* [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-24 11:26 ` yee.lee
0 siblings, 0 replies; 28+ messages in thread
From: yee.lee @ 2021-06-24 11:26 UTC (permalink / raw)
To: andreyknvl
Cc: wsd_upstream, Yee Lee, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
From: Yee Lee <yee.lee@mediatek.com>
Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
the redzone of object with unaligned size.
An additional memzero_explicit() path is added to replacing init by
hwtag instruction for those unaligned size at SLUB debug mode.
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
---
mm/kasan/kasan.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 8f450bc28045..d1054f35838f 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
return;
+#if IS_ENABLED(CONFIG_SLUB_DEBUG)
+ if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
+ init = false;
+ memzero_explicit((void *)addr, size);
+ }
+#endif
size = round_up(size, KASAN_GRANULE_SIZE);
hw_set_mem_tag_range((void *)addr, size, tag, init);
--
2.18.0
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 28+ messages in thread* [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-24 11:26 ` yee.lee
0 siblings, 0 replies; 28+ messages in thread
From: yee.lee @ 2021-06-24 11:26 UTC (permalink / raw)
To: andreyknvl
Cc: wsd_upstream, Yee Lee, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
From: Yee Lee <yee.lee@mediatek.com>
Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
the redzone of object with unaligned size.
An additional memzero_explicit() path is added to replacing init by
hwtag instruction for those unaligned size at SLUB debug mode.
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
---
mm/kasan/kasan.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 8f450bc28045..d1054f35838f 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
return;
+#if IS_ENABLED(CONFIG_SLUB_DEBUG)
+ if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
+ init = false;
+ memzero_explicit((void *)addr, size);
+ }
+#endif
size = round_up(size, KASAN_GRANULE_SIZE);
hw_set_mem_tag_range((void *)addr, size, tag, init);
--
2.18.0
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
^ permalink raw reply related [flat|nested] 28+ messages in thread* [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-24 11:26 ` yee.lee
0 siblings, 0 replies; 28+ messages in thread
From: yee.lee @ 2021-06-24 11:26 UTC (permalink / raw)
To: andreyknvl
Cc: wsd_upstream, Yee Lee, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
From: Yee Lee <yee.lee@mediatek.com>
Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
the redzone of object with unaligned size.
An additional memzero_explicit() path is added to replacing init by
hwtag instruction for those unaligned size at SLUB debug mode.
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
---
mm/kasan/kasan.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 8f450bc28045..d1054f35838f 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
return;
+#if IS_ENABLED(CONFIG_SLUB_DEBUG)
+ if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
+ init = false;
+ memzero_explicit((void *)addr, size);
+ }
+#endif
size = round_up(size, KASAN_GRANULE_SIZE);
hw_set_mem_tag_range((void *)addr, size, tag, init);
--
2.18.0
^ permalink raw reply related [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
2021-06-24 11:26 ` yee.lee
(?)
(?)
@ 2021-06-25 14:03 ` Andrey Konovalov
-1 siblings, 0 replies; 28+ messages in thread
From: Andrey Konovalov @ 2021-06-25 14:03 UTC (permalink / raw)
To: yee.lee
Cc: wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Thu, Jun 24, 2021 at 2:26 PM <yee.lee@mediatek.com> wrote:
>
> From: Yee Lee <yee.lee@mediatek.com>
>
> Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
> the redzone of object with unaligned size.
>
> An additional memzero_explicit() path is added to replacing init by
> hwtag instruction for those unaligned size at SLUB debug mode.
>
> Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> ---
> mm/kasan/kasan.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 8f450bc28045..d1054f35838f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
>
> if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> return;
> +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
Is this an issue only with SLUB? SLAB also uses redzones.
> + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
This needs a comment along the lines of:
/* Explicitly initialize the memory with the precise object size to
avoid overwriting the SLAB redzone. This disables initialization in
the arch code and may thus lead to performance penalty. The penalty is
accepted since SLAB redzones aren't enabled in production builds. */
> + init = false;
> + memzero_explicit((void *)addr, size);
> + }
> +#endif
> size = round_up(size, KASAN_GRANULE_SIZE);
>
> hw_set_mem_tag_range((void *)addr, size, tag, init);
> --
> 2.18.0
>
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-25 14:03 ` Andrey Konovalov
0 siblings, 0 replies; 28+ messages in thread
From: Andrey Konovalov @ 2021-06-25 14:03 UTC (permalink / raw)
To: yee.lee
Cc: wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Thu, Jun 24, 2021 at 2:26 PM <yee.lee@mediatek.com> wrote:
>
> From: Yee Lee <yee.lee@mediatek.com>
>
> Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
> the redzone of object with unaligned size.
