Description of problem: Customer is running EL4.5 as a HVM guest under Xen, using a terminal window and xm console to connect to the virtual serial console of the vm. When the user pastes a large amount of text (>512 bytes) into the console window, the guest kernel panics (UP) or deadlocks (SMP). The bug is due to a recursive lock request caused by not releasing the port lock in drivers/serial/8250.c:receive_chars() This is the same problem as reported upstream, with a fix posted here: http://lkml.org/lkml/2005/2/4/77 The second part of this fix was introduced in el4.5 but the first part was missed. However, the first part is needed as well. Version-Release number of selected component (if applicable): kernel-2.6.9-55 How reproducible: Every time. Steps to Reproduce: 1. start a xen hvm guest running the el 4.5 kernel 2. connect to the guest console with the command "xm console <domain>" 3. copy and paste more than 512 bytes into the console window Actual results: guest kernel panic or deadlock Expected results: no guest kernel panic or deadlock Additional info:
Created attachment 304435 [details] panic stack trace
Created attachment 304436 [details] fix for recursive lock request in 8250.c
Can't seem to get to the link above. http://marc.info/?l=linux-kernel&m=110780844815293&w=2 The second part of the patch was submitted by Aris .. cc'ing him on this BZ. The first part of the patch makes sense and IMO is stable enough to be included. I'll create a patch and test. P.
Sorry -- wrong link: http://marc.info/?l=linux-kernel&m=110751569018181&w=2 P.
Created attachment 304667 [details] RHEL4 fix for this issue
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
Updating PM score.
Committed in 78.9.EL . RPMS are available at http://people.redhat.com/vgoyal/rhel4/
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2009-1024.html