x86/hw-breakpoints: Optimize return code from notifier chain in hw_breakpoint_handler

[pandora-kernel.git] / arch / x86 / kernel / hw_breakpoint.c

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 05d5fec..ae90b47 100644 (file)
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -502,8 +502,6 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args)
                rcu_read_lock();
 
                bp = per_cpu(bp_per_reg[i], cpu);
-               if (bp)
-                       rc = NOTIFY_DONE;
                /*
                 * Reset the 'i'th TRAP bit in dr6 to denote completion of
                 * exception handling
@@ -522,7 +520,13 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args)
 
                rcu_read_unlock();
        }
-       if (dr6 & (~DR_TRAP_BITS))
+       /*
+        * Further processing in do_debug() is needed for a) user-space
+        * breakpoints (to generate signals) and b) when the system has
+        * taken exception due to multiple causes
+        */
+       if ((current->thread.debugreg6 & DR_TRAP_BITS) ||
+           (dr6 & (~DR_TRAP_BITS)))
                rc = NOTIFY_DONE;
 
        set_debugreg(dr7, 7);