X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=arch%2Fx86%2Fkernel%2Fkprobes.c;h=083848f0652cd8d1d065cc3e35faa5e5a64ddf92;hp=7da647d8b64cf1e4302510fd98d842ccdb123ad0;hb=3d8d613420a42dea7c12b990af3e81b98a31e809;hpb=d0411190377b3276a1fd573e6ef3802acbb899ea

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 7da647d8b64c..083848f0652c 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -1058,6 +1058,15 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
 	regs->flags &= ~X86_EFLAGS_IF;
 	trace_hardirqs_off();
 	regs->ip = (unsigned long)(jp->entry);
+
+	/*
+	 * jprobes use jprobe_return() which skips the normal return
+	 * path of the function, and this messes up the accounting of the
+	 * function graph tracer to get messed up.
+	 *
+	 * Pause function graph tracing while performing the jprobe function.
+	 */
+	pause_graph_tracing();
 	return 1;
 }
 
@@ -1083,24 +1092,25 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
 	u8 *addr = (u8 *) (regs->ip - 1);
 	struct jprobe *jp = container_of(p, struct jprobe, kp);
+	void *saved_sp = kcb->jprobe_saved_sp;
 
 	if ((addr > (u8 *) jprobe_return) &&
 	    (addr < (u8 *) jprobe_return_end)) {
-		if (stack_addr(regs) != kcb->jprobe_saved_sp) {
+		if (stack_addr(regs) != saved_sp) {
 			struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
 			printk(KERN_ERR
 			       "current sp %p does not match saved sp %p\n",
-			       stack_addr(regs), kcb->jprobe_saved_sp);
+			       stack_addr(regs), saved_sp);
 			printk(KERN_ERR "Saved registers for jprobe %p\n", jp);
 			show_registers(saved_regs);
 			printk(KERN_ERR "Current registers\n");
 			show_registers(regs);
 			BUG();
 		}
+		/* It's OK to start function graph tracing again */
+		unpause_graph_tracing();
 		*regs = kcb->jprobe_saved_regs;
-		memcpy((kprobe_opcode_t *)(kcb->jprobe_saved_sp),
-		       kcb->jprobes_stack,
-		       MIN_STACK_SIZE(kcb->jprobe_saved_sp));
+		memcpy(saved_sp, kcb->jprobes_stack, MIN_STACK_SIZE(saved_sp));
 		preempt_enable_no_resched();
 		return 1;
 	}