Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
ftrace: handle archs that do not support irqs_disabled_flags

Documentation/ftrace.txt

···
   CPU#: The CPU which the process was running on.
 
   irqs-off: 'd' interrupts are disabled. '.' otherwise.
+	    Note: If the architecture does not support a way to
+		  read the irq flags variable, an 'X' will always
+		  be printed here.
 
   need-resched: 'N' task need_resched is set, '.' otherwise.
 

kernel/trace/trace.c

···
 	entry->preempt_count		= pc & 0xff;
 	entry->pid			= (tsk) ? tsk->pid : 0;
 	entry->flags =
+#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
 		(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+#else
+		TRACE_FLAG_IRQS_NOSUPPORT |
+#endif
 		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
 		((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
 		(need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
···
 	trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
 	trace_seq_printf(s, "%3d", cpu);
 	trace_seq_printf(s, "%c%c",
-			(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
+			(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' :
+			 (entry->flags & TRACE_FLAG_IRQS_NOSUPPORT) ? 'X' : '.',
 			((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
 
 	hardirq = entry->flags & TRACE_FLAG_HARDIRQ;

kernel/trace/trace.h

···
 /*
  * trace_flag_type is an enumeration that holds different
  * states when a trace occurs. These are:
- *  IRQS_OFF	- interrupts were disabled
- *  NEED_RESCED - reschedule is requested
- *  HARDIRQ	- inside an interrupt handler
- *  SOFTIRQ	- inside a softirq handler
- *  CONT	- multiple entries hold the trace item
+ *  IRQS_OFF		- interrupts were disabled
+ *  IRQS_NOSUPPORT 	- arch does not support irqs_disabled_flags
+ *  NEED_RESCED		- reschedule is requested
+ *  HARDIRQ		- inside an interrupt handler
+ *  SOFTIRQ		- inside a softirq handler
+ *  CONT		- multiple entries hold the trace item
  */
 enum trace_flag_type {
 	TRACE_FLAG_IRQS_OFF		= 0x01,
-	TRACE_FLAG_NEED_RESCHED		= 0x02,
-	TRACE_FLAG_HARDIRQ		= 0x04,
-	TRACE_FLAG_SOFTIRQ		= 0x08,
-	TRACE_FLAG_CONT			= 0x10,
+	TRACE_FLAG_IRQS_NOSUPPORT	= 0x02,
+	TRACE_FLAG_NEED_RESCHED		= 0x04,
+	TRACE_FLAG_HARDIRQ		= 0x08,
+	TRACE_FLAG_SOFTIRQ		= 0x10,
+	TRACE_FLAG_CONT			= 0x20,
 };
 
 #define TRACE_BUF_SIZE		1024