Commit ebb6d35a authored Aug 02, 2019 by Arnd Bergmann Committed by Linus Torvalds Aug 03, 2019

kasan: remove clang version check for KASAN_STACK

asan-stack mode still uses dangerously large kernel stacks of tens of
kilobytes in some drivers, and it does not seem that anyone is working
on the clang bug.

Turn it off for all clang versions to prevent users from accidentally
enabling it once they update to clang-9, and to help automated build
testing with clang-9.

Link: https://bugs.llvm.org/show_bug.cgi?id=38809
Link: http://lkml.kernel.org/r/20190719200347.2596375-1-arnd@arndb.de


Fixes: 6baec880 ("kasan: turn off asan-stack for clang-8 and earlier")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 670105a2

lib/Kconfig.kasan

+5 −6

Original line number	Diff line number	Diff line
		@@ -106,7 +106,6 @@ endchoice

		config KASAN_STACK_ENABLE
		bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST
		default !(CLANG_VERSION < 90000)
		depends on KASAN
		help
		The LLVM stack address sanitizer has a know problem that
		@@ -115,11 +114,11 @@ config KASAN_STACK_ENABLE
		Disabling asan-stack makes it safe to run kernels build
		with clang-8 with KASAN enabled, though it loses some of
		the functionality.
		This feature is always disabled when compile-testing with clang-8
		or earlier to avoid cluttering the output in stack overflow
		warnings, but clang-8 users can still enable it for builds without
		CONFIG_COMPILE_TEST. On gcc and later clang versions it is
		assumed to always be safe to use and enabled by default.
		This feature is always disabled when compile-testing with clang
		to avoid cluttering the output in stack overflow warnings,
		but clang users can still enable it for builds without
		CONFIG_COMPILE_TEST. On gcc it is assumed to always be safe
		to use and enabled by default.

		config KASAN_STACK
		int

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