kasan: split kasan_*enabled() functions into a separate header

In an upcoming commit we are going to need to call
kasan_hw_tags_enabled() from arch/arm64/include/asm/mte.h. This
would create a circular dependency between headers if KASAN_GENERIC
or KASAN_SW_TAGS is enabled: linux/kasan.h -> linux/pgtable.h ->
asm/pgtable.h -> asm/mte.h -> linux/kasan.h. Break the cycle
by introducing a new header linux/kasan-enabled.h with the
kasan_*enabled() functions that can be included from asm/mte.h.

Link: https://linux-review.googlesource.com/id/I5b0d96c6ed0026fc790899e14d42b2fac6ab568e
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20220219012945.894950-1-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Peter Collingbourne 2022-02-18 17:29:44 -08:00 committed by Will Deacon
parent dfd42facf1
commit f9b5e46f40
2 changed files with 34 additions and 22 deletions

View File

@ -0,0 +1,33 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KASAN_ENABLED_H
#define _LINUX_KASAN_ENABLED_H
#ifdef CONFIG_KASAN_HW_TAGS
DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled);
static __always_inline bool kasan_enabled(void)
{
return static_branch_likely(&kasan_flag_enabled);
}
static inline bool kasan_hw_tags_enabled(void)
{
return kasan_enabled();
}
#else /* CONFIG_KASAN_HW_TAGS */
static inline bool kasan_enabled(void)
{
return IS_ENABLED(CONFIG_KASAN);
}
static inline bool kasan_hw_tags_enabled(void)
{
return false;
}
#endif /* CONFIG_KASAN_HW_TAGS */
#endif /* LINUX_KASAN_ENABLED_H */

View File

@ -3,6 +3,7 @@
#define _LINUX_KASAN_H
#include <linux/bug.h>
#include <linux/kasan-enabled.h>
#include <linux/kernel.h>
#include <linux/static_key.h>
#include <linux/types.h>
@ -83,33 +84,11 @@ static inline void kasan_disable_current(void) {}
#ifdef CONFIG_KASAN_HW_TAGS
DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled);
static __always_inline bool kasan_enabled(void)
{
return static_branch_likely(&kasan_flag_enabled);
}
static inline bool kasan_hw_tags_enabled(void)
{
return kasan_enabled();
}
void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags);
void kasan_free_pages(struct page *page, unsigned int order);
#else /* CONFIG_KASAN_HW_TAGS */
static inline bool kasan_enabled(void)
{
return IS_ENABLED(CONFIG_KASAN);
}
static inline bool kasan_hw_tags_enabled(void)
{
return false;
}
static __always_inline void kasan_alloc_pages(struct page *page,
unsigned int order, gfp_t flags)
{