Description: Updates for powerpc crash kexec

Mamatha Inamdarrequested to merge
mainamdar/centos-stream-10:RHEL-76749 into main

JIRA: https://issues.redhat.com/browse/RHEL-76749

Build Info: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=66787277

Tested: Verified Brew build test kernel RPMs

Signed-off-by: Mamatha Inamdar minamdar@redhat.com

commit 6efbd5ddb6af0408301b4c15b413e6425c7650b2 Author: Sourabh Jain sourabhjain@linux.ibm.com Date: Sat Sep 21 16:07:45 2024 +0530

kexec/crash: no crash update when kexec in progress

The following errors are observed when kexec is done with SMT=off on
powerpc.

[  358.458385] Removing IBM Power 842 compression device
[  374.795734] kexec_core: Starting new kernel
[  374.795748] kexec: Waking offline cpu 1.
[  374.875695] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[  374.935833] kexec: Waking offline cpu 2.
[  375.015664] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
snip..
[  375.515823] kexec: Waking offline cpu 6.
[  375.635667] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[  375.695836] kexec: Waking offline cpu 7.

To avoid kexec kernel boot failure on PowerPC, all the present CPUs that
are offline are brought online during kexec.  For more information, refer
to commit e8e5c2155b00 ("powerpc/kexec: Fix orphaned offline CPUs across
kexec").  Bringing the CPUs online triggers the crash hotplug handler,
crash_handle_hotplug_event(), to update the kdump image.  Since the system
is on the kexec kernel boot path and the kexec lock is held, the
crash_handle_hotplug_event() function fails to acquire the same lock to
update the kdump image, resulting in the error messages mentioned above.

To fix this, return from crash_handle_hotplug_event() without printing the
error message if kexec is in progress.

The same applies to the crash_check_hotplug_support() function.  Return 0
if kexec is in progress because kernel is not in a position to update the
kdump image.

Link: https://lkml.kernel.org/r/20240921103745.560430-1-sourabhjain@linux.ibm.com
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan he <bhe@redhat.com>
Reported-by: Sachin P Bappalige <sachinpb@linux.vnet.ibm.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Mamatha Inamdar minamdar@redhat.com

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