4 files changed, 15 insertions, 24 deletions

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 4daf8c501239..0a3f9c9f98d5 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -5,6 +5,7 @@
 #include <linux/stddef.h>
 #include <linux/stringify.h>
 #include <asm/asm.h>
+#include <asm/ptrace.h>
 
 /*
  * Alternative inline assembly for SMP.
@@ -224,6 +225,7 @@ extern void *text_poke_early(void *addr, const void *opcode, size_t len);
  * inconsistent instruction while you patch.
  */
 extern void *text_poke(void *addr, const void *opcode, size_t len);
+extern int poke_int3_handler(struct pt_regs *regs);
 extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);
 
 #endif /* _ASM_X86_ALTERNATIVE_H */
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5d8782ee3dd7..15e8563e5c24 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -605,26 +605,24 @@ static void do_sync_core(void *info)
 static bool bp_patching_in_progress;
 static void *bp_int3_handler, *bp_int3_addr;
 
-static int int3_notify(struct notifier_block *self, unsigned long val, void *data)
+int poke_int3_handler(struct pt_regs *regs)
 {
-        struct die_args *args = data;
-
         /* bp_patching_in_progress */
         smp_rmb();
 
         if (likely(!bp_patching_in_progress))
-                return NOTIFY_DONE;
+                return 0;
 
-        /* we are not interested in non-int3 faults and ring > 0 faults */
-        if (val != DIE_INT3 || !args->regs || user_mode_vm(args->regs)
-                            || args->regs->ip != (unsigned long)bp_int3_addr)
-                return NOTIFY_DONE;
+        if (user_mode_vm(regs) || regs->ip != (unsigned long)bp_int3_addr)
+                return 0;
 
         /* set up the specified breakpoint handler */
-        args->regs->ip = (unsigned long) bp_int3_handler;
+        regs->ip = (unsigned long) bp_int3_handler;
+
+        return 1;
 
-        return NOTIFY_STOP;
 }
+
 /**
  * text_poke_bp() -- update instructions on live kernel on SMP
  * @addr:       address to patch
@@ -689,16 +687,3 @@ void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler)
         return addr;
 }
 
-/* this one needs to run before anything else handles it as a
- * regular exception */
-static struct notifier_block int3_nb = {
-        .priority = 0x7fffffff,
-        .notifier_call = int3_notify
-};
-
-static int __init int3_init(void)
-{
-        return register_die_notifier(&int3_nb);
-}
-
-arch_initcall(int3_init);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 1b23a1c92746..8c8093b146ca 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -58,6 +58,7 @@
 #include <asm/mce.h>
 #include <asm/fixmap.h>
 #include <asm/mach_traps.h>
+#include <asm/alternative.h>
 
 #ifdef CONFIG_X86_64
 #include <asm/x86_init.h>
@@ -327,6 +328,9 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
             ftrace_int3_handler(regs))
                 return;
 #endif
+        if (poke_int3_handler(regs))
+                return;
+
         prev_state = exception_enter();
 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
         if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index b58b490fa439..6e33498d665c 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1709,7 +1709,7 @@ EXPORT_SYMBOL_GPL(unregister_kprobes);
 
 static struct notifier_block kprobe_exceptions_nb = {
         .notifier_call = kprobe_exceptions_notify,
-        .priority = 0x7ffffff0 /* High priority, but not first.  */
+        .priority = 0x7fffffff /* we need to be notified first */
 };
 
 unsigned long __weak arch_deref_entry_point(void *entry)