|Summary:||kernel panic when removing active USB serial converter used as serial console|
|Product:||Red Hat Enterprise Linux 3||Reporter:||Richard Horwood <richard_horwood>|
|Component:||kernel||Assignee:||Pete Zaitcev <zaitcev>|
|Status:||CLOSED ERRATA||QA Contact:||Brian Brock <bbrock>|
|Version:||3.0||CC:||jbaron, petrides, riel|
|Fixed In Version:||RHSA-2006-0437||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2006-07-20 13:22:39 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
|Bug Depends On:|
Description Richard Horwood 2005-04-06 01:28:00 UTC
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.7.6) Gecko/20050322 Firefox/1.0.2 Description of problem: Installed a belkin USB to serial converter into system, and set up to work as a serial console for the system. Kernel recognises the adapter, and serial console works very well. /etc/inittab contains the line: cu:2345:respawn:/sbin/agetty -t60 -f /etc/issue.usb 19200 /dev/ttyUSB0 If the USB to serial converter is unplugged when an active agetty is running, the kernel panics. Version-Release number of selected component (if applicable): kernel-2.4.21-31.EL How reproducible: Always Steps to Reproduce: 1. Insert USB to serial adapter 2. If not already running, start agetty process on /dev/ttyUSB0 (or whatever tty) 3. unplug USB to serial adapter Actual Results: System fall down go boom. Kernel panic, system halted. Expected Results: The kernel should recognise the event and bypass any processess attached to that tty Additional info:
Comment 1 Richard Horwood 2005-04-06 06:31:29 UTC
*** Bug 153967 has been marked as a duplicate of this bug. ***
Comment 2 Richard Horwood 2005-04-07 01:51:19 UTC
FWIW, kernel trace as recorded (typed from notes, not exact grab): die [kernel] 0x1b0 ia64_do_page_fault [kernel] 0x350 ia64_leave_kernel [kernel] 0x0 serial_write [kernel] 0x100 opost_block [kernel] 0x300 write_chan [kernel] 0x280 tty_write [kernel] 0x680 sys_write [kernel] 0x1c0 ia64_ret_from_syscall [kernel] 0x0
Comment 3 Richard Horwood 2005-04-07 07:19:45 UTC
Note that problem cannot be reproduced with kernel 2.4.21-20-EL
Comment 4 Pete Zaitcev 2005-04-08 01:41:12 UTC
Ah-ha, finally, a traceback! This helps a lot, I can see now that this is likely to be the same problem as bug 132994. But please DO NOT DUP, for two reasons. 1) May be not the same, and it's much easier to dup than to divorce afterwards, 2) this bug crowns a chain of dups, which may have unrelated symptoms. Please download a test kernel 2.4.21-31.EL.usbserial.2 for a desirable architecture (ia64) and run tests. ftp://people.redhat.com/zaitcev/rhel3usb/ This test employs the small plug fix.
Comment 5 Richard Horwood 2005-04-11 00:25:51 UTC
With kernel 2.4.21-31.EL.usbserial.3 the problem does not exist. Disconnecting the USB converter simply kills the agetty process and the system seems to continue as normal. Messages follow, my notes in  [ USB Device inserted ] hub.c: new USB device 00:1d.1-2, assigned address 2 usb.c: USB device 2 (vend/prod 0x50d/0x109) is not claimed by any active driver. usb.c: registered new driver serial usbserial.c: USB Serial support registered for Generic usbserial.c: USB Serial Driver core v1.4 usbserial.c: USB Serial support registered for Magic Control Technology USB-RS232 usbserial.c: Magic Control Technology USB-RS232 converter detected usbserial.c: Magic Control Technology USB-RS232 converter now attached to ttyUSB0 (or usb/tts/0 for devfs) mct_u232.c: Magic Control Technology USB-RS232 converter driver v1.1 [ USB Device unplugged with agetty running on /dev/ttyUSB0 ] usb.c: USB disconnect on device 00:1d.1-2 address 2 usbserial.c: Magic Control Technology USB-RS232 converter now disconnected fromttyUSB0 Attached scsi generic sg2 at scsi0, channel 0, id 6, lun 0, type 3 [root@sandpit1 root]# uname -a Linux sandpit1 2.4.21-31.EL.usbserial.3 #1 SMP Tue Mar 22 19:56:52 EST 2005 ia64 ia64 ia64 GNU/Linux
Comment 9 Pete Zaitcev 2006-04-13 06:00:58 UTC
Created attachment 127694 [details] Candidate #2 - "Little Rework" This bug becomes the banner bug for the "Little Rework [of usbserial]".
Comment 10 Ernie Petrides 2006-04-21 04:07:13 UTC
A fix for this problem has just been committed to the RHEL3 U8 patch pool this evening (in kernel version 2.4.21-40.8.EL).
Comment 13 Joshua Giles 2006-05-30 16:23:28 UTC
A kernel has been released that contains a patch for this problem. Please verify if your problem is fixed with the latest available kernel from the RHEL3 public beta channel at rhn.redhat.com and post your results to this bugzilla.
Comment 14 Ernie Petrides 2006-05-30 20:22:24 UTC
Reverting to ON_QA.
Comment 16 Red Hat Bugzilla 2006-07-20 13:22:40 UTC
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 the 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-2006-0437.html