>
> An additional memzero_explicit() path is added to replacing init by
> hwtag instruction for those unaligned size at SLUB debug mode.
>
> Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> ---
> mm/kasan/kasan.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 8f450bc28045..d1054f35838f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
>
> if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> return;
> +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
Is this an issue only with SLUB? SLAB also uses redzones.
> + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
This needs a comment along the lines of:
/* Explicitly initialize the memory with the precise object size to
avoid overwriting the SLAB redzone. This disables initialization in
the arch code and may thus lead to performance penalty. The penalty is
accepted since SLAB redzones aren't enabled in production builds. */
> + init = false;
> + memzero_explicit((void *)addr, size);
> + }
> +#endif
> size = round_up(size, KASAN_GRANULE_SIZE);
>
> hw_set_mem_tag_range((void *)addr, size, tag, init);
> --
> 2.18.0
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-25 14:03 ` Andrey Konovalov
0 siblings, 0 replies; 28+ messages in thread
From: Andrey Konovalov @ 2021-06-25 14:03 UTC (permalink / raw)
To: yee.lee
Cc: wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Thu, Jun 24, 2021 at 2:26 PM <yee.lee@mediatek.com> wrote:
>
> From: Yee Lee <yee.lee@mediatek.com>
>
> Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
> the redzone of object with unaligned size.
>
> An additional memzero_explicit() path is added to replacing init by
> hwtag instruction for those unaligned size at SLUB debug mode.
>
> Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> ---
> mm/kasan/kasan.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 8f450bc28045..d1054f35838f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
>
> if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> return;
> +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
Is this an issue only with SLUB? SLAB also uses redzones.
> + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
This needs a comment along the lines of:
/* Explicitly initialize the memory with the precise object size to
avoid overwriting the SLAB redzone. This disables initialization in
the arch code and may thus lead to performance penalty. The penalty is
accepted since SLAB redzones aren't enabled in production builds. */
> + init = false;
> + memzero_explicit((void *)addr, size);
> + }
> +#endif
> size = round_up(size, KASAN_GRANULE_SIZE);
>
> hw_set_mem_tag_range((void *)addr, size, tag, init);
> --
> 2.18.0
>
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-25 14:03 ` Andrey Konovalov
0 siblings, 0 replies; 28+ messages in thread
From: Andrey Konovalov @ 2021-06-25 14:03 UTC (permalink / raw)
To: yee.lee
Cc: wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Thu, Jun 24, 2021 at 2:26 PM <yee.lee@mediatek.com> wrote:
>
> From: Yee Lee <yee.lee@mediatek.com>
>
> Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
> the redzone of object with unaligned size.
>
> An additional memzero_explicit() path is added to replacing init by
> hwtag instruction for those unaligned size at SLUB debug mode.
>
> Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> ---
> mm/kasan/kasan.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 8f450bc28045..d1054f35838f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
>
> if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> return;
> +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
Is this an issue only with SLUB? SLAB also uses redzones.
> + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
This needs a comment along the lines of:
/* Explicitly initialize the memory with the precise object size to
avoid overwriting the SLAB redzone. This disables initialization in
the arch code and may thus lead to performance penalty. The penalty is
accepted since SLAB redzones aren't enabled in production builds. */
> + init = false;
> + memzero_explicit((void *)addr, size);
> + }
> +#endif
> size = round_up(size, KASAN_GRANULE_SIZE);
>
> hw_set_mem_tag_range((void *)addr, size, tag, init);
> --
> 2.18.0
>
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
2021-06-25 14:03 ` Andrey Konovalov
(?)
(?)
