perf/x86: Fix USER/KERNEL tagging of samples

Several perf interrupt handlers (PEBS,IBS,BTS) re-write regs->ip but
do not update the segment registers. So use an regs->ip based test
instead of an regs->cs/regs->flags based test.
Reported-and-tested-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-xxrt0a1zronm1sm36obwc2vy@git.kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/perf_event.c

@@ -1863,7 +1863,7 @@ unsigned long perf_misc_flags(struct pt_regs *regs)
 		else
 			misc |= PERF_RECORD_MISC_GUEST_KERNEL;
 	} else {
-		if (user_mode(regs))
+		if (!kernel_ip(regs->ip))
 			misc |= PERF_RECORD_MISC_USER;
 		else
 			misc |= PERF_RECORD_MISC_KERNEL;