[PATCH tip/core/urgent] Fix for hlist_entry_safe() regression

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

Hello, Ingo

This series contains a single commit that fixes a regression in
hlist_entry_safe().  This macro references its argument twice, which
can cause NULL-pointer errors.  This commit applies a gcc statement
expression, creating a temporary variable to avoid the double reference.
This has been posted to LKML at https://lkml.org/lkml/2013/3/9/75.

Kudos to CAI Qian, whose testing uncovered this, to Eric Dumazet, who
spotted root cause, and to Li Zefan, who tested this commit.

This commit is available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/urgent

							Thanx, Paul

----------------------------------------------------------------
Paul E. McKenney (1):
      list: Fix double fetch of pointer in hlist_entry_safe()

 include/linux/list.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)