[GIT PULL] x86 fixes

[Ingo Molnar]

Linus,

Please pull the latest x86-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
x86-urgent-for-linus

   # HEAD: 1bdb8970392a68489b469c3a330a1adb5ef61beb x86/apic: Handle zero 
vector gracefully in clear_vector_irq()

Two boot crash fixes and an IRQ handling crash fix.

 Thanks,

        Ingo

------------------>
Andy Lutomirski (1):
      Revert "x86/mm/32: Set NX in __supported_pte_mask before enabling paging"

Keith Busch (1):
      x86/apic: Handle zero vector gracefully in clear_vector_irq()

Ross Lagerwall (1):
      xen/qspinlock: Don't kick CPU if IRQ is not initialized


 arch/x86/kernel/apic/vector.c | 3 ++-
 arch/x86/kernel/head_32.S     | 6 ------
 arch/x86/mm/setup_nx.c        | 5 +++--
 arch/x86/xen/spinlock.c       | 6 ++++++
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index ad59d70bcb1a..ef495511f019 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -256,7 +256,8 @@ static void clear_irq_vector(int irq, struct apic_chip_data 
*data)
        struct irq_desc *desc;
        int cpu, vector;
 
-       BUG_ON(!data->cfg.vector);
+       if (!data->cfg.vector)
+               return;
 
        vector = data->cfg.vector;
        for_each_cpu_and(cpu, data->domain, cpu_online_mask)
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 54cdbd2003fe..af1112980dd4 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -389,12 +389,6 @@ ENTRY(startup_32_smp)
        /* Make changes effective */
        wrmsr
 
-       /*
-        * And make sure that all the mappings we set up have NX set from
-        * the beginning.
-        */
-       orl $(1 << (_PAGE_BIT_NX - 32)), pa(__supported_pte_mask + 4)
-
 enable_paging:
 
 /*
diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c
index 8bea84724a7d..f65a33f505b6 100644
--- a/arch/x86/mm/setup_nx.c
+++ b/arch/x86/mm/setup_nx.c
@@ -32,8 +32,9 @@ early_param("noexec", noexec_setup);
 
 void x86_configure_nx(void)
 {
-       /* If disable_nx is set, clear NX on all new mappings going forward. */
-       if (disable_nx)
+       if (boot_cpu_has(X86_FEATURE_NX) && !disable_nx)
+               __supported_pte_mask |= _PAGE_NX;
+       else
                __supported_pte_mask &= ~_PAGE_NX;
 }
 
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c
index 9e2ba5c6e1dd..f42e78de1e10 100644
--- a/arch/x86/xen/spinlock.c
+++ b/arch/x86/xen/spinlock.c
@@ -27,6 +27,12 @@ static bool xen_pvspin = true;
 
 static void xen_qlock_kick(int cpu)
 {
+       int irq = per_cpu(lock_kicker_irq, cpu);
+
+       /* Don't kick if the target's kicker interrupt is not initialized. */
+       if (irq == -1)
+               return;
+
        xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR);
 }