[PATCH] kasan: add missing Kconfig dependencies

[Arnd Bergmann <arnd@arndb.de>]

Building with CONFIG_KASAN=y when neither KASAN_GENERIC nor KASAN_SW_TAGS
can be selected leads to a build error:

arch/arm64/mm/kasan_init.c: In function 'kasan_pte_populate':
arch/arm64/mm/kasan_init.c:106:28: error: 'KASAN_SHADOW_INIT' undeclared (first use in this function); did you mean 'KASAN_SHADOW_END'?

We should really only allow enabling KASAN when all its dependencies
are met as it was before the introduction of CONFIG_KASAN_SW_TAGS.

Fixes: b8440cc16515 ("kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 lib/Kconfig.kasan | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index b5d0cbfce4a1..83286bca2f70 100644
--- a/lib/Kconfig.kasan
+++ b/lib/Kconfig.kasan
@@ -15,6 +15,8 @@ if HAVE_ARCH_KASAN
 
 config KASAN
 	bool "KASAN: runtime memory debugger"
+	depends on CC_HAS_KASAN_GENERIC || CC_HAS_KASAN_SW_TAGS
+	depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB)
 	help
 	  Enables KASAN (KernelAddressSANitizer) - runtime memory debugger,
 	  designed to find out-of-bounds accesses and use-after-free bugs.
-- 
2.20.0