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Date: Wed, 24 Jul 2013 06:33:31 GMT
From: Alexander Brovikov <alexander@brovikov.ru>
To: freebsd-gnats-submit@FreeBSD.org
Subject: [xen] [panic] XEN PV kernel 9.2-BETA1 panics on boot
X-Send-Pr-Version: www-3.1
X-GNATS-Notify:

>Number:         180788
>Category:       kern
>Synopsis:       [xen] [panic] XEN PV kernel 9.2-BETA1 panics on boot
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-xen
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Jul 24 06:40:00 UTC 2013
>Closed-Date:    
>Last-Modified:  Wed Aug  7 10:10:00 UTC 2013
>Originator:     Alexander Brovikov
>Release:        9.2-BETA1
>Organization:
>Environment:
FreeBSD 9.2-BETA1 #0: Wed Jul 24 06:06:39 YEKT 2013
    bas@freebsd92b1:/usr/obj/usr/src/sys/XEN i386
>Description:
XEN PV kernel (built from stock XEN conf file) 9.2-BETA1 panics on boot:

pid 25 (sh), uid 0: exited on signal 11
panic: removing pages from non-current pmap
cpuid = 0
KDB: enter: panic
[ thread pid 25 tid 100036 ]
Stopped at      kdb_enter+0x3a: movl    $0,kdb_why
db> 
db> bt
Tracing pid 25 tid 100036 td 0xc26f6bc0
kdb_enter(c04074b6,c04074b6,c044750f,ccb79944,0,...) at kdb_enter+0x3a/frame 0xccb7990c
panic(c044750f,0,c04465f7,e06,c01170c5,...) at panic+0x18c/frame 0xccb79938
pmap_remove_pages(c253e724,c04055fa,e8,0,c26f3000,...) at pmap_remove_pages+0x68c/frame 0xccb799b8
vmspace_exit(c26f6bc0,0,c04013a5,141,c0192e88,...) at vmspace_exit+0x90/frame 0xccb799d8
exit1(c26f6bc0,b,19,c26f320c,0,...) at exit1+0x62e/frame 0xccb79a28
sigexit(c26f6bc0,b,c0407561,b02,c05dd978,...) at sigexit+0xe43/frame 0xccb79c30
postsig(b,64,c040d916,fc,1,...) at postsig+0x20b/frame 0xccb79ce0
ast(ccb79d18) at ast+0x37f/frame 0xccb79d0c
vm86_biosret() at vm86_biosret+0x9c/frame 0xbf7fcc68
db> 
>How-To-Repeat:
Boot XEN PV kernel via pygrub on XenServer 6.2.
9.1-RELEASE in PV mode on same XS works well.
>Fix:


>Release-Note:
>Audit-Trail:
Responsible-Changed-From-To: freebsd-bugs->freebsd-xen 
Responsible-Changed-By: linimon 
Responsible-Changed-When: Wed Jul 24 14:15:37 UTC 2013 
Responsible-Changed-Why:  
Over to maintainer(s). 

http://www.freebsd.org/cgi/query-pr.cgi?pr=180788 

From: =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= <roger.pau@citrix.com>
To: <bug-followup@FreeBSD.org>, <alexander@brovikov.ru>
Cc:  
Subject: Re: kern/180788: [xen] [panic] XEN PV kernel 9.2-BETA1 panics on
 boot
Date: Fri, 26 Jul 2013 16:53:04 +0200

 This issue can be solved by reverting commit r244806. However this is
 not a long term option, r244806 just exposes a bug in Xen PV pmap code
 which should be fixed. It seems like Xen pmap is not able to cope with
 two processes sharing the same address space.

From: =?KOI8-R?B?4czFy9PBzsTSIOLSz9fJy8/X?= <alexander@brovikov.ru>
To: bug-followup@FreeBSD.org, alexander@brovikov.ru
Cc:  
Subject: Re: kern/180788: [xen] [panic] XEN PV kernel 9.2-BETA1 panics on boot
Date: Sat, 27 Jul 2013 13:24:38 +0600

 --047d7b2e4228ecaa4b04e2792619
 Content-Type: text/plain; charset=ISO-8859-1
 
 Confirm: workaround worked.
 
