servtgt.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 **************************************************************************
 *
 *  Component:	RDB servers
 *  Module:	servtgt.c
 *
 * $Id: servtgt.c,v 1.3 2002/02/01 17:00:01 joel Exp $
 *
 **************************************************************************
 */

#include <string.h>
#include <sys/errno.h>
#include <rdbg/rdbg.h>
#include <rdbg/servrpc.h>
#include <sys/socket.h>
#include <assert.h>

#ifdef DDEBUG
#define	Ptrace	TgtDbgPtrace
#else
#define Ptrace	TgtRealPtrace
#endif

/*
 * TgtBreakRestoreOrig - Restore original instruction at "addr"
 * just before single-stepping it.
 */

  int
TgtBreakRestoreOrig (int pid, void *addr, void *addr2)
            /*
             * Process identifier 
             */
            /*
             * Breakpoint address 
             */
            /*
             * Original instruction or bkpt number 
             */
{
  int ret;
  int l;

  l = (long) Ptrace (RPT_PEEKTEXT, pid, addr, 0, NULL); /* assume ok */
  ret = ORG_BREAK (l, (UINT32) addr2);  /* reconstruct old instr */
  ret = Ptrace (RPT_POKETEXT, pid, addr, ret, NULL);    /* poke back old */
  return ret;
}

/*
 *
 *  TgtBreakCancelStep - Restore the breakpoint at "addr" if the single-step
 *  has failed at the ptrace level.
 */

#define BKPT0(plst)     ((BASE_BREAK*)(plst)->break_list)

  void
TgtBreakCancelStep (PID_LIST * plst)
{
  assert (plst->break_list);
  assert (BKPT0 (plst)->clr_step);

  if (plst->break_list && BKPT0 (plst)->clr_step) {
    int idx = BKPT0 (plst)->last_break;
    int data;

    data = Ptrace (RPT_PEEKTEXT, plst->pid,
                   (char *) plst->break_list[idx].ee_loc, 0, NULL);
    assert (!IS_BREAK (data));
    Ptrace (RPT_POKETEXT, plst->pid,
            (char *) plst->break_list[idx].ee_loc,
            (int) SET_BREAK (data), NULL);
  }
}

/*
 * TgtCreateNew - add a new process into the process management lists.
 */

  void
TgtCreateNew (PID pid, int conn, INT32 child, char *name, Boolean spawn)
{
  int idx;

  for (idx = 0; idx < pid_list_cnt; idx++)
    if (!pid_list[idx].pid)
      break;                    /* find empty */

  if (idx >= pid_list_cnt) {    /* no empties, add more */
    PID_LIST *tmp_pid_list = pid_list;

    pid_list_cnt += PID_LIST_INC;
    pid_list = (PID_LIST *) Realloc (pid_list,  /* get new or extend */
                                     pid_list_cnt * sizeof (PID_LIST));
    if (!pid_list) {            /* out of memory */
      pid_list_cnt -= PID_LIST_INC;
      if (pid_list_cnt) {       /* realloc failed - malloc again */
        pid_list = tmp_pid_list;
        /*
         * above relies on old pointer being valid after failed realloc 
         */
      }
      return;                   /* failed */
    }
    /*
     * now clear newly added space 
     */
    memset (pid_list + pid_list_cnt - PID_LIST_INC, 0,
            PID_LIST_INC * sizeof (PID_LIST));
    idx = pid_list_cnt - PID_LIST_INC;
  } else                        /* clear entry we found */
    memset (&pid_list[idx], 0, sizeof (PID_LIST));

  /*
   * now fill in empty entry 
   */
  pid_list[idx].pid = pid;
  pid_list[idx].running = 1;    /* we have not called wait yet */
  pid_list[idx].primary_conn = (UCHAR) conn;    /* primary owner */
  if (conn != -1) {             /* found caller */
    pid_list[idx].owners = 1;
    PIDMAP_SET (conn, idx);     /* mask in */
  }
  pid_list[idx].thread = (UINT32) - 1;  /* no thread for now */
  pid_list[idx].last_start = LAST_START;    /* handle MiX bug */

  pid_list[idx].name = name ? (char *) StrDup (name) : (char *) NULL;

}

/*
 * TgtNotifyWaitChange - send event to clients indicating child changed state.
 */

  void
TgtNotifyWaitChange (PID pid, int status, Boolean exclude)
{
  int conn, idx;

  idx = FindPidEntry (pid);     /* locate the pid that changed */
  if (idx < 0) {
    DPRINTF (("TgtNotifyWaitChange: pid %d not in our list\n", (int) pid));
    return;                     /* not in our list */
  }
  pid_list[idx].running = 0;    /* not running */
  pid_list[idx].state = status; /* save status of stop/term */
  if (!pid_list[idx].owners && !STS_SIGNALLED (status))
    TgtDelete (&pid_list[idx], -1, 0);  /* terminated and no owners */
  else {                        /* normal cases */
    for (conn = 0; conn < conn_list_cnt; conn++) {  /* now find all interested clients */
      if (!conn_list[conn].in_use   /* free entry */
          || !PIDMAP_TEST (conn, idx))
        continue;               /* not using this pid */
      if (conn == exclude)
        continue;               /* do not do this one */
      TspSendWaitChange (conn, BMSG_WAIT, 1, pid, 0, False);    /* notify of change */
    }
  }
}

