With the introduction of kernel commit c6c5b14dac0d ("powerpc: make fadump
resilient with memory add/remove events") linux kernel now internally manages
the update of elfcorehdr during memory add/remove events. So no need to
re-register fadump if the /sys/kernel/fadump/hotplug_ready is set to 1.
No impact for kernels that do not have /sys/kernel/fadump/hotplug_ready
sysfs.
Relevant kernel commit links:
1. https://msgid.link/20240422195932.1583833-2-sourabhjain@linux.ibm.com
2. https://msgid.link/20240422195932.1583833-3-sourabhjain@linux.ibm.com
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
The fadump sysfs nodes /sys/kernel/fadump_[enabled|registered], have
been relocated to /sys/kernel/fadump/[enabled|registered] by kernel
commits d418b19f34ed ("powerpc/fadump: Reorganize /sys/kernel/fadump_*
sysfs files").
To ensure compatibility, symbolic links were added for each relocated
sysfs entry. Nonetheless, note that these symbolic links might be
removed later, as they have been deprecated by kernel commit
3f5f1f22ef10 ("Documentation/ABI: Mark /sys/kernel/fadump_* sysfs files
deprecated")
This patch updates the scripts to use the updated fadump sysfs files.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>
As FADump does not require an explicit elfcorehdr update whenever there is CPU
hotplug event so let's stop kdump service reload for FADump when CPU hotplug
event is triggered.
A new label is added to handle CPU and memory hotplug events separately. The
updated CPU hotplug event handler make sure that kdump service should not be
reloaded when FADump is configured.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
On powerpc, after hot add cpu and trigger crash on the hot-added cpu, the
kdump kernel hangs after "I'm in purgatory".
The current udev rules expects the dtb to be rebuit on cpu add/remove event.
But since powerpc does not follow the standard cpu hot add framework, it
only ejects online/offline event to user space when cpu is hot
added/removed, instead of add/remove event. Pingfan tried fixing that but
it didn't please the maintainer as it breaks some old userspace tools.
Due to the failure of dtb's rebuilding, KDump kernel fails to get the
'boot_cpuid' and eventually fails to boot [see early_init_dt_scan_cpus() in
arch/powerpc/kernel/prom.c file] if system crashes on hot-added CPU.
Work around it by changing udev rules on powerpc to onlne/offline.
As for offline message, it is even useless on powerpc, and can be dropped.
See the explain: On powerpc, /sys/devices/system/cpu/cpuX nodes are present
for all "possible", irrespective of whether a CPU is hot-added/removed.
crash_notes are already built for all /sys/devices/system/cpu/cpuX nodes and
these nodes are present for all "possible" CPUs
(online/offline/could-be-hot-removed/could-be-hot-added)
Signed-off-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Kairui Song <kasong@redhat.com>