 --047d7b2e4228ecaa4b04e2792619
 Content-Type: text/html; charset=ISO-8859-1
 
 <div dir="ltr">Confirm: workaround worked.</div>
 
 --047d7b2e4228ecaa4b04e2792619--

From: dfilter@FreeBSD.ORG (dfilter service)
To: bug-followup@FreeBSD.org
Cc:  
Subject: Re: kern/180788: commit references a PR
Date: Wed,  7 Aug 2013 09:18:34 +0000 (UTC)

 Author: kib
 Date: Wed Aug  7 09:18:21 2013
 New Revision: 254053
 URL: http://svnweb.freebsd.org/changeset/base/254053
 
 Log:
   Revert the MFC of the r244237, done as r244806.  There are indeed bugs
   in XEN pmap.  The revert hides a panic with the cost of non-working
   vfork(2), which means more obscure misbehaviour in the usermode.
   Revert is only done on the stable branch to maintain the consistent
   erratic behaviour.
   
   PR:	kern/180788
 
 Modified:
   stable/9/sys/kern/kern_fork.c
 Directory Properties:
   stable/9/sys/   (props changed)
 
 Modified: stable/9/sys/kern/kern_fork.c
 ==============================================================================
 --- stable/9/sys/kern/kern_fork.c	Wed Aug  7 08:20:11 2013	(r254052)
 +++ stable/9/sys/kern/kern_fork.c	Wed Aug  7 09:18:21 2013	(r254053)
 @@ -150,7 +150,11 @@ sys_vfork(struct thread *td, struct vfor
  	int error, flags;
  	struct proc *p2;
  
 +#ifdef XEN
 +	flags = RFFDG | RFPROC; /* validate that this is still an issue */
 +#else
  	flags = RFFDG | RFPROC | RFPPWAIT | RFMEM;
 +#endif		
  	error = fork1(td, flags, 0, &p2, NULL, 0);
  	if (error == 0) {
  		td->td_retval[0] = p2->p_pid;
 _______________________________________________
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 http://lists.freebsd.org/mailman/listinfo/svn-src-all
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From: dfilter@FreeBSD.ORG (dfilter service)
To: bug-followup@FreeBSD.org
Cc:  
Subject: Re: kern/180788: commit references a PR
Date: Wed,  7 Aug 2013 10:08:02 +0000 (UTC)

 Author: kib
 Date: Wed Aug  7 10:07:55 2013
 New Revision: 254054
 URL: http://svnweb.freebsd.org/changeset/base/254054
 
 Log:
   Revert the MFC of the r244237, done as r244806.  There are indeed bugs
   in XEN pmap.  The revert hides a panic with the cost of non-working
   vfork(2), which means more obscure misbehaviour in the usermode.
   Revert is only done on the stable branch to maintain the consistent
   erratic behaviour.
   
   PR:	kern/180788
   Approved by:	re (marius)
 
 Modified:
   releng/9.2/sys/kern/kern_fork.c
 Directory Properties:
   releng/9.2/sys/   (props changed)
 
 Modified: releng/9.2/sys/kern/kern_fork.c
 ==============================================================================
 --- releng/9.2/sys/kern/kern_fork.c	Wed Aug  7 09:18:21 2013	(r254053)
 +++ releng/9.2/sys/kern/kern_fork.c	Wed Aug  7 10:07:55 2013	(r254054)
 @@ -150,7 +150,11 @@ sys_vfork(struct thread *td, struct vfor
  	int error, flags;
  	struct proc *p2;
  
 +#ifdef XEN
 +	flags = RFFDG | RFPROC; /* validate that this is still an issue */
 +#else
  	flags = RFFDG | RFPROC | RFPPWAIT | RFMEM;
 +#endif		
  	error = fork1(td, flags, 0, &p2, NULL, 0);
  	if (error == 0) {
  		td->td_retval[0] = p2->p_pid;
 _______________________________________________
 svn-src-all@freebsd.org mailing list
 http://lists.freebsd.org/mailman/listinfo/svn-src-all
 To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org"
 
>Unformatted:
