kprobes/x86: Move the get_kprobe_ctlblk() into irq-disabled block

Since get_kprobe_ctlblk() accesses per-cpu variables
which calls smp_processor_id(), it must be called under
preempt-disabled or irq-disabled.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/150581517952.32348.2655896843219158446.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 0cae7c0f32ec2dc363410ae798d9a5abe7f66e5f..f55810305f9a0b90a4c39922e5dd6101e0a3ecba 100644 (file)
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -154,7 +154,6 @@ STACK_FRAME_NON_STANDARD(optprobe_template_func);
 static void
 optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs)
 {
-       struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
        unsigned long flags;
 
        /* This is possible if op is under delayed unoptimizing */
@@ -165,6 +164,7 @@ optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs)
        if (kprobe_running()) {
                kprobes_inc_nmissed_count(&op->kp);
        } else {
+               struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
                /* Save skipped registers */
 #ifdef CONFIG_X86_64
                regs->cs = __KERNEL_CS;