arm64: el0_dbg does not set link reg for return to user path, breaks debugv3.14/topic/nohz

When the context tracking feature was backported to 3.14 LSK,
setting of the LR was moved out of the main body of el0_sync
and into the applicable sub handlers (i.e. el0_da, el0_sp_pc,
etc).  The el0_dbg handler was overlooked.  The implication
is that do_debug_exception() will attempt to return directly
to userspace without going through the ret_from_exception
path.  This ultimately results in another sync exception due
to a protection fault on the target PC.

This was introduced by:

    commit 333625b7586d2753a77f32e1f898ab7cc6cf7655
    Author: Larry Bassel <larry.bassel@linaro.org>
    Date:   Wed Oct 15 15:15:56 2014 -0700

        arm64: adjust el0_sync so that a function can be called

        Backport of the following patch to 3.14 LSK:

        commit 6ab6463aeb5fbc75fa3227befb508fc33b34dbf1
        Author: Larry Bassel <larry.bassel@linaro.org>
        Date:   Fri May 30 20:34:14 2014 +0100

Signed-off-by: Luke Starrett <lstarret@broadcom.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>

0 files changed, 0 insertions, 0 deletions