From 58ee788cb23738abd57d6327d0b5096df5a53d31 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Thu, 21 Dec 2023 21:04:49 +0100 Subject: kasan: respect CONFIG_KASAN_VMALLOC for kasan_flag_vmalloc Never enable the kasan_flag_vmalloc static branch unless CONFIG_KASAN_VMALLOC is enabled. This does not fix any observable bugs (vmalloc annotations for the HW_TAGS mode are no-op with CONFIG_KASAN_VMALLOC disabled) but rather just cleans up the code. Link: https://lkml.kernel.org/r/3e5c933c8f6b59bd587efb05c407964be951772c.1703188911.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Marco Elver Signed-off-by: Andrew Morton --- mm/kasan/hw_tags.c | 7 +++++++ mm/kasan/kasan.h | 1 + 2 files changed, 8 insertions(+) (limited to 'mm/kasan') diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 06141bbc1e51..80f11a3eccd5 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -57,7 +57,11 @@ enum kasan_mode kasan_mode __ro_after_init; EXPORT_SYMBOL_GPL(kasan_mode); /* Whether to enable vmalloc tagging. */ +#ifdef CONFIG_KASAN_VMALLOC DEFINE_STATIC_KEY_TRUE(kasan_flag_vmalloc); +#else +DEFINE_STATIC_KEY_FALSE(kasan_flag_vmalloc); +#endif #define PAGE_ALLOC_SAMPLE_DEFAULT 1 #define PAGE_ALLOC_SAMPLE_ORDER_DEFAULT 3 @@ -119,6 +123,9 @@ static int __init early_kasan_flag_vmalloc(char *arg) if (!arg) return -EINVAL; + if (!IS_ENABLED(CONFIG_KASAN_VMALLOC)) + return 0; + if (!strcmp(arg, "off")) kasan_arg_vmalloc = KASAN_ARG_VMALLOC_OFF; else if (!strcmp(arg, "on")) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 5fbcc1b805bc..dee105ba32dd 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -49,6 +49,7 @@ DECLARE_PER_CPU(long, kasan_page_alloc_skip); static inline bool kasan_vmalloc_enabled(void) { + /* Static branch is never enabled with CONFIG_KASAN_VMALLOC disabled. */ return static_branch_likely(&kasan_flag_vmalloc); } -- cgit v1.2.3