[SPARC64]: Optimize fault kprobe handling just like powerpc.

And eliminate DIE_GPF while we're at it.

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 29 insertions, 44 deletions

diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c
index a44fe47a3c2b..c93a15b785fa 100644
--- a/arch/sparc64/kernel/kprobes.c
+++ b/arch/sparc64/kernel/kprobes.c
@@ -313,7 +313,7 @@ out:
         return 1;
 }
 
-static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
 {
         struct kprobe *cur = kprobe_running();
         struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@@ -403,15 +403,6 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
                 if (post_kprobe_handler(args->regs))
                         ret = NOTIFY_STOP;
                 break;
-        case DIE_GPF:
-        case DIE_PAGE_FAULT:
-                /* kprobe_running() needs smp_processor_id() */
-                preempt_disable();
-                if (kprobe_running() &&
-                    kprobe_fault_handler(args->regs, args->trapnr))
-                        ret = NOTIFY_STOP;
-                preempt_enable();
-                break;
         default:
                 break;
         }
diff --git a/arch/sparc64/mm/fault.c b/arch/sparc64/mm/fault.c
index c32e309f7788..b582024d2199 100644
--- a/arch/sparc64/mm/fault.c
+++ b/arch/sparc64/mm/fault.c
@@ -32,36 +32,23 @@
 #include <asm/mmu_context.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)
+static inline int notify_page_fault(struct pt_regs *regs)
 {
-        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, const char *str,
-                        struct pt_regs *regs, long err, int trap, int sig)
-{
-        struct die_args args = {
-                .regs = regs,
-                .str = str,
-                .err = err,
-                .trapnr = trap,
-                .signr = sig
-        };
-        return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
+        int ret = 0;
+
+        /* kprobe_running() needs smp_processor_id() */
+        if (!user_mode(regs)) {
+                preempt_disable();
+                if (kprobe_running() && kprobe_fault_handler(regs, 0))
+                        ret = 1;
+                preempt_enable();
+        }
+        return ret;
 }
 #else
-static inline int notify_page_fault(enum die_val val, const char *str,
-                        struct pt_regs *regs, long err, int trap, int sig)
+static inline int notify_page_fault(struct pt_regs *regs)
 {
-        return NOTIFY_DONE;
+        return 0;
 }
 #endif
 
@@ -120,9 +107,6 @@ static void __kprobes unhandled_fault(unsigned long address,
         printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
                (tsk->mm ? (unsigned long) tsk->mm->pgd :
                           (unsigned long) tsk->active_mm->pgd));
-        if (notify_die(DIE_GPF, "general protection fault", regs,
-                       0, 0, SIGSEGV) == NOTIFY_STOP)
-                return;
         die_if_kernel("Oops", regs);
 }
 
@@ -299,8 +283,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
 
         fault_code = get_thread_fault_code();
 
-        if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs,
-                       fault_code, 0, SIGSEGV) == NOTIFY_STOP)
+        if (notify_page_fault(regs))
                 return;
 
         si_code = SEGV_MAPERR;
diff --git a/include/asm-sparc64/kdebug.h b/include/asm-sparc64/kdebug.h
index f8032e73f384..627e3396a5f0 100644
--- a/include/asm-sparc64/kdebug.h
+++ b/include/asm-sparc64/kdebug.h
@@ -7,8 +7,19 @@
 
 struct pt_regs;
 
-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 void bad_trap(struct pt_regs *, long);
 
@@ -20,7 +31,6 @@ enum die_val {
         DIE_DIE,
         DIE_TRAP,
         DIE_TRAP_TL1,
-        DIE_GPF,
         DIE_CALL,
         DIE_PAGE_FAULT,
 };
diff --git a/include/asm-sparc64/kprobes.h b/include/asm-sparc64/kprobes.h
index becc38fa06c5..a331b7b0dff2 100644
--- a/include/asm-sparc64/kprobes.h
+++ b/include/asm-sparc64/kprobes.h
@@ -43,4 +43,5 @@ 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 /* _SPARC64_KPROBES_H */