On Thu, Oct 13, 2011 at 03:11:37PM +0530, Ananth N Mavinakayanahalli wrote:

On Thu, Oct 13, 2011 at 02:37:49PM +0530, Maneesh Soni wrote:

...

I know nothing of MIPS internals, but...
 

quoted

 static int __kprobes kprobe_handler(struct pt_regs *regs)

@@ -239,8 +531,13 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
 			save_previous_kprobe(kcb);
 			set_current_kprobe(p, regs, kcb);
 			kprobes_inc_nmissed_count(p);
-			prepare_singlestep(p, regs);
+			prepare_singlestep(p, regs, kcb);
 			kcb->kprobe_status = KPROBE_REENTER;
+			if (kcb->flags & SKIP_DELAYSLOT) {
+				resume_execution(p, regs, kcb);
+				restore_previous_kprobe(kcb);
+				preempt_enable_no_resched();
+			}
 			return 1;
 		} else {
 			if (addr->word != breakpoint_insn.word) {

@@ -284,8 +581,15 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
 	}

 ss_probe:
-	prepare_singlestep(p, regs);
-	kcb->kprobe_status = KPROBE_HIT_SS;
+	prepare_singlestep(p, regs, kcb);
+	if (kcb->flags & SKIP_DELAYSLOT) {
+		kcb->kprobe_status = KPROBE_HIT_SSDONE;
+		if (p->post_handler)
+			p->post_handler(p, regs, 0);
+		resume_execution(p, regs, kcb);

You are missing a preempt_disable_no_resched() here.

Oops! I meant preempt_enable_no_resched().

Ananth