno, buf);
    }
}

/* 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).  */

/* Registers we shouldn't try to store.  */
#if !defined (CANNOT_STORE_REGISTER)
#define CANNOT_STORE_REGISTER(regno) 0
#endif

void
store_inferior_registers (regno)
     int regno;
{
  int reglo, reghi;
  int i;
  unsigned long ecp;

  if (regno == -1)
    {
      reglo = 0;
      reghi = NUM_REGS - 1;
    }
  else
    reglo = reghi = regno;

  ecp = registers_addr (inferior_pid);

  for (regno = reglo; regno <= reghi; regno++)
    {
      int ptrace_fun = PTRACE_POKEUSER;

      if (CANNOT_STORE_REGISTER (regno))
	continue;

#ifdef M68K
      ptrace_fun = regno == SP_REGNUM ? PTRACE_POKEUSP : PTRACE_POKEUSER;
#endif

      for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
	{
	  unsigned int reg;

	  reg = *(unsigned int *)&registers[REGISTER_BYTE (regno) + i];

	  errno = 0;
	  ptrace (ptrace_fun, inferior_pid,
		  (PTRACE_ARG3_TYPE) (ecp + regmap[regno] + i), reg);
	  if (errno)
	    perror_with_name ("ptrace(PTRACE_POKEUSP)");
	}
    }
}
#endif /* defined (I386) || defined (M68K) || defined (rs6000) */

/* Wait for child to do something.  Return pid of child, or -1 in case
   of error; store status through argument pointer OURSTATUS.  */

int
child_wait (pid, ourstatus)
     int pid;
     struct target_waitstatus *ourstatus;
{
  int save_errno;
  int thread;
  union wait status;

  while (1)
    {
      int sig;

      set_sigint_trap();	/* Causes SIGINT to be passed on to the
				   attached process. */
      pid = wait (&status);

      save_errno = errno;

      clear_sigint_trap();

      if (pid == -1)
	{
	  if (save_errno == EINTR)
	    continue;
	  fprintf_unfiltered (gdb_stderr, "Child process unexpectedly missing: %s.\n",
		   safe_strerror (save_errno));
	  /* Claim it exited with unknown signal.  */
	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
	  ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
	  return -1;
	}

      if (pid != PIDGET (inferior_pid))	/* Some other process?!? */
	continue;

      thread = status.w_tid;	/* Get thread id from status */

      /* Initial thread value can only be acquired via wait, so we have to
	 resort to this hack.  */

      if (TIDGET (inferior_pid) == 0)
	{
	  inferior_pid = BUILDPID (inferior_pid, thread);
	  add_thread (inferior_pid);
	}

      pid = BUILDPID (pid, thread);

      if (WIFSTOPPED(status)
	  && WSTOPSIG(status) == SIGTRAP
	  && !in_thread_list (pid))
	{
	  int realsig;

	  realsig = ptrace (PTRACE_GETTRACESIG, pid, (PTRACE_ARG3_TYPE)0, 0);

	  if (realsig == SIGNEWTHREAD)
	    {
	      /* Simply ignore new thread notification, as we can't do anything
		 useful with such threads.  All ptrace calls at this point just
		 fail for no apparent reason.  The thread will eventually get a
		 real signal when it becomes real.  */
	      child_resume (pid, 0, TARGET_SIGNAL_0);
	      continue;
	    }
	}

#ifdef SPARC
      /* SPARC Lynx uses an byte reversed wait status; we must use the
	 host macros to access it.  These lines just a copy of
	 store_waitstatus.  We can't use CHILD_SPECIAL_WAITSTATUS
	 because target.c can't include the Lynx <sys/wait.h>.  */
      if (WIFEXITED (status))
	{
	  ourstatus->kind = TARGET_WAITKIND_EXITED;
	  ourstatus->value.integer = WEXITSTATUS (status);
	}
      else if (!WIFSTOPPED (status))
	{
	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
	  ourstatus->value.sig =
	    target_signal_from_host (WTERMSIG (status));
	}
      else
	{
	  ourstatus->kind = TARGET_WAITKIND_STOPPED;
	  ourstatus->value.sig =
	    target_signal_from_host (WSTOPSIG (status));
	}
#else
      store_waitstatus (ourstatus, status.w_status);
#endif

      return pid;
    }
}

/* Resume execution of the inferior process.
   If STEP is nonzero, single-step it.
   If SIGNAL is nonzero, give it that signal.  */

void
child_resume (pid, step, signal)
     int pid;
     int step;
     enum target_signal signal;
{
  int func;

  errno = 0;

  if (pid == -1)
    {
      /* Resume all threads.  */

      pid = inferior_pid;
    }

  func = step ? PTRACE_SINGLESTEP_ONE : PTRACE_CONT;

  /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where
     it was.  (If GDB wanted it to start some other way, we have already
     written a new PC value to the child.)

     If this system does not support PT_STEP, a higher level function will
     have called single_step() to transmute the step request into a
     continue request (by setting breakpoints on all possible successor
     instructions), so we don't have to worry about that here.  */

  ptrace (func, pid, (PTRACE_ARG3_TYPE) 1, target_signal_to_host (signal));

  if (errno)
    perror_with_name ("ptrace");
}

/* Convert a Lynx process ID to a string.  Returns the string in a static
   buffer.  */

char *
lynx_pid_to_str (pid)
     int pid;
{
  static char buf[40];

  sprintf (buf, "process %d thread %d", PIDGET (pid), TIDGET (pid));

  return buf;
}

/* Extract the register values out of the core file and store
   them where `read_register' will find them.

   CORE_REG_SECT points to the register values themselves, read into memory.
   CORE_REG_SIZE is the size of that area.
   WHICH says which set of registers we are handling (0 = int, 2 = float
         on machines where they are discontiguous).
   REG_ADDR is the offset from u.u_ar0 to the register values relative to
            core_reg_sect.  This is used with old-fashioned core files to
	    locate the registers in a large upage-plus-stack ".reg" section.
	    Original upage address X is at location core_reg_sect+x+reg_addr.
 */

void
fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
     char *core_reg_sect;
     unsigned core_reg_size;
     int which;
     unsigned reg_addr;
{
  struct st_entry s;
  unsigned int regno;

  for (regno = 0; regno < NUM_REGS; regno++)
    if (regmap[regno] != -1)
      supply_register (regno, core_reg_sect + offsetof (st_t, ec)
		       + regmap[regno]);

#ifdef SPARC
/* Fetching this register causes all of the I & L regs to be read from the
   stack and validated.  */

  fetch_inferior_registers (I0_REGNUM);
#endif
}