From: Steven Rostedt Date: Tue, 20 Dec 2011 00:07:36 +0000 (-0500) Subject: ftrace: Create ftrace_hash_empty() helper routine X-Git-Tag: v3.2.54~4 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=195c821e74fc44042a86f9d7f101dc6f03a826b1;p=pandora-kernel.git ftrace: Create ftrace_hash_empty() helper routine commit 06a51d9307380c78bb5c92e68fc80ad2c7d7f890 upstream. There are two types of hashes in the ftrace_ops; one type is the filter_hash and the other is the notrace_hash. Either one may be null, meaning it has no elements. But when elements are added, the hash is allocated. Throughout the code, a check needs to be made to see if a hash exists or the hash has elements, but the check if the hash exists is usually missing causing the possible "NULL pointer dereference bug". Add a helper routine called "ftrace_hash_empty()" that returns true if the hash doesn't exist or its count is zero. As they mean the same thing. Last-bug-reported-by: Jiri Olsa Signed-off-by: Steven Rostedt Signed-off-by: Ben Hutchings --- Reading git-diff-tree failed