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 <[email protected]>
---
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";
+}
#else
static inline bool kasan_stack_collection_enabled(void)
diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c
index bd3f540feb47..77f13f391b57 100644
--- a/mm/kasan/sw_tags.c
+++ b/mm/kasan/sw_tags.c
@@ -42,7 +42,7 @@ void __init kasan_init_sw_tags(void)
for_each_possible_cpu(cpu)
per_cpu(prng_state, cpu) = (u32)get_cycles();
- pr_info("KernelAddressSanitizer initialized\n");
+ pr_info("KernelAddressSanitizer initialized (sw-tags)\n");
}
/*
--
2.18.0
On Wed, 20 Oct 2021 at 08:13, Kuan-Ying Lee <[email protected]> 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 <[email protected]>
> ---
> 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
On Wed, 2021-10-20 at 15:23 +0800, Marco Elver wrote:
> On Wed, 20 Oct 2021 at 08:13, Kuan-Ying Lee <
> [email protected]> 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://urldefense.com/v3/__https://bugzilla.kernel.org/show_bug.cgi?id=212195__;!!CTRNKA9wMg0ARbw!yylpqk8mnd0N8w6pn4Mn4sIeu-GGlKXcA4I4yXlmstFsuqmpkhaM2V_uu2c6oPMFpZRqoQ$
> > $ [1]
> > Signed-off-by: Kuan-Ying Lee <[email protected]>
> > ---
> > 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.
The helper will be used only in hw_tags.c.
I will move it into hw_tags.c in v3.
Thanks.
>
> Thanks,
> -- Marco