Merge tag 'gcc-plugins-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...

Pull gcc-plugins updates from Kees Cook:
 "This adds additional type coverage to the existing structleak plugin
  and adds a large set of selftests to help evaluate stack variable
  zero-initialization coverage.

  That can be used to test whatever instrumentation might be performing
  zero-initialization: either with the structleak plugin or with Clang's
  coming "-ftrivial-auto-var-init=zero" option.

  Summary:

   - Add scalar and array initialization coverage

   - Refactor Kconfig to make options more clear

   - Add self-test module for testing automatic initialization"

* tag 'gcc-plugins-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  lib: Introduce test_stackinit module
  gcc-plugins: structleak: Generalize to all variable types

diff --cc lib/Kconfig.debug
index d765d36f8737581d630a4cc84e009265680c9c3d,6f543a4bc70440bc498c3cc7cd0708df15a84e41..e718487c97c3dd2b6a09ebcc4318218fc26ca1b1
--- 1/lib/Kconfig.debug
--- 2/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@@ -2015,7 -1999,18 +2015,17 @@@ config TEST_OBJAG
          Enable this option to test object aggregation manager on boot
          (or module load).
  
 -        If unsure, say N.
  
+ config TEST_STACKINIT
+       tristate "Test level of stack variable initialization"
+       help
+         Test if the kernel is zero-initializing stack variables and
+         padding. Coverage is controlled by compiler flags,
+         CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
+         or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
+ 
+         If unsure, say N.
+ 
  endif # RUNTIME_TESTING_MENU
  
  config MEMTEST

diff --cc lib/Makefile
index c7ae0b3e4535c72b43101a3cb5d9a92a86f56726,c81a66d4d00d6b6cc26d38a817b2d02a43a61f29..647517940b298ccb72e732499b226ba0d044fe63
--- 1/lib/Makefile
--- 2/lib/Makefile
+++ b/lib/Makefile
@@@ -77,9 -76,8 +77,10 @@@ obj-$(CONFIG_TEST_KMOD) += test_kmod.
  obj-$(CONFIG_TEST_DEBUG_VIRTUAL) += test_debug_virtual.o
  obj-$(CONFIG_TEST_MEMCAT_P) += test_memcat_p.o
  obj-$(CONFIG_TEST_OBJAGG) += test_objagg.o
+ obj-$(CONFIG_TEST_STACKINIT) += test_stackinit.o
  
 +obj-$(CONFIG_TEST_LIVEPATCH) += livepatch/
 +
  ifeq ($(CONFIG_DEBUG_KOBJECT),y)
  CFLAGS_kobject.o += -DDEBUG
  CFLAGS_kobject_uevent.o += -DDEBUG

diff --cc scripts/gcc-plugins/Kconfig
index d9fd9988ef271368034ea814148c4b2fb975c47a,d0cc92e48f6fc7b29e1e3218814612e702f960c8..74271dba4f94b5963c5f08a613d181269969868f
--- 1/scripts/gcc-plugins/Kconfig
--- 2/scripts/gcc-plugins/Kconfig
+++ b/scripts/gcc-plugins/Kconfig
@@@ -67,13 -67,22 +67,18 @@@ config GCC_PLUGIN_LATENT_ENTROP
           * https://pax.grsecurity.net/
  
  config GCC_PLUGIN_STRUCTLEAK
-       bool "Force initialization of variables containing userspace addresses"
+       bool "Zero initialize stack variables"
 -      # Currently STRUCTLEAK inserts initialization out of live scope of
 -      # variables from KASAN point of view. This leads to KASAN false
 -      # positive reports. Prohibit this combination for now.
 -      depends on !KASAN_EXTRA
        help
-         This plugin zero-initializes any structures containing a
-         __user attribute. This can prevent some classes of information
-         exposures.
- 
-         This plugin was ported from grsecurity/PaX. More information at:
+         While the kernel is built with warnings enabled for any missed
+         stack variable initializations, this warning is silenced for
+         anything passed by reference to another function, under the
+         occasionally misguided assumption that the function will do
+         the initialization. As this regularly leads to exploitable
+         flaws, this plugin is available to identify and zero-initialize
+         such variables, depending on the chosen level of coverage.
+ 
+         This plugin was originally ported from grsecurity/PaX. More
+         information at:
           * https://grsecurity.net/
           * https://pax.grsecurity.net/