All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dmitry Vyukov <dvyukov@google.com>
To: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Christoph Lameter <cl@linux.com>,
	David Rientjes <rientjes@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Pekka Enberg <penberg@kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Andrey Konovalov <andreyknvl@google.com>,
	Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Eric Dumazet <edumazet@google.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Ingo Molnar <mingo@redhat.com>, Jann Horn <jannh@google.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Kees Cook <keescook@chromium.org>,
	Peter Zijlstra <peterz@infradead.org>, Qian Cai <cai@lca.pw>,
	Thomas Gleixner <tglx@linutronix.de>,
	Will Deacon <will@kernel.org>,
	"the arch/x86 maintainers" <x86@kernel.org>,
	"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	kasan-dev <kasan-dev@googlegroups.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux-MM <linux-mm@kvack.org>
Subject: Re: [PATCH RFC 06/10] kfence, kasan: make KFENCE compatible with KASAN
Date: Fri, 11 Sep 2020 09:04:54 +0200	[thread overview]
Message-ID: <CACT4Y+b=Ph-fD_K5F_TNMp_dTNjD7GXGT=OXogrKc_HwH+HHwQ@mail.gmail.com> (raw)
In-Reply-To: <20200907134055.2878499-7-elver@google.com>

On Mon, Sep 7, 2020 at 3:41 PM Marco Elver <elver@google.com> wrote:
>
> From: Alexander Potapenko <glider@google.com>
>
> We make KFENCE compatible with KASAN for testing KFENCE itself. In
> particular, KASAN helps to catch any potential corruptions to KFENCE
> state, or other corruptions that may be a result of freepointer
> corruptions in the main allocators.
>
> To indicate that the combination of the two is generally discouraged,
> CONFIG_EXPERT=y should be set. It also gives us the nice property that
> KFENCE will be build-tested by allyesconfig builds.
>
> Co-developed-by: Marco Elver <elver@google.com>
> Signed-off-by: Marco Elver <elver@google.com>
> Signed-off-by: Alexander Potapenko <glider@google.com>
> ---
>  lib/Kconfig.kfence | 2 +-
>  mm/kasan/common.c  | 7 +++++++
>  2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence
> index 7ac91162edb0..b080e49e15d4 100644
> --- a/lib/Kconfig.kfence
> +++ b/lib/Kconfig.kfence
> @@ -10,7 +10,7 @@ config HAVE_ARCH_KFENCE_STATIC_POOL
>
>  menuconfig KFENCE
>         bool "KFENCE: low-overhead sampling-based memory safety error detector"
> -       depends on HAVE_ARCH_KFENCE && !KASAN && (SLAB || SLUB)
> +       depends on HAVE_ARCH_KFENCE && (!KASAN || EXPERT) && (SLAB || SLUB)
>         depends on JUMP_LABEL # To ensure performance, require jump labels
>         select STACKTRACE
>         help
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 950fd372a07e..f5c49f0fdeff 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -18,6 +18,7 @@
>  #include <linux/init.h>
>  #include <linux/kasan.h>
>  #include <linux/kernel.h>
> +#include <linux/kfence.h>
>  #include <linux/kmemleak.h>
>  #include <linux/linkage.h>
>  #include <linux/memblock.h>
> @@ -396,6 +397,9 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
>         tagged_object = object;
>         object = reset_tag(object);
>
> +       if (is_kfence_address(object))
> +               return false;

Is this needed?
At least in the slab patch I see that we do :

if (kfence_free(objp)) {
  kmemleak_free_recursive(objp, cachep->flags);
  return;
}

before:

/* Put the object into the quarantine, don't touch it for now. */ /*
Put the object into the quarantine, don't touch it for now. */
if (kasan_slab_free(cachep, objp, _RET_IP_)) if
(kasan_slab_free(cachep, objp, _RET_IP_))
  return; return;


If it's not supposed to be triggered, it can make sense to replace
with BUG/WARN.


>         if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) !=
>             object)) {
>                 kasan_report_invalid_free(tagged_object, ip);
> @@ -444,6 +448,9 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
>         if (unlikely(object == NULL))
>                 return NULL;
>
> +       if (is_kfence_address(object))
> +               return (void *)object;
> +
>         redzone_start = round_up((unsigned long)(object + size),
>                                 KASAN_SHADOW_SCALE_SIZE);
>         redzone_end = round_up((unsigned long)object + cache->object_size,
> --
> 2.28.0.526.ge36021eeef-goog
>

WARNING: multiple messages have this Message-ID (diff)
From: Dmitry Vyukov <dvyukov@google.com>
To: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Linux-MM <linux-mm@kvack.org>, Eric Dumazet <edumazet@google.com>,
	Alexander Potapenko <glider@google.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Christoph Lameter <cl@linux.com>, Will Deacon <will@kernel.org>,
	Jonathan Corbet <corbet@lwn.net>,
	the arch/x86 maintainers <x86@kernel.org>,
	kasan-dev <kasan-dev@googlegroups.com>,
	Ingo Molnar <mingo@redhat.com>,
	David Rientjes <rientjes@google.com>,
	Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Kees Cook <keescook@chromium.org>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Jann Horn <jannh@google.com>,
	Andrey Konovalov <andreyknvl@google.com>,
	Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Pekka Enberg <penberg@kernel.org>, Qian Cai <cai@lca.pw>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH RFC 06/10] kfence, kasan: make KFENCE compatible with KASAN
Date: Fri, 11 Sep 2020 09:04:54 +0200	[thread overview]
Message-ID: <CACT4Y+b=Ph-fD_K5F_TNMp_dTNjD7GXGT=OXogrKc_HwH+HHwQ@mail.gmail.com> (raw)
In-Reply-To: <20200907134055.2878499-7-elver@google.com>

