ready to use "safepri" from machdep

SCCS-vsn: sys/kern/kern_synch.c 7.12

diff --git a/usr/src/sys/kern/kern_synch.c b/usr/src/sys/kern/kern_synch.c
index 61b3f79..659b766 100644 (file)
--- a/usr/src/sys/kern/kern_synch.c
+++ b/usr/src/sys/kern/kern_synch.c
@@ -3,7 +3,7 @@
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *

- *     @(#)kern_synch.c        7.11 (Berkeley) %G%
+ *     @(#)kern_synch.c        7.12 (Berkeley) %G%

  */
 
 #include "machine/pte.h"
  */
 
 #include "machine/pte.h"


@@ -210,6 +210,17 @@ struct slpque {
        struct proc **sq_tailp;
 } slpque[SQSIZE];
 
        struct proc **sq_tailp;
 } slpque[SQSIZE];
 

+/*
+ * During autoconfiguration or after a panic, a sleep will simply
+ * lower the priority briefly to allow interrupts, then return.
+ * The priority to be used (safepri) is machine-dependent, thus this
+ * value is initialized and maintained in the machine-dependent layers.
+ * This priority will typically be 0, or the lowest priority
+ * that is safe for use on the interrupt stack; it can be made
+ * higher to block network software interrupts after panics.
+ */
+int safepri;
+

 /*
  * General sleep call.
  * Suspends current process until a wakeup is made on chan.
 /*
  * General sleep call.
  * Suspends current process until a wakeup is made on chan.


@@ -245,7 +256,7 @@ tsleep(chan, pri, wmesg, timo)
                 * don't run any other procs or panic below,
                 * in case this is the idle process and already asleep.
                 */
                 * don't run any other procs or panic below,
                 * in case this is the idle process and already asleep.
                 */

-               (void) spl0();
+               splx(safepri);

                splx(s);
                return (0);
        }
                splx(s);
                return (0);
        }


@@ -263,43 +274,44 @@ tsleep(chan, pri, wmesg, timo)
        else
                *qp->sq_tailp = rp;
        *(qp->sq_tailp = &rp->p_link) = 0;
        else
                *qp->sq_tailp = rp;
        *(qp->sq_tailp = &rp->p_link) = 0;

+       if (timo)
+               timeout(endtsleep, (caddr_t)rp, timo);

        /*
        /*

-        * If we stop in CURSIG/issig(), wakeup may already
-        * have happened when we return.
-        * rp->p_wchan will then be 0.
+        * If we stop in CURSIG/issig(), a wakeup or a SIGCONT
+        * (or both) could occur while we were stopped.
+        * A SIGCONT would cause us to be marked as SSLEEP
+        * without resuming us, thus we must be ready for sleep
+        * when CURSIG is called.  If the wakeup happens while we're
+        * stopped, rp->p_wchan will be 0 upon return from CURSIG.

         */
        if (catch) {
         */
        if (catch) {

+               rp->p_flag |= SSINTR;

                if (sig = CURSIG(rp)) {
                        if (rp->p_wchan)
                                unsleep(rp);
                        rp->p_stat = SRUN;
                if (sig = CURSIG(rp)) {
                        if (rp->p_wchan)
                                unsleep(rp);
                        rp->p_stat = SRUN;

-                       splx(s);
-                       if (u.u_sigintr & sigmask(sig))
-                               return (EINTR);
-                       return (ERESTART);
+                       goto resume;

                }
                if (rp->p_wchan == 0) {
                }
                if (rp->p_wchan == 0) {

-                       splx(s);
-                       return (0);
+                       catch = 0;
+                       goto resume;

                }
                }

-               rp->p_flag |= SSINTR;

        }
        rp->p_stat = SSLEEP;
        }
        rp->p_stat = SSLEEP;

-       if (timo)
-               timeout(endtsleep, (caddr_t)rp, timo);

        (void) spl0();
        u.u_ru.ru_nvcsw++;
        swtch();
        (void) spl0();
        u.u_ru.ru_nvcsw++;
        swtch();

+resume:

        curpri = rp->p_usrpri;
        splx(s);
        rp->p_flag &= ~SSINTR;
        if (rp->p_flag & STIMO) {
                rp->p_flag &= ~STIMO;
        curpri = rp->p_usrpri;
        splx(s);
        rp->p_flag &= ~SSINTR;
        if (rp->p_flag & STIMO) {
                rp->p_flag &= ~STIMO;

-               return (EWOULDBLOCK);
-       }
-       if (timo)
+               if (catch == 0 || sig == 0)
+                       return (EWOULDBLOCK);
+       } else if (timo)

                untimeout(endtsleep, (caddr_t)rp);
                untimeout(endtsleep, (caddr_t)rp);

-       if (catch && (sig = CURSIG(rp))) {
+       if (catch && (sig != 0 || (sig = CURSIG(rp)))) {

                if (u.u_sigintr & sigmask(sig))
                        return (EINTR);
                return (ERESTART);
                if (u.u_sigintr & sigmask(sig))
                        return (EINTR);
                return (ERESTART);


@@ -356,7 +368,7 @@ sleep(chan, pri)
                 * don't run any other procs or panic below,
                 * in case this is the idle process and already asleep.
                 */
                 * don't run any other procs or panic below,
                 * in case this is the idle process and already asleep.
                 */

-               (void) spl0();
+               splx(safepri);

                splx(s);
                return;
        }
                splx(s);
                return;
        }