CVS commit: src/sys/net

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Sun Mar 13 21:32:27 UTC 2022

Modified Files:
        src/sys/net: if_tun.c

Log Message:
tun(4): Reduce lock from IPL_NET to IPL_SOFTNET.

This is never taken from hardware interrupt handlers any more, as far
as I can tell -- only SOFTINT_NET soft interrupt handlers.

This avoids trying to take an adaptive lock, proc_lock, in fownsignal
while holding a spin lock.  Unfortunately, it doesn't entirely fix the
problem -- proc_lock is at IPL_NONE, and is held across some not
entirely trivial computations like allocating a new pid table.  So it
would really be better if we had some way to deliver SIGIO without
taking proc_lock.

Reported-by: syzbot+3dd54993d3e92e697e72%syzkaller.appspotmail.com@localhost
Reported-by: syzbot+aca29415f2f0bf23f082%syzkaller.appspotmail.com@localhost


To generate a diff of this commit:
cvs rdiff -u -r1.167 -r1.168 src/sys/net/if_tun.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.