Re: rwsleep and stopped process

[Alexander Bluhm]

On Sun, Mar 01, 2020 at 02:16:20PM +0100, Mark Kettenis wrote:
> This probably means that msleep(4) has a similar issue.

Here is the diff for msleep() and rwsleep().

bluhm

Index: kern/kern_synch.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/kern/kern_synch.c,v
retrieving revision 1.162
diff -u -p -r1.162 kern_synch.c
--- kern/kern_synch.c   30 Jan 2020 08:51:27 -0000      1.162
+++ kern/kern_synch.c   1 Mar 2020 13:50:29 -0000
@@ -259,7 +259,6 @@ msleep(const volatile void *ident, struc

        sleep_setup(&sls, ident, priority, wmesg);
        sleep_setup_timeout(&sls, timo);
-       sleep_setup_signal(&sls);

        /* XXX - We need to make sure that the mutex doesn't
         * unblock splsched. This can be made a bit more
@@ -268,6 +267,8 @@ msleep(const volatile void *ident, struc
        spl = MUTEX_OLDIPL(mtx);
        MUTEX_OLDIPL(mtx) = splsched();
        mtx_leave(mtx);
+       /* signal may stop the process, release mutex before that */
+       sleep_setup_signal(&sls);

        error = sleep_finish_all(&sls, 1);

@@ -320,9 +321,10 @@ rwsleep(const volatile void *ident, stru

        sleep_setup(&sls, ident, priority, wmesg);
        sleep_setup_timeout(&sls, timo);
-       sleep_setup_signal(&sls);

        rw_exit(rwl);
+       /* signal may stop the process, release rwlock before that */
+       sleep_setup_signal(&sls);

        error = sleep_finish_all(&sls, 1);