Public bug reported:
SRU Justification:
[Impact]
When the kernel configs CONFIG_IPMI_PANIC_EVENT or CONFIG_IPMI_PANIC_STRING
are enabled the ipmi_msghandler driver will attempt to send the kernel
panic event to the BMC to record in the SEL. It was found that this
causes a hang on BlueField which can block kdump from running and
rebooting the system after a kernel panic occurs.
[Fix]
The ipmi_msghandler driver requires the ipmi_smi_handlers "poll"
and "set_run_to_completion" callbacks to be implemented in order to
send the panic event. If those functions are not registered then panic
eventing will be skipped.
In the BlueField ipmb_host driver these callbacks are registered, but
are not implemented to do anything. When the IPMI panic handler runs it
attempts to send the panic request and waits for the operation to be
completed by polling. Because the poll handler is not fully
implemented, this causes an infinite loop.
The fix is to remove unimplemented ipmi_smi handlers because IPMI panic
eventing is not supported on BlueField.
[Test Case]
* Boot image on BF3 platform with updated ipmb_host driver
* Verify no error messages or failures when loading ipmb_host driver.
* Verify IPMI communication with BMC using "ipmitool mc info" and "ipmitool lan
print"
* Enable NMI watchdog, trigger CPU hard lockup, verify BF3 saves crash
information and reboots
automatically instead of hanging.
[Regression Potential]
Low potential for creating regression because the callback functions
that were removed were not implemented to do anything and the
ipmi_msghandler driver checks if the callbacks are NULL before calling
them.
** Affects: linux-bluefield (Ubuntu)
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux-bluefield in Ubuntu.
https://bugs.launchpad.net/bugs/2110498
Title:
ipmb_host: IPMI panic event causes hang
Status in linux-bluefield package in Ubuntu:
New
Bug description:
SRU Justification:
[Impact]
When the kernel configs CONFIG_IPMI_PANIC_EVENT or CONFIG_IPMI_PANIC_STRING
are enabled the ipmi_msghandler driver will attempt to send the kernel
panic event to the BMC to record in the SEL. It was found that this
causes a hang on BlueField which can block kdump from running and
rebooting the system after a kernel panic occurs.
[Fix]
The ipmi_msghandler driver requires the ipmi_smi_handlers "poll"
and "set_run_to_completion" callbacks to be implemented in order to
send the panic event. If those functions are not registered then panic
eventing will be skipped.
In the BlueField ipmb_host driver these callbacks are registered, but
are not implemented to do anything. When the IPMI panic handler runs it
attempts to send the panic request and waits for the operation to be
completed by polling. Because the poll handler is not fully
implemented, this causes an infinite loop.
The fix is to remove unimplemented ipmi_smi handlers because IPMI panic
eventing is not supported on BlueField.
[Test Case]
* Boot image on BF3 platform with updated ipmb_host driver
* Verify no error messages or failures when loading ipmb_host driver.
* Verify IPMI communication with BMC using "ipmitool mc info" and "ipmitool
lan print"
* Enable NMI watchdog, trigger CPU hard lockup, verify BF3 saves crash
information and reboots
automatically instead of hanging.
[Regression Potential]
Low potential for creating regression because the callback functions
that were removed were not implemented to do anything and the
ipmi_msghandler driver checks if the callbacks are NULL before calling
them.
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-bluefield/+bug/2110498/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : [email protected]
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
