procfs.c

早期freebsd实现

LOCAL FUNCTION

	procfs_resume -- resume execution of the inferior process

SYNOPSIS

	void procfs_resume (int step, int signo)

DESCRIPTION

	Resume execution of the inferior process.  If STEP is nozero, then
	just single step it.  If SIGNAL is nonzero, restart it with that
	signal activated.

NOTE

	It may not be absolutely necessary to specify the PC value for
	restarting, but to be safe we use the value that gdb considers
	to be current.  One case where this might be necessary is if the
	user explicitly changes the PC value that gdb considers to be
	current.  FIXME:  Investigate if this is necessary or not.

	When attaching to a child process, if we forced it to stop with
	a PIOCSTOP, then we will have set the nopass_next_sigstop flag.
	Upon resuming the first time after such a stop, we explicitly
	inhibit sending it another SIGSTOP, which would be the normal
	result of default signal handling.  One potential drawback to
	this is that we will also ignore any attempt to by the user
	to explicitly continue after the attach with a SIGSTOP.  Ultimately
	this problem should be dealt with by making the routines that
	deal with the inferior a little smarter, and possibly even allow
	an inferior to continue running at the same time as gdb.  (FIXME?)
 */

static void
procfs_resume (step, signo)
     int step;
     int signo;
{
  errno = 0;
  pi.prrun.pr_flags = PRSTRACE | PRSFAULT | PRCFAULT;

#ifdef PRSVADDR_BROKEN
/* Can't do this under Solaris running on a Sparc, as there seems to be no
   place to put nPC.  In fact, if you use this, nPC seems to be set to some
   random garbage.  We have to rely on the fact that PC and nPC have been
   written previously via PIOCSREG during a register flush. */

  pi.prrun.pr_vaddr = (caddr_t) *(int *) &registers[REGISTER_BYTE (PC_REGNUM)];
  pi.prrun.pr_flags != PRSVADDR;
#endif

  if (signo && !(signo == SIGSTOP && pi.nopass_next_sigstop))
    {
      set_proc_siginfo (&pi, signo);
    }
  else
    {
      pi.prrun.pr_flags |= PRCSIG;
    }
  pi.nopass_next_sigstop = 0;
  if (step)
    {
      pi.prrun.pr_flags |= PRSTEP;
    }
  if (ioctl (pi.fd, PIOCRUN, &pi.prrun) != 0)
    {
      perror_with_name (pi.pathname);
      /* NOTREACHED */
    }
}

/*

LOCAL FUNCTION

	procfs_fetch_registers -- fetch current registers from inferior

SYNOPSIS

	void procfs_fetch_registers (int regno)

DESCRIPTION

	Read the current values of the inferior's registers, both the
	general register set and floating point registers (if supported)
	and update gdb's idea of their current values.

*/

static void
procfs_fetch_registers (regno)
     int regno;
{
  if (ioctl (pi.fd, PIOCGREG, &pi.gregset) != -1)
    {
      supply_gregset (&pi.gregset);
    }
#if defined (FP0_REGNUM)
  if (ioctl (pi.fd, PIOCGFPREG, &pi.fpregset) != -1)
    {
      supply_fpregset (&pi.fpregset);
    }
#endif
}

/*

GLOBAL FUNCTION

	fetch_core_registers -- fetch current registers from core file data

SYNOPSIS

	void fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
				   int which, unsigned in reg_addr)

DESCRIPTION

	Read the values of either the general register set (WHICH equals 0)
	or the floating point register set (WHICH equals 2) from the core
	file data (pointed to by CORE_REG_SECT), and update gdb's idea of
	their current values.  The CORE_REG_SIZE parameter is ignored.

NOTES

	Use the indicated sizes to validate the gregset and fpregset
	structures.
*/

void
fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
     char *core_reg_sect;
     unsigned core_reg_size;
     int which;
     unsigned int reg_addr;	/* Unused in this version */
{

  if (which == 0)
    {
      if (core_reg_size != sizeof (pi.gregset))
	{
	  warning ("wrong size gregset struct in core file");
	}
      else
	{
	  memcpy ((char *) &pi.gregset, core_reg_sect, sizeof (pi.gregset));
	  supply_gregset (&pi.gregset);
	}
    }
  else if (which == 2)
    {
      if (core_reg_size != sizeof (pi.fpregset))
	{
	  warning ("wrong size fpregset struct in core file");
	}
      else
	{
	  memcpy ((char *) &pi.fpregset, core_reg_sect, sizeof (pi.fpregset));
#if defined (FP0_REGNUM)
	  supply_fpregset (&pi.fpregset);
#endif
	}
    }
}

/*

LOCAL FUNCTION

	proc_init_failed - called whenever /proc access initialization fails

SYNOPSIS

	static void proc_init_failed (char *why)

