The patch titled Subject: panic: call panic handlers before panic_other_cpus_shutdown() has been added to the -mm mm-nonmm-unstable branch. Its filename is panic-call-panic-handlers-before-panic_other_cpus_shutdown.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Hamza Mahfooz hamzamahfooz@linux.microsoft.com Subject: panic: call panic handlers before panic_other_cpus_shutdown() Date: Fri, 21 Feb 2025 16:30:52 -0500

Since the panic handlers may require certain cpus to be online to panic gracefully, we should call them before turning off SMP. Without this re-ordering, on Hyper-V hv_panic_vmbus_unload() times out, because the vmbus channel is bound to VMBUS_CONNECT_CPU and unless the crashing cpu is the same as VMBUS_CONNECT_CPU, VMBUS_CONNECT_CPU will be offlined by crash_smp_send_stop() before the vmbus channel can be deconstructed.

Link: https://lkml.kernel.org/r/20250221213055.133849-1-hamzamahfooz@linux.microso... Signed-off-by: Hamza Mahfooz hamzamahfooz@linux.microsoft.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Baoquan he bhe@redhat.com Cc: Dexuan Cui decui@microsoft.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Haiyang Zhang haiyangz@microsoft.com Cc: Hamza Mahfooz hamzamahfooz@linux.microsoft.com Cc: Jani Nikula jani.nikula@intel.com Cc: John Ogness john.ogness@linutronix.de Cc: Petr Mladek pmladek@suse.com Cc: Ryo Takakura takakura@valinux.co.jp Cc: Wei Liu wei.liu@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

kernel/panic.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/kernel/panic.c~panic-call-panic-handlers-before-panic_other_cpus_shutdown +++ a/kernel/panic.c @@ -372,16 +372,16 @@ void panic(const char *fmt, ...) if (!_crash_kexec_post_notifiers) __crash_kexec(NULL);

- panic_other_cpus_shutdown(_crash_kexec_post_notifiers); - - printk_legacy_allow_panic_sync(); - /* * Run any panic handlers, including those that might need to * add information to the kmsg dump output. */ atomic_notifier_call_chain(&panic_notifier_list, 0, buf);

+ panic_other_cpus_shutdown(_crash_kexec_post_notifiers); + + printk_legacy_allow_panic_sync(); + panic_print_sys_info(false);

kmsg_dump_desc(KMSG_DUMP_PANIC, buf); _

Patches currently in -mm which might be from hamzamahfooz@linux.microsoft.com are

panic-call-panic-handlers-before-panic_other_cpus_shutdown.patch