/*
 *  TgtNotifyAll - send a message to all clients interested in process.
 */

  void
TgtNotifyAll (int pid_idx, BACK_MSG msg, UINT16 spec,
              UINT32 context, int exclude, Boolean force)
{
  int conn;

  DPRINTF (("TgtNotifyAll: msg %d (%s) for pid_idx=%d (%d,%d)\n",
            msg, BmsgNames[msg], pid_idx, exclude, force));
  for (conn = 0; conn < conn_list_cnt; conn++)
    if (conn_list[conn].in_use  /* not free */
        && PIDMAP_TEST (conn, pid_idx)) {
      if (conn != exclude)
        TspSendWaitChange (conn, msg, spec, pid_list[pid_idx].pid, context,
                           force);
    }
}

/*
 * TgtDelete - mark process as now uncontrolled.
 *
 *  Notes:
 *     - this function removes a process from the process list.
 *     - the notify argument indicates a message to send if needed.
 */

  void
TgtDelete (PID_LIST * plst, int conn_idx, BACK_MSG notify)
{
  int idx = plst - pid_list, cnt, conn;

  /*
   * found 
   */
  cnt = pid_list[idx].owners;
  if (cnt) {                    /* some connections to break */
    for (conn = 0; cnt && conn < conn_list_cnt; conn++)
      if (conn_list[conn].in_use    /* not free */
          && PIDMAP_TEST (conn, idx)) { /* found one that uses it */
        PIDMAP_CLEAR (conn, idx);
        if (notify && conn != conn_idx)
          TspSendWaitChange (conn, notify, 0, plst->pid, 0, True);
        if (!--cnt)
          break;
      }
  }
  if (pid_list[idx].name)
    Free (pid_list[idx].name);  /* free string name back */
  /*
   * Free breakpoint list 
   */
  if (pid_list[idx].break_list != NULL) {
    Free (pid_list[idx].break_list);
  }
  pid_list[idx].pid = 0;        /* gone */
}

/*
 * TgtKillAndDelete - kill or detach process and remove entry.
 */

  int
TgtKillAndDelete (PID_LIST * plst, struct svc_req *rqstp, Boolean term)
{
  ptrace_in pin;                /* used for ptrace call */
  ptrace_out *pout;

  /*
   * Remove breakpoints 
   */
  if (plst->break_alloc > 0) {
    pin.pid = plst->pid;
    pin.addr.req = RPT_CLRBREAK;
    pin.data = 0;               /* clear all */
    pin.flags = PTRFLG_NON_OWNER;
    pout = RPCGENSRVNAME (ptrace_2_svc) (&pin, rqstp);
    if (pout->result < 0) {
      DPRINTF (("TgtKillAndDelete: RPT_CLRBREAK failed %d\n", getErrno ()));
      return -1;
    }
  }

  if (term) {                   /* kill */
    pin.addr.ptrace_addr_data_in_u.address = 0;
    pin.data = -1;              /* Don't want notification from slave */
    pin.addr.req = RPT_KILL;
  } else {                      /* detach */
    pin.addr.ptrace_addr_data_in_u.address = 1;
    pin.data = 0;
    pin.addr.req = RPT_DETACH;
  }
  pin.pid = plst->pid;
  pin.flags = PTRFLG_FREE | PTRFLG_NON_OWNER;

  DPRINTF (("TgtKillAndDelete: ptrace_2_svc (%s (%d), %d)\n",
            PtraceName (pin.addr.req), pin.addr.req, pin.pid));

  pout = RPCGENSRVNAME (ptrace_2_svc) (&pin, rqstp);    /* start it */
  if (pout->errNo == ESRCH && plst->pid)
    TgtDelete (plst, -1, BMSG_KILLED);  /* only entry remains */
  return 0;
}

/*
 * TgtDetachCon - detach a connection's ownership of a process.
 */

  void
TgtDetachCon (int conn_idx, int pid_idx, Boolean delete)
{
  if ((unsigned) pid_idx >= pid_list_cnt || !pid_list[pid_idx].pid)
    return;                     /* not valid */
  if (PIDMAP_TEST (conn_idx, pid_idx)) {    /* if an owner, release control */
    PIDMAP_CLEAR (conn_idx, pid_idx);

    if (pid_list[pid_idx].owners)
      pid_list[pid_idx].owners--;
    if (pid_list[pid_idx].primary_conn == conn_idx)
      pid_list[pid_idx].primary_conn = NO_PRIMARY;
    if (delete
        && !pid_list[pid_idx].owners && PROC_TERMINATED (pid_list + pid_idx))
      TgtDelete (&pid_list[pid_idx], -1, 0);    /* remove entry */
  }
}