DESCRIPTION

	This function is called whenever initialization of access to a /proc
	entry fails.  It prints a suitable error message, does some cleanup,
	and then invokes the standard error processing routine which dumps
	us back into the command loop.
 */

static void
proc_init_failed (why)
     char *why;
{
  print_sys_errmsg (pi.pathname, errno);
  kill (pi.pid, SIGKILL);
  close_proc_file (&pi);
  error (why);
  /* NOTREACHED */
}

/*

LOCAL FUNCTION

	close_proc_file - close any currently open /proc entry

SYNOPSIS

	static void close_proc_file (struct procinfo *pip)

DESCRIPTION

	Close any currently open /proc entry and mark the process information
	entry as invalid.  In order to ensure that we don't try to reuse any
	stale information, the pid, fd, and pathnames are explicitly
	invalidated, which may be overkill.

 */

static void
close_proc_file (pip)
     struct procinfo *pip;
{
  pip -> pid = 0;
  if (pip -> valid)
    {
      close (pip -> fd);
    }
  pip -> fd = -1;
  if (pip -> pathname)
    {
      free (pip -> pathname);
      pip -> pathname = NULL;
    }
  pip -> valid = 0;
}

/*

LOCAL FUNCTION

	open_proc_file - open a /proc entry for a given process id

SYNOPSIS

	static int open_proc_file (int pid, struct procinfo *pip, int mode)

DESCRIPTION

	Given a process id and a mode, close the existing open /proc
	entry (if any) and open one for the new process id, in the
	specified mode.  Once it is open, then mark the local process
	information structure as valid, which guarantees that the pid,
	fd, and pathname fields match an open /proc entry.  Returns
	zero if the open fails, nonzero otherwise.

	Note that the pathname is left intact, even when the open fails,
	so that callers can use it to construct meaningful error messages
	rather than just "file open failed".
 */

static int
open_proc_file (pid, pip, mode)
     int pid;
     struct procinfo *pip;
     int mode;
{
  pip -> valid = 0;		/* FIXME, what is this? ?!  */
  if (pip -> valid)
    {
      close (pip -> fd);
    }
  if (pip -> pathname == NULL)
    {
      pip -> pathname = xmalloc (32);
    }
  sprintf (pip -> pathname, PROC_NAME_FMT, pid);
  if ((pip -> fd = open (pip -> pathname, mode)) >= 0)
    {
      pip -> valid = 1;
      pip -> pid = pid;
    }
  return (pip -> valid);
}

static char *
mappingflags (flags)
     long flags;
{
  static char asciiflags[8];
  
  strcpy (asciiflags, "-------");
#if defined (MA_PHYS)
  if (flags & MA_PHYS)   asciiflags[0] = 'd';
#endif
  if (flags & MA_STACK)  asciiflags[1] = 's';
  if (flags & MA_BREAK)  asciiflags[2] = 'b';
  if (flags & MA_SHARED) asciiflags[3] = 's';
  if (flags & MA_READ)   asciiflags[4] = 'r';
  if (flags & MA_WRITE)  asciiflags[5] = 'w';
  if (flags & MA_EXEC)   asciiflags[6] = 'x';
  return (asciiflags);
}

static void
info_proc_flags (pip, summary)
     struct procinfo *pip;
     int summary;
{
  struct trans *transp;

  printf_filtered ("%-32s", "Process status flags:");
  if (!summary)
    {
      printf_filtered ("\n\n");
    }
  for (transp = pr_flag_table; transp -> name != NULL; transp++)
    {
      if (pip -> prstatus.pr_flags & transp -> value)
	{
	  if (summary)
	    {
	      printf_filtered ("%s ", transp -> name);
	    }
	  else
	    {
	      printf_filtered ("\t%-16s %s.\n", transp -> name, transp -> desc);
	    }
	}
    }
  printf_filtered ("\n");
}

static void
info_proc_stop (pip, summary)
     struct procinfo *pip;
     int summary;
{
  struct trans *transp;
  int why;
  int what;

  why = pip -> prstatus.pr_why;
  what = pip -> prstatus.pr_what;

  if (pip -> prstatus.pr_flags & PR_STOPPED)
    {
      printf_filtered ("%-32s", "Reason for stopping:");
      if (!summary)
	{
	  printf_filtered ("\n\n");
	}
      for (transp = pr_why_table; transp -> name != NULL; transp++)
	{
	  if (why == transp -> value)
	    {
	      if (summary)
		{
		  printf_filtered ("%s ", transp -> name);
		}
	      else
		{
		  printf_filtered ("\t%-16s %s.\n",
				   transp -> name, transp -> desc);
		}
	      break;
	    }
	}
      
