Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH] writeback: verify that underlying dev exists before getting its name | Date | Fri, 4 Sep 2015 12:45:18 -0400 |
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We can't assume there is always an underlying device and must verify that as well. Otherwise, we'd deref a NULL ptr here.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com> --- include/trace/events/writeback.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index fff846b..8f9efaa 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -66,7 +66,9 @@ TRACE_EVENT(writeback_dirty_page, TP_fast_assign( strncpy(__entry->name, - mapping ? dev_name(inode_to_bdi(mapping->host)->dev) : "(unknown)", 32); + mapping && inode_to_bdi(mapping->host)->dev ? + dev_name(inode_to_bdi(mapping->host)->dev) : + "(unknown)", 32); __entry->ino = mapping ? mapping->host->i_ino : 0; __entry->index = page->index; ), -- 1.7.10.4
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