Merge branch 'mm-readonly-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull read-only kernel memory updates from Ingo Molnar:
 "This tree adds two (security related) enhancements to the kernel's
  handling of read-only kernel memory:

   - extend read-only kernel memory to a new class of formerly writable
     kernel data: 'post-init read-only memory' via the __ro_after_init
     attribute, and mark the ARM and x86 vDSO as such read-only memory.

     This kind of attribute can be used for data that requires a once
     per bootup initialization sequence, but is otherwise never modified
     after that point.

     This feature was based on the work by PaX Team and Brad Spengler.

     (by Kees Cook, the ARM vDSO bits by David Brown.)

   - make CONFIG_DEBUG_RODATA always enabled on x86 and remove the
     Kconfig option.  This simplifies the kernel and also signals that
     read-only memory is the default model and a first-class citizen.
     (Kees Cook)"

* 'mm-readonly-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ARM/vdso: Mark the vDSO code read-only after init
  x86/vdso: Mark the vDSO code read-only after init
  lkdtm: Verify that '__ro_after_init' works correctly
  arch: Introduce post-init read-only memory
  x86/mm: Always enable CONFIG_DEBUG_RODATA and remove the Kconfig option
  mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings
  asm-generic: Consolidate mark_rodata_ro()

1 files changed, 3 insertions, 15 deletions

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 9b18ed97a8a2..7816b7b276f4 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -74,28 +74,16 @@ config EFI_PGT_DUMP
 	  issues with the mapping of the EFI runtime regions into that
 	  table.
 
-config DEBUG_RODATA
-	bool "Write protect kernel read-only data structures"
-	default y
-	depends on DEBUG_KERNEL
-	---help---
-	  Mark the kernel read-only data as write-protected in the pagetables,
-	  in order to catch accidental (and incorrect) writes to such const
-	  data. This is recommended so that we can catch kernel bugs sooner.
-	  If in doubt, say "Y".
-
 config DEBUG_RODATA_TEST
-	bool "Testcase for the DEBUG_RODATA feature"
-	depends on DEBUG_RODATA
+	bool "Testcase for the marking rodata read-only"
 	default y
 	---help---
-	  This option enables a testcase for the DEBUG_RODATA
-	  feature as well as for the change_page_attr() infrastructure.
+	  This option enables a testcase for the setting rodata read-only
+	  as well as for the change_page_attr() infrastructure.
 	  If in doubt, say "N"
 
 config DEBUG_WX
 	bool "Warn on W+X mappings at boot"
-	depends on DEBUG_RODATA
 	select X86_PTDUMP_CORE
 	---help---
 	  Generate a warning if any W+X mappings are found at boot.