tracing: Don't call page_to_pfn() if page is NULL
Wen Congyang [Thu, 20 Sep 2012 06:04:47 +0000 (14:04 +0800)]
commit 85f2a2ef1d0ab99523e0b947a2b723f5650ed6aa upstream.

When allocating memory fails, page is NULL. page_to_pfn() will
cause the kernel panicked if we don't use sparsemem vmemmap.

Link: http://lkml.kernel.org/r/505AB1FF.8020104@cn.fujitsu.com

Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/trace/events/kmem.h

index 5f889f1..08fa272 100644 (file)
@@ -214,7 +214,7 @@ TRACE_EVENT(mm_page_alloc,
 
        TP_printk("page=%p pfn=%lu order=%d migratetype=%d gfp_flags=%s",
                __entry->page,
-               page_to_pfn(__entry->page),
+               __entry->page ? page_to_pfn(__entry->page) : 0,
                __entry->order,
                __entry->migratetype,
                show_gfp_flags(__entry->gfp_flags))
@@ -240,7 +240,7 @@ DECLARE_EVENT_CLASS(mm_page,
 
        TP_printk("page=%p pfn=%lu order=%u migratetype=%d percpu_refill=%d",
                __entry->page,
-               page_to_pfn(__entry->page),
+               __entry->page ? page_to_pfn(__entry->page) : 0,
                __entry->order,
                __entry->migratetype,
                __entry->order == 0)