tree 56ac5f64371ae0a41e2548736baa1851f1b2f522
parent 55e4341850ac56e63a3eefe9583a9000042164fa
author Michael Neuling <mikey@neuling.org> 1370776999 +1000
committer Benjamin Herrenschmidt <benh@kernel.crashing.org> 1371711928 +1000

powerpc/tm: Fix return of active 64bit signals

Currently we only restore signals which are transactionally suspended but it's
possible that the transaction can be restored even when it's active.  Most
likely this will result in a transactional rollback by the hardware as the
transaction will have been doomed by an earlier treclaim.

The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel.  That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
assumptions based on having software rollback.

This changes the signal return code to always restore both contexts on 64 bit
signal return.  It also ensures that the MSR TM bits are properly restored from
the signal context which they are not currently.

Signed-off-by: Michael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>