Revert: "powerpc/tm: Check for already reclaimed tasks"

This reverts commit e924c60db1b4891e45d15a33474ac5fab62cf029 which was
commit 7f821fc9c77a9b01fe7b1d6e72717b33d8d64142 upstream.

It shouldn't have been applied as the original was already in 4.4.

Reported-by: Jiri Slaby <jslaby@suse.cz>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ef2ad2d682dae74f97598fa4a789b59058368a29..646bf4d222c1caeda5c7851de74fbbe0ad0d65d9 100644 (file)
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -551,24 +551,6 @@ static void tm_reclaim_thread(struct thread_struct *thr,
                msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1;
        }
 
-       /*
-        * Use the current MSR TM suspended bit to track if we have
-        * checkpointed state outstanding.
-        * On signal delivery, we'd normally reclaim the checkpointed
-        * state to obtain stack pointer (see:get_tm_stackpointer()).
-        * This will then directly return to userspace without going
-        * through __switch_to(). However, if the stack frame is bad,
-        * we need to exit this thread which calls __switch_to() which
-        * will again attempt to reclaim the already saved tm state.
-        * Hence we need to check that we've not already reclaimed
-        * this state.
-        * We do this using the current MSR, rather tracking it in
-        * some specific thread_struct bit, as it has the additional
-        * benifit of checking for a potential TM bad thing exception.
-        */
-       if (!MSR_TM_SUSPENDED(mfmsr()))
-               return;
-
        /*
         * Use the current MSR TM suspended bit to track if we have
         * checkpointed state outstanding.