1 files changed, 44 insertions, 0 deletions

diff --git a/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.7/0016-writeback-fix-dereferencing-NULL-bdi-dev-on-trace_wr.patch b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.7/0016-writeback-fix-dereferencing-NULL-bdi-dev-on-trace_wr.patch
new file mode 100644
index 00000000..495dfa8d
--- /dev/null
+++ b/recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.7/0016-writeback-fix-dereferencing-NULL-bdi-dev-on-trace_wr.patch
@@ -0,0 +1,44 @@
+From 422204b77968331ce85721527f7ece49f72658f2 Mon Sep 17 00:00:00 2001
+From: Wu Fengguang <fengguang.wu@intel.com>
+Date: Sat, 4 Feb 2012 20:54:03 -0600
+Subject: [PATCH 16/30] writeback: fix dereferencing NULL bdi->dev on
+ trace_writeback_queue
+
+commit 977b7e3a52a7421ad33a393a38ece59f3d41c2fa upstream.
+
+When a SD card is hot removed without umount, del_gendisk() will call
+bdi_unregister() without destroying/freeing it. This leaves the bdi in
+the bdi->dev = NULL, bdi->wb.task = NULL, bdi->bdi_list removed state.
+
+When sync(2) gets the bdi before bdi_unregister() and calls
+bdi_queue_work() after the unregister, trace_writeback_queue will be
+dereferencing the NULL bdi->dev. Fix it with a simple test for NULL.
+
+LKML-reference: http://lkml.org/lkml/2012/1/18/346
+Reported-by: Rabin Vincent <rabin@rab.in>
+Tested-by: Namjae Jeon <linkinjeon@gmail.com>
+Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/trace/events/writeback.h |    5 ++++-
+ 1 files changed, 4 insertions(+), 1 deletions(-)
+
+diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
+index 46e389c..1f48f14 100644
+--- a/include/trace/events/writeback.h
++++ b/include/trace/events/writeback.h
+@@ -47,7 +47,10 @@ DECLARE_EVENT_CLASS(writeback_work_class,
+                __field(int, reason)
+        ),
+        TP_fast_assign(
+-               strncpy(__entry->name, dev_name(bdi->dev), 32);
++               struct device *dev = bdi->dev;
++               if (!dev)
++                       dev = default_backing_dev_info.dev;
++               strncpy(__entry->name, dev_name(dev), 32);
+                __entry->nr_pages = work->nr_pages;
+                __entry->sb_dev = work->sb ? work->sb->s_dev : 0;
+                __entry->sync_mode = work->sync_mode;
+-- 
+1.7.7.4
+