Revert "powerpc: Do not call ppc_md.panic in fadump panic notifier"

This reverts commit a3b2cb30f252b21a6f962e0dd107c8b897ca65e4.

That commit tried to fix problems with panic on powerpc in certain
circumstances, where some output from the generic panic code was being
dropped.

Unfortunately, it breaks things worse in other circumstances. In
particular when running a PAPR guest, it will now attempt to reboot
instead of informing the hypervisor (KVM or PowerVM) that the guest
has crashed. The crash notification is important to some
virtualization management layers.

Revert it for now until we can come up with a better solution.

Fixes: a3b2cb30f252 ("powerpc: Do not call ppc_md.panic in fadump panic notifier")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[mpe: Tweak change log a bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 0 insertions, 22 deletions

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 04ea5c04fd24..3c2c2688918f 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -1462,25 +1462,6 @@ static void fadump_init_files(void)
 	return;
 }
 
-static int fadump_panic_event(struct notifier_block *this,
-			      unsigned long event, void *ptr)
-{
-	/*
-	 * If firmware-assisted dump has been registered then trigger
-	 * firmware-assisted dump and let firmware handle everything
-	 * else. If this returns, then fadump was not registered, so
-	 * go through the rest of the panic path.
-	 */
-	crash_fadump(NULL, ptr);
-
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block fadump_panic_block = {
-	.notifier_call = fadump_panic_event,
-	.priority = INT_MIN /* may not return; must be done last */
-};
-
 /*
  * Prepare for firmware-assisted dump.
  */
@@ -1513,9 +1494,6 @@ int __init setup_fadump(void)
 		init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
 	fadump_init_files();
 
-	atomic_notifier_chain_register(&panic_notifier_list,
-					&fadump_panic_block);
-
 	return 1;
 }
 subsys_initcall(setup_fadump);