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Date:   Mon, 29 Jun 2020 12:41:56 +0200
Message-Id: <20200629104157.3242503-1-elver@google.com>
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Subject: [PATCH 1/2] kasan: Improve and simplify Kconfig.kasan
From:   Marco Elver <elver@google.com>
To:     elver@google.com, akpm@linux-foundation.org
Cc:     dvyukov@google.com, glider@google.com, andreyknvl@google.com,
        linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
        aryabinin@virtuozzo.com, ndesaulniers@google.com,
        walter-zh.wu@mediatek.com, arnd@arndb.de, dja@axtens.net,
        linux-doc@vger.kernel.org, clang-built-linux@googlegroups.com
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Sender: linux-kernel-owner@vger.kernel.org
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Turn 'KASAN' into a menuconfig, to avoid cluttering its parent menu with
the suboptions if enabled. Use 'if KASAN ... endif' instead of having
to 'depend on KASAN' for each entry.

Signed-off-by: Marco Elver <elver@google.com>
---
 lib/Kconfig.kasan | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index 34b84bcbd3d9..89053defc0d9 100644
--- a/lib/Kconfig.kasan
+++ b/lib/Kconfig.kasan
@@ -18,7 +18,7 @@ config CC_HAS_KASAN_SW_TAGS
 config CC_HAS_WORKING_NOSANITIZE_ADDRESS
 	def_bool !CC_IS_GCC || GCC_VERSION >= 80300
 
-config KASAN
+menuconfig KASAN
 	bool "KASAN: runtime memory debugger"
 	depends on (HAVE_ARCH_KASAN && CC_HAS_KASAN_GENERIC) || \
 		   (HAVE_ARCH_KASAN_SW_TAGS && CC_HAS_KASAN_SW_TAGS)
@@ -29,9 +29,10 @@ config KASAN
 	  designed to find out-of-bounds accesses and use-after-free bugs.
 	  See Documentation/dev-tools/kasan.rst for details.
 
+if KASAN
+
 choice
 	prompt "KASAN mode"
-	depends on KASAN
 	default KASAN_GENERIC
 	help
 	  KASAN has two modes: generic KASAN (similar to userspace ASan,
@@ -88,7 +89,6 @@ endchoice
 
 choice
 	prompt "Instrumentation type"
-	depends on KASAN
 	default KASAN_OUTLINE
 
 config KASAN_OUTLINE
@@ -113,7 +113,6 @@ endchoice
 
 config KASAN_STACK_ENABLE
 	bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST
-	depends on KASAN
 	help
 	  The LLVM stack address sanitizer has a know problem that
 	  causes excessive stack usage in a lot of functions, see
@@ -134,7 +133,7 @@ config KASAN_STACK
 
 config KASAN_S390_4_LEVEL_PAGING
 	bool "KASan: use 4-level paging"
-	depends on KASAN && S390
+	depends on S390
 	help
 	  Compiling the kernel with KASan disables automatic 3-level vs
 	  4-level paging selection. 3-level paging is used by default (up
@@ -151,7 +150,7 @@ config KASAN_SW_TAGS_IDENTIFY
 
 config KASAN_VMALLOC
 	bool "Back mappings in vmalloc space with real shadow memory"
-	depends on KASAN && HAVE_ARCH_KASAN_VMALLOC
+	depends on HAVE_ARCH_KASAN_VMALLOC
 	help
 	  By default, the shadow region for vmalloc space is the read-only
 	  zero page. This means that KASAN cannot detect errors involving
@@ -164,8 +163,10 @@ config KASAN_VMALLOC
 
 config TEST_KASAN
 	tristate "Module for testing KASAN for bug detection"
-	depends on m && KASAN
+	depends on m
 	help
 	  This is a test module doing various nasty things like
 	  out of bounds accesses, use after free. It is useful for testing
 	  kernel debugging features like KASAN.
+
+endif # KASAN
-- 
2.27.0.212.ge8ba1cc988-goog