Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

1 files changed, 10 insertions, 18 deletions

diff --git a/kernel/arch/powerpc/kernel/process.c b/kernel/arch/powerpc/kernel/process.c
index ef2ad2d68..cf788d7d7 100644
--- a/kernel/arch/powerpc/kernel/process.c
+++ b/kernel/arch/powerpc/kernel/process.c
@@ -569,24 +569,6 @@ static void tm_reclaim_thread(struct thread_struct *thr,
 	if (!MSR_TM_SUSPENDED(mfmsr()))
 		return;
 
-	/*
-	 * 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;
-
 	tm_reclaim(thr, thr->regs->msr, cause);
 
 	/* Having done the reclaim, we now have the checkpointed
@@ -1257,6 +1239,16 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 		current->thread.regs = regs - 1;
 	}
 
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	/*
+	 * Clear any transactional state, we're exec()ing. The cause is
+	 * not important as there will never be a recheckpoint so it's not
+	 * user visible.
+	 */
+	if (MSR_TM_SUSPENDED(mfmsr()))
+		tm_reclaim_current(0);
+#endif
+
 	memset(regs->gpr, 0, sizeof(regs->gpr));
 	regs->ctr = 0;
 	regs->link = 0;