sh: revert addition of page fault notifiers

Just at the time you added them on sh we're removing them from other
architectures. As there's no user yet this patch just removes them
completely. Once you actually have a kprobes patch it should follow
the direct call to kprobes_fault_handler model that powerpc, s390 and
sparc64 employ in 2.6.22-rc1 and that I'm updating other architectures
to.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/mm/fault.c

@@ -15,43 +15,11 @@
 #include <linux/mm.h>
 #include <linux/hardirq.h>
 #include <linux/kprobes.h>
-#include <linux/kdebug.h>
 #include <asm/system.h>
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>
 #include <asm/kgdb.h>
 
-#ifdef CONFIG_KPROBES
-ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
-
-/* Hook to register for page fault notifications */
-int register_page_fault_notifier(struct notifier_block *nb)
-{
-	return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
-}
-
-int unregister_page_fault_notifier(struct notifier_block *nb)
-{
-	return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
-}
-
-static inline int notify_page_fault(enum die_val val, struct pt_regs *regs,
-				    int trap, int sig)
-{
-	struct die_args args = {
-		.regs = regs,
-		.trapnr = trap,
-	};
-	return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
-}
-#else
-static inline int notify_page_fault(enum die_val val, struct pt_regs *regs,
-				    int trap, int sig)
-{
-	return NOTIFY_DONE;
-}
-#endif
-
 /*
  * This routine handles page faults.  It determines the address,
  * and the problem, and then passes it off to one of the appropriate
@@ -69,11 +37,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
 	siginfo_t info;
 
 	trace_hardirqs_on();
-
-	if (notify_page_fault(DIE_PAGE_FAULT, regs,
-			      writeaccess, SIGSEGV) == NOTIFY_STOP)
-		return;
-
 	local_irq_enable();
 
 #ifdef CONFIG_SH_KGDB

include/asm-sh/kdebug.h

@@ -6,10 +6,6 @@
 /* Grossly misnamed. */
 enum die_val {
 	DIE_TRAP,
-	DIE_PAGE_FAULT,
 };
 
-int register_page_fault_notifier(struct notifier_block *nb);
-int unregister_page_fault_notifier(struct notifier_block *nb);
-
 #endif /* __ASM_SH_KDEBUG_H */