      /* Use the pr_why field to determine what the pr_what field means, and
	 print more information. */
      
      switch (why)
	{
	  case PR_REQUESTED:
	    /* pr_what is unused for this case */
	    break;
	  case PR_JOBCONTROL:
	  case PR_SIGNALLED:
	    if (summary)
	      {
		printf_filtered ("%s ", signalname (what));
	      }
	    else
	      {
		printf_filtered ("\t%-16s %s.\n", signalname (what),
				 safe_strsignal (what));
	      }
	    break;
	  case PR_SYSENTRY:
	    if (summary)
	      {
		printf_filtered ("%s ", syscallname (what));
	      }
	    else
	      {
		printf_filtered ("\t%-16s %s.\n", syscallname (what),
				 "Entered this system call");
	      }
	    break;
	  case PR_SYSEXIT:
	    if (summary)
	      {
		printf_filtered ("%s ", syscallname (what));
	      }
	    else
	      {
		printf_filtered ("\t%-16s %s.\n", syscallname (what),
				 "Returned from this system call");
	      }
	    break;
	  case PR_FAULTED:
	    if (summary)
	      {
		printf_filtered ("%s ",
				 lookupname (faults_table, what, "fault"));
	      }
	    else
	      {
		printf_filtered ("\t%-16s %s.\n",
				 lookupname (faults_table, what, "fault"),
				 lookupdesc (faults_table, what));
	      }
	    break;
	  }
      printf_filtered ("\n");
    }
}

static void
info_proc_siginfo (pip, summary)
     struct procinfo *pip;
     int summary;
{
  struct siginfo *sip;

  if ((pip -> prstatus.pr_flags & PR_STOPPED) &&
      (pip -> prstatus.pr_why == PR_SIGNALLED ||
       pip -> prstatus.pr_why == PR_FAULTED))
    {
      printf_filtered ("%-32s", "Additional signal/fault info:");
      sip = &pip -> prstatus.pr_info;
      if (summary)
	{
	  printf_filtered ("%s ", signalname (sip -> si_signo));
	  if (sip -> si_errno > 0)
	    {
	      printf_filtered ("%s ", errnoname (sip -> si_errno));
	    }
	  if (sip -> si_code <= 0)
	    {
	      printf_filtered ("sent by pid %d, uid %d ", sip -> si_pid,
			       sip -> si_uid);
	    }
	  else
	    {
	      printf_filtered ("%s ", sigcodename (sip));
	      if ((sip -> si_signo == SIGILL) ||
		  (sip -> si_signo == SIGFPE) ||
		  (sip -> si_signo == SIGSEGV) ||
		  (sip -> si_signo == SIGBUS))
		{
		  printf_filtered ("addr=%#x ", sip -> si_addr);
		}
	      else if ((sip -> si_signo == SIGCHLD))
		{
		  printf_filtered ("child pid %u, status %u ",
				   sip -> si_pid,
				   sip -> si_status);
		}
	      else if ((sip -> si_signo == SIGPOLL))
		{
		  printf_filtered ("band %u ", sip -> si_band);
		}
	    }
	}
      else
	{
	  printf_filtered ("\n\n");
	  printf_filtered ("\t%-16s %s.\n", signalname (sip -> si_signo),
			   safe_strsignal (sip -> si_signo));
	  if (sip -> si_errno > 0)
	    {
	      printf_filtered ("\t%-16s %s.\n",
			       errnoname (sip -> si_errno),
			       safe_strerror (sip -> si_errno));
	    }
	  if (sip -> si_code <= 0)
	    {
	      printf_filtered ("\t%-16u %s\n", sip -> si_pid,
			       "PID of process sending signal");
	      printf_filtered ("\t%-16u %s\n", sip -> si_uid,
			       "UID of process sending signal");
	    }
	  else
	    {
	      printf_filtered ("\t%-16s %s.\n", sigcodename (sip),
			       sigcodedesc (sip));
	      if ((sip -> si_signo == SIGILL) ||
		  (sip -> si_signo == SIGFPE))
		{
		  printf_filtered ("\t%-16#x %s.\n", sip -> si_addr,
				   "Address of faulting instruction");
		}
	      else if ((sip -> si_signo == SIGSEGV) ||
		       (sip -> si_signo == SIGBUS))
		{
		  printf_filtered ("\t%-16#x %s.\n", sip -> si_addr,
				   "Address of faulting memory reference");
		}
	      else if ((sip -> si_signo == SIGCHLD))
		{
		  printf_filtered ("\t%-16u %s.\n", sip -> si_pid,
				   "Child process ID");
		  printf_filtered ("\t%-16u %s.\n", sip -> si_status,
				   "Child process exit value or signal");
		}
	      else if ((sip -> si_signo == SIGPOLL))
		{
		  printf_filtered ("\t%-16u %s.\n", sip -> si_band,
				   "Band event for POLL_{IN,OUT,MSG}");
		}
	    }
	}
      printf_filtered ("\n");
    }
}

static void
info_proc_syscalls (pip, summary)
     struct procinfo *pip;
     int summary;
{
  int syscallnum;

  if (!summary)
    {

#if 0	/* FIXME:  Needs to use gdb-wide configu