[POWERPC] Minor fault path optimization

Call the kprobes pagefault handler directly instead of going through
the complex notifier chain.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 15 insertions, 3 deletions

diff --git a/include/asm-powerpc/kdebug.h b/include/asm-powerpc/kdebug.h
index 532bfee934f4..df996b933def 100644
--- a/include/asm-powerpc/kdebug.h
+++ b/include/asm-powerpc/kdebug.h
@@ -18,8 +18,20 @@ struct die_args {
 
 extern int register_die_notifier(struct notifier_block *);
 extern int unregister_die_notifier(struct notifier_block *);
-extern int register_page_fault_notifier(struct notifier_block *);
-extern int unregister_page_fault_notifier(struct notifier_block *);
+
+/*
+ * These are only here because kprobes.c wants them to implement a
+ * blatant layering violation.  Will hopefully go away soon once all
+ * architectures are updated.
+ */
+static inline int register_page_fault_notifier(struct notifier_block *nb)
+{
+        return 0;
+}
+static inline int unregister_page_fault_notifier(struct notifier_block *nb)
+{
+        return 0;
+}
 extern struct atomic_notifier_head powerpc_die_chain;
 
 /* Grossly misnamed. */
@@ -29,7 +41,6 @@ enum die_val {
         DIE_DABR_MATCH,
         DIE_BPT,
         DIE_SSTEP,
-        DIE_PAGE_FAULT,
 };
 
 static inline int notify_die(enum die_val val,char *str,struct pt_regs *regs,long err,int trap, int sig)
diff --git a/include/asm-powerpc/kprobes.h b/include/asm-powerpc/kprobes.h
index fc713e595982..b0e40ff32ee0 100644
--- a/include/asm-powerpc/kprobes.h
+++ b/include/asm-powerpc/kprobes.h
@@ -116,5 +116,6 @@ struct kprobe_ctlblk {
 
 extern int kprobe_exceptions_notify(struct notifier_block *self,
                                         unsigned long val, void *data);
+extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
 #endif /* __KERNEL__ */
 #endif  /* _ASM_POWERPC_KPROBES_H */