@ 2021-06-28 6:19 ` Yee Lee
-1 siblings, 0 replies; 28+ messages in thread
From: Yee Lee @ 2021-06-28 6:19 UTC (permalink / raw)
To: Andrey Konovalov
Cc: wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Fri, 2021-06-25 at 17:03 +0300, Andrey Konovalov wrote:
> On Thu, Jun 24, 2021 at 2:26 PM <yee.lee@mediatek.com> wrote:
> >
> > From: Yee Lee <yee.lee@mediatek.com>
> >
> > Issue: when SLUB debug is on, hwtag kasan_unpoison() would
> > overwrite
> > the redzone of object with unaligned size.
> >
> > An additional memzero_explicit() path is added to replacing init by
> > hwtag instruction for those unaligned size at SLUB debug mode.
> >
> > Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> > ---
> > mm/kasan/kasan.h | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> > index 8f450bc28045..d1054f35838f 100644
> > --- a/mm/kasan/kasan.h
> > +++ b/mm/kasan/kasan.h
> > @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void
> > *addr, size_t size, bool init)
> >
> > if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> > return;
> > +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
>
> Is this an issue only with SLUB? SLAB also uses redzones.
As I known, hw-tag kasan only works with SLUB.
>
> > + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
>
> This needs a comment along the lines of:
>
> /* Explicitly initialize the memory with the precise object size to
> avoid overwriting the SLAB redzone. This disables initialization in
> the arch code and may thus lead to performance penalty. The penalty
> is
> accepted since SLAB redzones aren't enabled in production builds. */
Sure, will work on this.
>
> > + init = false;
> > + memzero_explicit((void *)addr, size);
> > + }
> > +#endif
> > size = round_up(size, KASAN_GRANULE_SIZE);
> >
> > hw_set_mem_tag_range((void *)addr, size, tag, init);
> > --
> > 2.18.0
> >
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-28 6:19 ` Yee Lee
0 siblings, 0 replies; 28+ messages in thread
From: Yee Lee @ 2021-06-28 6:19 UTC (permalink / raw)
To: Andrey Konovalov
Cc: wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Fri, 2021-06-25 at 17:03 +0300, Andrey Konovalov wrote:
> On Thu, Jun 24, 2021 at 2:26 PM <yee.lee@mediatek.com> wrote:
> >
> > From: Yee Lee <yee.lee@mediatek.com>
> >
> > Issue: when SLUB debug is on, hwtag kasan_unpoison() would
> > overwrite
> > the redzone of object with unaligned size.
> >
> > An additional memzero_explicit() path is added to replacing init by
> > hwtag instruction for those unaligned size at SLUB debug mode.
> >
> > Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> > ---
> > mm/kasan/kasan.h | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> > index 8f450bc28045..d1054f35838f 100644
> > --- a/mm/kasan/kasan.h
> > +++ b/mm/kasan/kasan.h
> > @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void
> > *addr, size_t size, bool init)
> >
> > if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> > return;
> > +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
>
> Is this an issue only with SLUB? SLAB also uses redzones.
As I known, hw-tag kasan only works with SLUB.
>
> > + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
>
> This needs a comment along the lines of:
>
> /* Explicitly initialize the memory with the precise object size to
> avoid overwriting the SLAB redzone. This disables initialization in
> the arch code and may thus lead to performance penalty. The penalty
> is
> accepted since SLAB redzones aren't enabled in production builds. */
Sure, will work on this.
>
> > + init = false;
> > + memzero_explicit((void *)addr, size);
> > + }
> > +#endif
> > size = round_up(size, KASAN_GRANULE_SIZE);
> >
> > hw_set_mem_tag_range((void *)addr, size, tag, init);
> > --
> > 2.18.0
> >
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-28 6:19 ` Yee Lee
0 siblings, 0 replies; 28+ messages in thread
From: Yee Lee @ 2021-06-28 6:19 UTC (permalink / raw)
To: Andrey Konovalov
Cc: wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Fri, 2021-06-25 at 17:03 +0300, Andrey Konovalov wrote:
> On Thu, Jun 24, 2021 at 2:26 PM <yee.lee@mediatek.com> wrote:
> >
> > From: Yee Lee <yee.lee@mediatek.com>
> >
> > Issue: when SLUB debug is on, hwtag kasan_unpoison() would
> > overwrite
> > the redzone of object with unaligned size.
> >
> > An additional memzero_explicit() path is added to replacing init by
> > hwtag instruction for those unaligned size at SLUB debug mode.
