Merge branch 'master' into test

* master: (688 commits)
  dt-bindings: mailbox: qcom: Document the APCS clock binding
  mailbox: qcom: Create APCS child device for clock controller
  mailbox: qcom: Convert APCS IPC driver to use regmap
  KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL
  KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL
  KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
  KVM/x86: Add IBPB support
  KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX
  pinctrl: remove include file from <linux/device.h>
  firmware: dmi: handle missing DMI data gracefully
  firmware: dmi_scan: Fix handling of empty DMI strings
  firmware: dmi_scan: Drop dmi_initialized
  firmware: dmi: Optimize dmi_matches
  Revert "defer call to mem_cgroup_sk_alloc()"
  soreuseport: fix mem leak in reuseport_add_sock()
  net: qlge: use memmove instead of skb_copy_to_linear_data
  net: qed: use correct strncpy() size
  net: cxgb4: avoid memcpy beyond end of source buffer
  cls_u32: add missing RCU annotation.
  r8152: set rx mode early when linking on
  ...

1 files changed, 32 insertions, 1 deletions

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 17685e19aed8..78a647080ebc 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -3,10 +3,14 @@ menu "Kernel hacking"
 
 source "lib/Kconfig.debug"
 
-config ARM_PTDUMP
+config ARM_PTDUMP_CORE
+	def_bool n
+
+config ARM_PTDUMP_DEBUGFS
 	bool "Export kernel pagetable layout to userspace via debugfs"
 	depends on DEBUG_KERNEL
 	depends on MMU
+	select ARM_PTDUMP_CORE
 	select DEBUG_FS
 	---help---
 	  Say Y here if you want to show the kernel pagetable layout in a
@@ -16,6 +20,33 @@ config ARM_PTDUMP
 	  kernel.
 	  If in doubt, say "N"
 
+config DEBUG_WX
+	bool "Warn on W+X mappings at boot"
+	select ARM_PTDUMP_CORE
+	---help---
+		Generate a warning if any W+X mappings are found at boot.
+
+		This is useful for discovering cases where the kernel is leaving
+		W+X mappings after applying NX, as such mappings are a security risk.
+
+		Look for a message in dmesg output like this:
+
+			arm/mm: Checked W+X mappings: passed, no W+X pages found.
+
+		or like this, if the check failed:
+
+			arm/mm: Checked W+X mappings: FAILED, <N> W+X pages found.
+
+		Note that even if the check fails, your kernel is possibly
+		still fine, as W+X mappings are not a security hole in
+		themselves, what they do is that they make the exploitation
+		of other unfixed kernel bugs easier.
+
+		There is no runtime or memory usage effect of this option
+		once the kernel has booted up - it's a one time check.
+
+		If in doubt, say "Y".
+
 # RMK wants arm kernels compiled with frame pointers or stack unwinding.
 # If you know what you are doing and are willing to live without stack
 # traces, you can get a slightly smaller kernel by setting this option to