lib: introduce test_meminit module

Add tests for heap and pagealloc initialization.  These can be used to
check init_on_alloc and init_on_free implementations as well as other
approaches to initialization.

Expected test output in the case the kernel provides heap initialization
(e.g.  when running with either init_on_alloc=1 or init_on_free=1):

  test_meminit: all 10 tests in test_pages passed
  test_meminit: all 40 tests in test_kvmalloc passed
  test_meminit: all 60 tests in test_kmemcache passed
  test_meminit: all 10 tests in test_rcu_persistent passed
  test_meminit: all 120 tests passed!

Link: http://lkml.kernel.org/r/20190529123812.43089-4-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Sandeep Patil <sspatil@android.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 4ac4ca21a30a..c6ee805202bd 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2076,6 +2076,14 @@ config TEST_STACKINIT
 
           If unsure, say N.
 
+config TEST_MEMINIT
+        tristate "Test heap/page initialization"
+        help
+          Test if the kernel is zero-initializing heap and page allocations.
+          This can be useful to test init_on_alloc and init_on_free features.
+
+          If unsure, say N.
+
 endif # RUNTIME_TESTING_MENU
 
 config MEMTEST