ftrace: mark lapic_wd_event() notrace

it can be called in the NMI path:

[    0.645999] calling  ftrace_dynamic_init+0x0/0xd6
[    0.647521] ------------[ cut here ]------------
[    0.647521] WARNING: at kernel/trace/ftrace.c:348 ftrace_record_ip+0x4e/0x252()
[    0.647521] Modules linked in:
[    0.647521] Pid: 15, comm: kstop1 Not tainted 2.6.27-rc1-tip #22686
[    0.647521]
[    0.647521] Call Trace:
[    0.647521]  <NMI>  [<ffffffff8024593f>] warn_on_slowpath+0x5d/0x84
[    0.647521]  [<ffffffff80220b99>] ? lapic_wd_event+0xb/0x5c
[    0.647521]  [<ffffffff80287b3b>] ftrace_record_ip+0x4e/0x252
[    0.647521]  [<ffffffff80211274>] mcount_call+0x5/0x31
[    0.647521]  [<ffffffff80220b9e>] ? lapic_wd_event+0x10/0x5c
[    0.647521]  [<ffffffff8083f3ec>] nmi_watchdog_tick+0x19d/0x1ad
[    0.647521]  [<ffffffff8083e875>] default_do_nmi+0x75/0x1e3
[    0.647521]  [<ffffffff8083f0b3>] do_nmi+0x5d/0x94
[    0.647521]  [<ffffffff8083e2d2>] nmi+0xa2/0xc2
[    0.647521]  [<ffffffff802b48c3>] ? check_bytes_and_report+0x11/0xcc
[    0.647521]  <<EOE>>  [<ffffffff80211274>] ? mcount_call+0x5/0x31
[    0.647521]  [<ffffffff802b49df>] check_object+0x61/0x1b0
[    0.647521]  [<ffffffff802b502a>] __slab_free+0x169/0x2ae
[    0.647521]  [<ffffffff80242dbf>] ? __cleanup_sighand+0x25/0x27
[    0.647521]  [<ffffffff80242dbf>] ? __cleanup_sighand+0x25/0x27
[    0.647521]  [<ffffffff802b60cd>] kmem_cache_free+0x85/0xb9
[    0.647521]  [<ffffffff80242dbf>] __cleanup_sighand+0x25/0x27
[    0.647521]  [<ffffffff80247b3d>] release_task+0x256/0x339
[    0.647521]  [<ffffffff802490b4>] do_exit+0x764/0x7ef
[    0.647521]  [<ffffffff8027624c>] __xchg+0x0/0x38
[    0.647521]  [<ffffffff8027619a>] ? stop_cpu+0x0/0xb2
[    0.647521]  [<ffffffff8027619a>] ? stop_cpu+0x0/0xb2
[    0.647521]  [<ffffffff8025922f>] kthread+0x4e/0x7b
[    0.647521]  [<ffffffff80212979>] child_rip+0xa/0x11
[    0.647521]  [<ffffffff80211c17>] ? restore_args+0x0/0x30
[    0.647521]  [<ffffffff802283a5>] ? native_load_tls+0x14/0x2e
[    0.647521]  [<ffffffff802591e1>] ? kthread+0x0/0x7b
[    0.647521]  [<ffffffff8021296f>] ? child_rip+0x0/0x11
[    0.647521]
[    0.647521] ---[ end trace 4eaa2a86a8e2da22 ]---
[    0.672032] initcall ftrace_dynamic_init+0x0/0xd6 returned 0 after 19 msecs

also mark it no-kprobes while at it.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/cpu/perfctr-watchdog.c

@@ -17,6 +17,8 @@
 #include <linux/bitops.h>
 #include <linux/smp.h>
 #include <linux/nmi.h>
+#include <linux/kprobes.h>
+
 #include <asm/apic.h>
 #include <asm/intel_arch_perfmon.h>
 
@@ -336,7 +338,8 @@ static void single_msr_unreserve(void)
 	release_perfctr_nmi(wd_ops->perfctr);
 }
 
-static void single_msr_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
+static void __kprobes
+single_msr_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
 {
 	/* start the cycle over again */
 	write_watchdog_counter(wd->perfctr_msr, NULL, nmi_hz);
@@ -401,7 +404,7 @@ static int setup_p6_watchdog(unsigned nmi_hz)
 	return 1;
 }
 
-static void p6_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
+static void __kprobes p6_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
 {
 	/*
 	 * P6 based Pentium M need to re-unmask
@@ -605,7 +608,7 @@ static void p4_unreserve(void)
 	release_perfctr_nmi(MSR_P4_IQ_PERFCTR0);
 }
 
-static void p4_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
+static void __kprobes p4_rearm(struct nmi_watchdog_ctlblk *wd, unsigned nmi_hz)
 {
 	unsigned dummy;
 	/*
@@ -784,7 +787,7 @@ unsigned lapic_adjust_nmi_hz(unsigned hz)
 	return hz;
 }
 
-int lapic_wd_event(unsigned nmi_hz)
+int __kprobes lapic_wd_event(unsigned nmi_hz)
 {
 	struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
 	u64 ctr;