> >
> > Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> > ---
> > mm/kasan/kasan.h | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> > index 8f450bc28045..d1054f35838f 100644
> > --- a/mm/kasan/kasan.h
> > +++ b/mm/kasan/kasan.h
> > @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void
> > *addr, size_t size, bool init)
> >
> > if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> > return;
> > +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
>
> Is this an issue only with SLUB? SLAB also uses redzones.
As I known, hw-tag kasan only works with SLUB.
>
> > + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
>
> This needs a comment along the lines of:
>
> /* Explicitly initialize the memory with the precise object size to
> avoid overwriting the SLAB redzone. This disables initialization in
> the arch code and may thus lead to performance penalty. The penalty
> is
> accepted since SLAB redzones aren't enabled in production builds. */
Sure, will work on this.
>
> > + init = false;
> > + memzero_explicit((void *)addr, size);
> > + }
> > +#endif
> > size = round_up(size, KASAN_GRANULE_SIZE);
> >
> > hw_set_mem_tag_range((void *)addr, size, tag, init);
> > --
> > 2.18.0
> >
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-28 6:19 ` Yee Lee
0 siblings, 0 replies; 28+ messages in thread
From: Yee Lee @ 2021-06-28 6:19 UTC (permalink / raw)
To: Andrey Konovalov
Cc: wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Fri, 2021-06-25 at 17:03 +0300, Andrey Konovalov wrote:
> On Thu, Jun 24, 2021 at 2:26 PM <yee.lee@mediatek.com> wrote:
> >
> > From: Yee Lee <yee.lee@mediatek.com>
> >
> > Issue: when SLUB debug is on, hwtag kasan_unpoison() would
> > overwrite
> > the redzone of object with unaligned size.
> >
> > An additional memzero_explicit() path is added to replacing init by
> > hwtag instruction for those unaligned size at SLUB debug mode.
> >
> > Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> > ---
> > mm/kasan/kasan.h | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> > index 8f450bc28045..d1054f35838f 100644
> > --- a/mm/kasan/kasan.h
> > +++ b/mm/kasan/kasan.h
> > @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void
> > *addr, size_t size, bool init)
> >
> > if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> > return;
> > +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
>
> Is this an issue only with SLUB? SLAB also uses redzones.
As I known, hw-tag kasan only works with SLUB.
>
> > + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
>
> This needs a comment along the lines of:
>
> /* Explicitly initialize the memory with the precise object size to
> avoid overwriting the SLAB redzone. This disables initialization in
> the arch code and may thus lead to performance penalty. The penalty
> is
> accepted since SLAB redzones aren't enabled in production builds. */
Sure, will work on this.
>
> > + init = false;
> > + memzero_explicit((void *)addr, size);
> > + }
> > +#endif
> > size = round_up(size, KASAN_GRANULE_SIZE);
> >
> > hw_set_mem_tag_range((void *)addr, size, tag, init);
> > --
> > 2.18.0
> >
^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
2021-06-24 11:26 ` yee.lee
(?)
(?)
@ 2021-06-28 18:41 ` Marco Elver
-1 siblings, 0 replies; 28+ messages in thread
From: Marco Elver @ 2021-06-28 18:41 UTC (permalink / raw)
To: yee.lee
Cc: andreyknvl, wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Thu, 24 Jun 2021 at 13:27, <yee.lee@mediatek.com> wrote:
>
> From: Yee Lee <yee.lee@mediatek.com>
>
> Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
> the redzone of object with unaligned size.
>
> An additional memzero_explicit() path is added to replacing init by
> hwtag instruction for those unaligned size at SLUB debug mode.
>
> Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> ---
> mm/kasan/kasan.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 8f450bc28045..d1054f35838f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
>
> if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> return;
> +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
Avoid the #if. I think none of the stuff referenced here is only
available if CONFIG_SLUB_DEBUG. In that case, please just write:
if (IS_ENABLED(CONFIG_SLUB_DEBUG) && init && .........) {
The compiler will correctly optimize out the branch if the config
option is not enabled. But the benefit is we compile-test this code
with all configs.
> + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
> + init = false;
> + memzero_explicit((void *)addr, size);
> + }
> +#endif
Thanks,
-- Marco
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-28 18:41 ` Marco Elver
0 siblings, 0 replies; 28+ messages in thread
From: Marco Elver @ 2021-06-28 18:41 UTC (permalink / raw)
To: yee.lee
Cc: andreyknvl, wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Thu, 24 Jun 2021 at 13:27, <yee.lee@mediatek.com> wrote:
>
> From: Yee Lee <yee.lee@mediatek.com>
>
> Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
> the redzone of object with unaligned size.
>
> An additional memzero_explicit() path is added to replacing init by
> hwtag instruction for those unaligned size at SLUB debug mode.
>
> Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> ---
> mm/kasan/kasan.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 8f450bc28045..d1054f35838f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
>
> if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> return;
> +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
Avoid the #if. I think none of the stuff referenced here is only
available if CONFIG_SLUB_DEBUG. In that case, please just write:
if (IS_ENABLED(CONFIG_SLUB_DEBUG) && init && .........) {
The compiler will correctly optimize out the branch if the config
option is not enabled. But the benefit is we compile-test this code
with all configs.
> + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
> + init = false;
> + memzero_explicit((void *)addr, size);
> + }
> +#endif
Thanks,
-- Marco
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-28 18:41 ` Marco Elver
0 siblings, 0 replies; 28+ messages in thread
From: Marco Elver @ 2021-06-28 18:41 UTC (permalink / raw)
To: yee.lee
Cc: andreyknvl, wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Thu, 24 Jun 2021 at 13:27, <yee.lee@mediatek.com> wrote:
>
> From: Yee Lee <yee.lee@mediatek.com>
>
> Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
> the redzone of object with unaligned size.
>
> An additional memzero_explicit() path is added to replacing init by
> hwtag instruction for those unaligned size at SLUB debug mode.
>
> Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> ---
> mm/kasan/kasan.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 8f450bc28045..d1054f35838f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
>
> if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> return;
> +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
Avoid the #if. I think none of the stuff referenced here is only
available if CONFIG_SLUB_DEBUG. In that case, please just write:
if (IS_ENABLED(CONFIG_SLUB_DEBUG) && init && .........) {
The compiler will correctly optimize out the branch if the config
option is not enabled. But the benefit is we compile-test this code
with all configs.
> + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
> + init = false;
> + memzero_explicit((void *)addr, size);
> + }
> +#endif
Thanks,
-- Marco
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek
^ permalink raw reply [flat|nested] 28+ messages in thread* Re: [PATCH v2 1/1] kasan: Add memzero init for unaligned size under SLUB debug
@ 2021-06-28 18:41 ` Marco Elver
0 siblings, 0 replies; 28+ messages in thread
From: Marco Elver @ 2021-06-28 18:41 UTC (permalink / raw)
To: yee.lee
Cc: andreyknvl, wsd_upstream, Andrey Ryabinin, Alexander Potapenko,
Dmitry Vyukov, Andrew Morton, Matthias Brugger, open list:KASAN,
open list:MEMORY MANAGEMENT, open list,
moderated list:ARM/Mediatek SoC support,
moderated list:ARM/Mediatek SoC support
On Thu, 24 Jun 2021 at 13:27, <yee.lee@mediatek.com> wrote:
>
> From: Yee Lee <yee.lee@mediatek.com>
>
> Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite
> the redzone of object with unaligned size.
>
> An additional memzero_explicit() path is added to replacing init by
> hwtag instruction for those unaligned size at SLUB debug mode.
>
> Signed-off-by: Yee Lee <yee.lee@mediatek.com>
> ---
> mm/kasan/kasan.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 8f450bc28045..d1054f35838f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -387,6 +387,12 @@ static inline void kasan_unpoison(const void *addr, size_t size, bool init)
>
> if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
> return;
> +#if IS_ENABLED(CONFIG_SLUB_DEBUG)
Avoid the #if. I think none of the stuff referenced here is only
available if CONFIG_SLUB_DEBUG. In that case, please just write:
if (IS_ENABLED(CONFIG_SLUB_DEBUG) && init && .........) {
The compiler will correctly optimize out the branch if the config
option is not enabled. But the benefit is we compile-test this code
with all configs.
> + if (init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
> + init = false;
> + memzero_explicit((void *)addr, size);
> + }
> +#endif
Thanks,
-- Marco
^ permalink raw reply [flat|nested] 28+ messages in thread