On Wed, 20 Oct 2021 at 08:13, Kuan-Ying Lee <Kuan-Ying.Lee@xxxxxxxxxxxx> wrote: > > There are multiple kasan modes. It makes sense that we add some messages > to know which kasan mode is when booting up. see [1]. > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=212195 [1] > Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@xxxxxxxxxxxx> > --- > change since v2: > - Rebase to linux-next > - HW-tags based mode need to consider asymm mode > - Thanks for Marco's suggestion > > arch/arm64/mm/kasan_init.c | 2 +- > mm/kasan/hw_tags.c | 4 +++- > mm/kasan/kasan.h | 10 ++++++++++ > mm/kasan/sw_tags.c | 2 +- > 4 files changed, 15 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c > index 5b996ca4d996..6f5a6fe8edd7 100644 > --- a/arch/arm64/mm/kasan_init.c > +++ b/arch/arm64/mm/kasan_init.c > @@ -309,7 +309,7 @@ void __init kasan_init(void) > kasan_init_depth(); > #if defined(CONFIG_KASAN_GENERIC) > /* CONFIG_KASAN_SW_TAGS also requires kasan_init_sw_tags(). */ > - pr_info("KernelAddressSanitizer initialized\n"); > + pr_info("KernelAddressSanitizer initialized (generic)\n"); > #endif > } > > diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c > index dc892119e88f..1d5c89c7cdfe 100644 > --- a/mm/kasan/hw_tags.c > +++ b/mm/kasan/hw_tags.c > @@ -177,7 +177,9 @@ void __init kasan_init_hw_tags(void) > break; > } > > - pr_info("KernelAddressSanitizer initialized\n"); > + pr_info("KernelAddressSanitizer initialized (hw-tags, mode=%s, stacktrace=%s)\n", > + kasan_mode_info(), > + kasan_stack_collection_enabled() ? "on" : "off"); > } > > void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags) > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index aebd8df86a1f..387ed7b6de37 100644 > --- a/mm/kasan/kasan.h > +++ b/mm/kasan/kasan.h > @@ -36,6 +36,16 @@ static inline bool kasan_sync_fault_possible(void) > { > return kasan_mode == KASAN_MODE_SYNC || kasan_mode == KASAN_MODE_ASYMM; > } > + > +static inline const char *kasan_mode_info(void) > +{ > + if (kasan_mode == KASAN_MODE_ASYNC) > + return "async"; > + else if (kasan_mode == KASAN_MODE_ASYMM) > + return "asymm"; > + else > + return "sync"; > +} This creates an inconsistency, because for kasan_stack_collection_enabled(), kasan_async_fault_possible(), and kasan_sync_fault_possible() there are !KASAN_HW_TAGS stubs. A stub for kasan_mode_info() if !KASAN_HW_TAGS appears useless though, and I wouldn't know what its return value should be. Do you expect this helper to be used outside hw_tags.c? If not, perhaps just move it into hw_tags.c. Thanks, -- Marco
