Merge commit 'remotes/tip/x86/paravirt' into x86/untangle2

* commit 'remotes/tip/x86/paravirt': (175 commits)
  xen: use direct ops on 64-bit
  xen: make direct versions of irq_enable/disable/save/restore to common code
  xen: setup percpu data pointers
  xen: fix 32-bit build resulting from mmu move
  x86/paravirt: return full 64-bit result
  x86, percpu: fix kexec with vmlinux
  x86/vmi: fix interrupt enable/disable/save/restore calling convention.
  x86/paravirt: don't restore second return reg
  xen: setup percpu data pointers
  x86: split loading percpu segments from loading gdt
  x86: pass in cpu number to switch_to_new_gdt()
  x86: UV fix uv_flush_send_and_wait()
  x86/paravirt: fix missing callee-save call on pud_val
  x86/paravirt: use callee-saved convention for pte_val/make_pte/etc
  x86/paravirt: implement PVOP_CALL macros for callee-save functions
  x86/paravirt: add register-saving thunks to reduce caller register pressure
  x86/paravirt: selectively save/restore regs around pvops calls
  x86: fix paravirt clobber in entry_64.S
  x86/pvops: add a paravirt_ident functions to allow special patching
  xen: move remaining mmu-related stuff into mmu.c
  ...

Conflicts:
	arch/x86/mach-voyager/voyager_smp.c
	arch/x86/mm/fault.c

1 files changed, 38 insertions, 0 deletions

diff --git a/arch/x86/include/asm/stackprotector.h b/arch/x86/include/asm/stackprotector.h
new file mode 100644
index 00000000000..36a700acaf2
--- /dev/null
+++ b/arch/x86/include/asm/stackprotector.h
@@ -0,0 +1,38 @@
+#ifndef _ASM_STACKPROTECTOR_H
+#define _ASM_STACKPROTECTOR_H 1
+
+#include <asm/tsc.h>
+#include <asm/processor.h>
+
+/*
+ * Initialize the stackprotector canary value.
+ *
+ * NOTE: this must only be called from functions that never return,
+ * and it must always be inlined.
+ */
+static __always_inline void boot_init_stack_canary(void)
+{
+	u64 canary;
+	u64 tsc;
+
+	/*
+	 * Build time only check to make sure the stack_canary is at
+	 * offset 40 in the pda; this is a gcc ABI requirement
+	 */
+	BUILD_BUG_ON(offsetof(union irq_stack_union, stack_canary) != 40);
+
+	/*
+	 * We both use the random pool and the current TSC as a source
+	 * of randomness. The TSC only matters for very early init,
+	 * there it already has some randomness on most systems. Later
+	 * on during the bootup the random pool has true entropy too.
+	 */
+	get_random_bytes(&canary, sizeof(canary));
+	tsc = __native_read_tsc();
+	canary += tsc + (tsc << 32UL);
+
+	current->stack_canary = canary;
+	percpu_write(irq_stack_union.stack_canary, canary);
+}
+
+#endif