Subject: kern/30233: raidstrategy() isn't interrupt-safe
To: None <kern-bug-people@netbsd.org, gnats-admin@netbsd.org,>
From: Manuel Bouyer <bouyer@antioche.eu.org>
List: netbsd-bugs
Date: 05/14/2005 22:03:00
>Number: 30233
>Category: kern
>Synopsis: raidstrategy() isn't interrupt-safe
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: kern-bug-people
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Sat May 14 22:03:00 +0000 2005
>Originator: Manuel Bouyer
>Release: NetBSD 3.99.3
>Organization:
>Environment:
System: NetBSD rochebonne.antioche.eu.org 3.99.3 NetBSD 3.99.3 (ROCHEBONNE) #0: Sat May 14 15:33:21 CEST 2005 bouyer@pop.lip6.fr:/local/pop1/bouyer/tmp/i386/obj/local/pop1/bouyer/current/src/sys/arch/i386/compile/ROCHEBONNE i386
Architecture: i386
Machine: i386
>Description:
Quoting a post from Jason Thorpe on tech-kern:
> There are lots of other things that might cause a disk's strategy
> routine to be called from interrupt context (ccd / raidframe are good
> examples). Really, we need to audit ALL of the disk strategy
> routines and ensure that they are IPL_BIO interrupt-context safe.
raidstrategy() isn't safe to call from interrupt context: it ends up
calling pool_get(PR_WAITOK):
raidstrategy()
raidstart()
rf_DoAccess()
rf_AllocRaidAccDesc()
pool_get()
There may be other problems too other problems when called from
interrupt context too (are the locks interrupt-safe ?).
>How-To-Repeat:
An easy way to trigger a pool_get() panic is to export a partition
from a raidframe device to a guest Xen domain, as reported by
Yoshito Komatsu on port-xen.
>Fix:
None provided.