more checking of process group consistency; enterpgrp returns a value

SCCS-vsn: sys/kern/kern_proc.c 7.21

diff --git a/usr/src/sys/kern/kern_proc.c b/usr/src/sys/kern/kern_proc.c
index 64b28d8..6b72fcb 100644 (file)
--- a/usr/src/sys/kern/kern_proc.c
+++ b/usr/src/sys/kern/kern_proc.c
@@ -4,7 +4,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)kern_proc.c 7.20 (Berkeley) %G%
+ *     @(#)kern_proc.c 7.21 (Berkeley) %G%

  */
 
 #include <sys/param.h>
  */
 
 #include <sys/param.h>


@@ -150,6 +150,8 @@ enterpgrp(p, pgid, mksess)
                panic("enterpgrp: session leader attempted setpgrp");
 #endif
        if (pgrp == NULL) {
                panic("enterpgrp: session leader attempted setpgrp");
 #endif
        if (pgrp == NULL) {

+               pid_t savepid = p->p_pid;
+               struct proc *np;

                /*
                 * new process group
                 */
                /*
                 * new process group
                 */


@@ -159,6 +161,8 @@ enterpgrp(p, pgid, mksess)
 #endif
                MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
                       M_WAITOK);
 #endif
                MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
                       M_WAITOK);

+               if ((np = pfind(savepid)) == NULL || np != p)
+                       return (ESRCH);

                if (mksess) {
                        register struct session *sess;
 
                if (mksess) {
                        register struct session *sess;
 


@@ -189,7 +193,7 @@ enterpgrp(p, pgid, mksess)
                pgrp->pg_jobc = 0;
                pgrp->pg_mem = NULL;
        } else if (pgrp == p->p_pgrp)
                pgrp->pg_jobc = 0;
                pgrp->pg_mem = NULL;
        } else if (pgrp == p->p_pgrp)

-               return;
+               return (0);

 
        /*
         * Adjust eligibility of affected pgrps to participate in job control.
 
        /*
         * Adjust eligibility of affected pgrps to participate in job control.


@@ -202,13 +206,16 @@ enterpgrp(p, pgid, mksess)
        /*
         * unlink p from old process group
         */
        /*
         * unlink p from old process group
         */

-       for (pp = &p->p_pgrp->pg_mem; *pp; pp = &(*pp)->p_pgrpnxt)
+       for (pp = &p->p_pgrp->pg_mem; *pp; pp = &(*pp)->p_pgrpnxt) {

                if (*pp == p) {
                        *pp = p->p_pgrpnxt;
                if (*pp == p) {
                        *pp = p->p_pgrpnxt;

-                       goto done;
+                       break;

                }
                }

-       panic("enterpgrp: can't find p on old pgrp");
-done:
+       }
+#ifdef DIAGNOSTIC
+       if (pp == NULL)
+               panic("enterpgrp: can't find p on old pgrp");
+#endif

        /*
         * delete old if empty
         */
        /*
         * delete old if empty
         */


@@ -220,6 +227,7 @@ done:
        p->p_pgrp = pgrp;
        p->p_pgrpnxt = pgrp->pg_mem;
        pgrp->pg_mem = p;
        p->p_pgrp = pgrp;
        p->p_pgrpnxt = pgrp->pg_mem;
        pgrp->pg_mem = p;

+       return (0);

 }
 
 /*
 }
 
 /*


@@ -230,16 +238,20 @@ leavepgrp(p)
 {
        register struct proc **pp = &p->p_pgrp->pg_mem;
 
 {
        register struct proc **pp = &p->p_pgrp->pg_mem;
 

-       for (; *pp; pp = &(*pp)->p_pgrpnxt)
+       for (; *pp; pp = &(*pp)->p_pgrpnxt) {

                if (*pp == p) {
                        *pp = p->p_pgrpnxt;
                if (*pp == p) {
                        *pp = p->p_pgrpnxt;

-                       goto done;
+                       break;

                }
                }

-       panic("leavepgrp: can't find p in pgrp");
-done:
+       }
+#ifdef DIAGNOSTIC
+       if (pp == NULL)
+               panic("leavepgrp: can't find p in pgrp");
+#endif

        if (!p->p_pgrp->pg_mem)
                pgdelete(p->p_pgrp);
        p->p_pgrp = 0;
        if (!p->p_pgrp->pg_mem)
                pgdelete(p->p_pgrp);
        p->p_pgrp = 0;

+       return (0);

 }
 
 /*
 }
 
 /*


@@ -253,13 +265,16 @@ pgdelete(pgrp)
        if (pgrp->pg_session->s_ttyp != NULL && 
            pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
                pgrp->pg_session->s_ttyp->t_pgrp = NULL;
        if (pgrp->pg_session->s_ttyp != NULL && 
            pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
                pgrp->pg_session->s_ttyp->t_pgrp = NULL;

-       for (; *pgp; pgp = &(*pgp)->pg_hforw)
+       for (; *pgp; pgp = &(*pgp)->pg_hforw) {

                if (*pgp == pgrp) {
                        *pgp = pgrp->pg_hforw;
                if (*pgp == pgrp) {
                        *pgp = pgrp->pg_hforw;

-                       goto done;
+                       break;

                }
                }

-       panic("pgdelete: can't find pgrp on hash chain");
-done:
+       }
+#ifdef DIAGNOSTIC
+       if (pgp == NULL)
+               panic("pgdelete: can't find pgrp on hash chain");
+#endif

        if (--pgrp->pg_session->s_count == 0)
                FREE(pgrp->pg_session, M_SESSION);
        FREE(pgrp, M_PGRP);
        if (--pgrp->pg_session->s_count == 0)
                FREE(pgrp->pg_session, M_SESSION);
        FREE(pgrp, M_PGRP);