Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "Once again, Catalin's off on holiday and I'm looking after the arm64
  tree.  Please can you pull the following arm64 updates for 3.17?

  Note that this branch also includes the new GICv3 driver (merged via a
  stable tag from Jason's irqchip tree), since there is a fix for older
  binutils on top.

  Changes include:
   - context tracking support (NO_HZ_FULL) which narrowly missed 3.16
   - vDSO layout rework following Andy's work on x86
   - TEXT_OFFSET fuzzing for bootloader testing
   - /proc/cpuinfo tidy-up
   - preliminary work to support 48-bit virtual addresses, but this is
     currently disabled until KVM has been ported to use it (the patches
     do, however, bring some nice clean-up)
   - boot-time CPU sanity checks (especially useful on heterogenous
     systems)
   - support for syscall auditing
   - support for CC_STACKPROTECTOR
   - defconfig updates"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (55 commits)
  arm64: add newline to I-cache policy string
  Revert "arm64: dmi: Add SMBIOS/DMI support"
  arm64: fpsimd: fix a typo in fpsimd_save_partial_state ENDPROC
  arm64: don't call break hooks for BRK exceptions from EL0
  arm64: defconfig: enable devtmpfs mount option
  arm64: vdso: fix build error when switching from LE to BE
  arm64: defconfig: add virtio support for running as a kvm guest
  arm64: gicv3: Allow GICv3 compilation with older binutils
  arm64: fix soft lockup due to large tlb flush range
  arm64/crypto: fix makefile rule for aes-glue-%.o
  arm64: Do not invoke audit_syscall_* functions if !CONFIG_AUDIT_SYSCALL
  arm64: Fix barriers used for page table modifications
  arm64: Add support for 48-bit VA space with 64KB page configuration
  arm64: asm/pgtable.h pmd/pud definitions clean-up
  arm64: Determine the vmalloc/vmemmap space at build time based on VA_BITS
  arm64: Clean up the initial page table creation in head.S
  arm64: Remove asm/pgtable-*level-types.h files
  arm64: Remove asm/pgtable-*level-hwdef.h files
  arm64: Convert bool ARM64_x_LEVELS to int ARM64_PGTABLE_LEVELS
  arm64: mm: Implement 4 levels of translation tables
  ...

1 files changed, 38 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/stackprotector.h b/arch/arm64/include/asm/stackprotector.h
new file mode 100644
index 000000000000..fe5e287dc56b
--- /dev/null
+++ b/arch/arm64/include/asm/stackprotector.h
@@ -0,0 +1,38 @@
+/*
+ * GCC stack protector support.
+ *
+ * Stack protector works by putting predefined pattern at the start of
+ * the stack frame and verifying that it hasn't been overwritten when
+ * returning from the function.  The pattern is called stack canary
+ * and gcc expects it to be defined by a global variable called
+ * "__stack_chk_guard" on ARM.  This unfortunately means that on SMP
+ * we cannot have a different canary value per task.
+ */
+
+#ifndef __ASM_STACKPROTECTOR_H
+#define __ASM_STACKPROTECTOR_H
+
+#include <linux/random.h>
+#include <linux/version.h>
+
+extern unsigned long __stack_chk_guard;
+
+/*
+ * 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)
+{
+	unsigned long canary;
+
+	/* Try to get a semi random initial value. */
+	get_random_bytes(&canary, sizeof(canary));
+	canary ^= LINUX_VERSION_CODE;
+
+	current->stack_canary = canary;
+	__stack_chk_guard = current->stack_canary;
+}
+
+#endif	/* _ASM_STACKPROTECTOR_H */