Messages in this thread | | | From | Andrey Konovalov <> | Date | Fri, 8 Apr 2022 14:26:07 +0200 | Subject | Re: [PATCH] kasan: Fix hw tags enablement when KUNIT tests are disabled |
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On Fri, Apr 8, 2022 at 12:04 PM Vincenzo Frascino <vincenzo.frascino@arm.com> wrote: > > Kasan enables hw tags via kasan_enable_tagging() which based on the mode > passed via kernel command line selects the correct hw backend. > kasan_enable_tagging() is meant to be invoked indirectly via the cpu features > framework of the architectures that support these backends. > Currently the invocation of this function is guarded by CONFIG_KASAN_KUNIT_TEST > which allows the enablement of the correct backend only when KUNIT tests are > enabled in the kernel.
> ... and prevents to enable MTE on arm64 when KUNIT tests for kasan hw_tags are > disabled.
Oh, indeed. Thanks for finding this!
> This inconsistency was introduced in commit: > > f05842cfb9ae2 ("kasan, arm64: allow using KUnit tests with HW_TAGS mode")
No, that commit is fine. The issue was introduced recently in ed6d74446cbf ("kasan: test: support async (again) and asymm modes for HW_TAGS"), where I changed kasan_init_hw_tags_cpu() to call kasan_enable_tagging() instead of hw_enable_tagging_*().
> Fix the issue making sure that the CONFIG_KASAN_KUNIT_TEST guard does not > prevent the correct invocation of kasan_enable_tagging(). > > Fixes: f05842cfb9ae2 ("kasan, arm64: allow using KUnit tests with HW_TAGS mode") > Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> > Cc: Alexander Potapenko <glider@google.com> > Cc: Andrey Konovalov <andreyknvl@gmail.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> > --- > mm/kasan/hw_tags.c | 4 ++-- > mm/kasan/kasan.h | 10 ++++++---- > 2 files changed, 8 insertions(+), 6 deletions(-) > > diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c > index 07a76c46daa5..e2677501c36e 100644 > --- a/mm/kasan/hw_tags.c > +++ b/mm/kasan/hw_tags.c > @@ -336,8 +336,6 @@ void __kasan_poison_vmalloc(const void *start, unsigned long size) > > #endif > > -#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) > - > void kasan_enable_tagging(void) > { > if (kasan_arg_mode == KASAN_ARG_MODE_ASYNC) > @@ -349,6 +347,8 @@ void kasan_enable_tagging(void) > } > EXPORT_SYMBOL_GPL(kasan_enable_tagging);
Please keep this EXPORT_SYMBOL_GPL under CONFIG_KASAN_KUNIT_TEST.
> > +#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) > + > void kasan_force_async_fault(void) > { > hw_force_async_tag_fault(); > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index d79b83d673b1..b01b4bbe0409 100644 > --- a/mm/kasan/kasan.h > +++ b/mm/kasan/kasan.h > @@ -355,25 +355,27 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) > #define hw_set_mem_tag_range(addr, size, tag, init) \ > arch_set_mem_tag_range((addr), (size), (tag), (init)) > > +void kasan_enable_tagging(void); > + > #else /* CONFIG_KASAN_HW_TAGS */ > > #define hw_enable_tagging_sync() > #define hw_enable_tagging_async() > #define hw_enable_tagging_asymm() > > +static inline void kasan_enable_tagging(void) { } > + > #endif /* CONFIG_KASAN_HW_TAGS */ > > #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) > > -void kasan_enable_tagging(void); > void kasan_force_async_fault(void); > > -#else /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */ > +#else /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */ > > -static inline void kasan_enable_tagging(void) { } > static inline void kasan_force_async_fault(void) { } > > -#endif /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */ > +#endif /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */ > > #ifdef CONFIG_KASAN_SW_TAGS > u8 kasan_random_tag(void); > -- > 2.35.1 >
Thank you, Vincenzo!
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