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, 13 insertions, 0 deletions

diff --git a/kernel/arch/x86/kvm/irq_comm.c b/kernel/arch/x86/kvm/irq_comm.c
index 84b96d319..d09544e82 100644
--- a/kernel/arch/x86/kvm/irq_comm.c
+++ b/kernel/arch/x86/kvm/irq_comm.c
@@ -38,6 +38,15 @@ static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
 			   bool line_status)
 {
 	struct kvm_pic *pic = pic_irqchip(kvm);
+
+	/*
+	 * XXX: rejecting pic routes when pic isn't in use would be better,
+	 * but the default routing table is installed while kvm->arch.vpic is
+	 * NULL and KVM_CREATE_IRQCHIP can race with KVM_IRQ_LINE.
+	 */
+	if (!pic)
+		return -1;
+
 	return kvm_pic_set_irq(pic, e->irqchip.pin, irq_source_id, level);
 }
 
@@ -46,6 +55,10 @@ static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
 			      bool line_status)
 {
 	struct kvm_ioapic *ioapic = kvm->arch.vioapic;
+
+	if (!ioapic)
+		return -1;
+
 	return kvm_ioapic_set_irq(ioapic, e->irqchip.pin, irq_source_id, level,
 				line_status);
 }