x86/mce: Correct the detection of invalid notifier priorities

Commit

  c9c6d216 ("x86/mce: Rename "first" function as "early"")

changed the enumeration of MCE notifier priorities. Correct the check
for notifier priorities to cover the new range.

 [ bp: Rewrite commit message, remove superfluous brackets in
   conditional. ]

Fixes: c9c6d216 ("x86/mce: Rename "first" function as "early"")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201106141216.2062-2-thunder.leizhen@huawei.com

arch/x86/include/asm/mce.h

@@ -177,7 +177,8 @@ enum mce_notifier_prios {
 	MCE_PRIO_EXTLOG,
 	MCE_PRIO_UC,
 	MCE_PRIO_EARLY,
-	MCE_PRIO_CEC
+	MCE_PRIO_CEC,
+	MCE_PRIO_HIGHEST = MCE_PRIO_CEC
 };
 
 struct notifier_block;

arch/x86/kernel/cpu/mce/core.c

@@ -162,7 +162,8 @@ EXPORT_SYMBOL_GPL(mce_log);
 
 void mce_register_decode_chain(struct notifier_block *nb)
 {
-	if (WARN_ON(nb->priority > MCE_PRIO_MCELOG && nb->priority < MCE_PRIO_EDAC))
+	if (WARN_ON(nb->priority < MCE_PRIO_LOWEST ||
+		    nb->priority > MCE_PRIO_HIGHEST))
 		return;
 
 	blocking_notifier_chain_register(&x86_mce_decoder_chain, nb);