On Mon, Sep 7, 2020 at 3:41 PM Marco Elver <elver@google.com> wrote:
>
> From: Alexander Potapenko <glider@google.com>
>
> We make KFENCE compatible with KASAN for testing KFENCE itself. In
> particular, KASAN helps to catch any potential corruptions to KFENCE
> state, or other corruptions that may be a result of freepointer
> corruptions in the main allocators.
>
> To indicate that the combination of the two is generally discouraged,
> CONFIG_EXPERT=y should be set. It also gives us the nice property that
> KFENCE will be build-tested by allyesconfig builds.
>
> Co-developed-by: Marco Elver <elver@google.com>
> Signed-off-by: Marco Elver <elver@google.com>
> Signed-off-by: Alexander Potapenko <glider@google.com>
> ---
>  lib/Kconfig.kfence | 2 +-
>  mm/kasan/common.c  | 7 +++++++
>  2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence
> index 7ac91162edb0..b080e49e15d4 100644
> --- a/lib/Kconfig.kfence
> +++ b/lib/Kconfig.kfence
> @@ -10,7 +10,7 @@ config HAVE_ARCH_KFENCE_STATIC_POOL
>
>  menuconfig KFENCE
>         bool "KFENCE: low-overhead sampling-based memory safety error detector"
> -       depends on HAVE_ARCH_KFENCE && !KASAN && (SLAB || SLUB)
> +       depends on HAVE_ARCH_KFENCE && (!KASAN || EXPERT) && (SLAB || SLUB)
>         depends on JUMP_LABEL # To ensure performance, require jump labels
>         select STACKTRACE
>         help
> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> index 950fd372a07e..f5c49f0fdeff 100644
> --- a/mm/kasan/common.c
> +++ b/mm/kasan/common.c
> @@ -18,6 +18,7 @@
>  #include <linux/init.h>
>  #include <linux/kasan.h>
>  #include <linux/kernel.h>
> +#include <linux/kfence.h>
>  #include <linux/kmemleak.h>
>  #include <linux/linkage.h>
>  #include <linux/memblock.h>
> @@ -396,6 +397,9 @@ static bool __kasan_slab_free(struct kmem_cache *cache, void *object,
>         tagged_object = object;
>         object = reset_tag(object);
>
> +       if (is_kfence_address(object))
> +               return false;

Is this needed?
At least in the slab patch I see that we do :

if (kfence_free(objp)) {
  kmemleak_free_recursive(objp, cachep->flags);
  return;
}

before:

/* Put the object into the quarantine, don't touch it for now. */ /*
Put the object into the quarantine, don't touch it for now. */
if (kasan_slab_free(cachep, objp, _RET_IP_)) if
(kasan_slab_free(cachep, objp, _RET_IP_))
  return; return;


If it's not supposed to be triggered, it can make sense to replace
with BUG/WARN.


>         if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) !=
>             object)) {
>                 kasan_report_invalid_free(tagged_object, ip);
> @@ -444,6 +448,9 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
>         if (unlikely(object == NULL))
>                 return NULL;
>
> +       if (is_kfence_address(object))
> +               return (void *)object;
> +
>         redzone_start = round_up((unsigned long)(object + size),
>                                 KASAN_SHADOW_SCALE_SIZE);
>         redzone_end = round_up((unsigned long)object + cache->object_size,
> --
> 2.28.0.526.ge36021eeef-goog
>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2020-09-11  7:05 UTC|newest]

Thread overview: 152+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-07 13:40 [PATCH RFC 00/10] KFENCE: A low-overhead sampling-based memory safety error detector Marco Elver
2020-09-07 13:40 ` Marco Elver
2020-09-07 13:40 ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 01/10] mm: add Kernel Electric-Fence infrastructure Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 15:41   ` Jonathan Cameron
2020-09-07 15:41     ` Jonathan Cameron
2020-09-07 16:38     ` Marco Elver
2020-09-07 16:38       ` Marco Elver
2020-09-07 16:38       ` Marco Elver
2020-09-10 14:57   ` Dmitry Vyukov
2020-09-10 14:57     ` Dmitry Vyukov
2020-09-10 14:57     ` Dmitry Vyukov
2020-09-10 15:06     ` Marco Elver
2020-09-10 15:06       ` Marco Elver
2020-09-10 15:06       ` Marco Elver
2020-09-10 15:48       ` Dmitry Vyukov
2020-09-10 15:48         ` Dmitry Vyukov
2020-09-10 15:48         ` Dmitry Vyukov
2020-09-10 16:22         ` Marco Elver
2020-09-10 16:22           ` Marco Elver
2020-09-10 16:22           ` Marco Elver
2020-09-10 15:42   ` Dmitry Vyukov
2020-09-10 15:42     ` Dmitry Vyukov
2020-09-10 15:42     ` Dmitry Vyukov
2020-09-10 16:19     ` Alexander Potapenko
2020-09-10 16:19       ` Alexander Potapenko
2020-09-10 16:19       ` Alexander Potapenko
2020-09-10 17:11       ` Dmitry Vyukov
2020-09-10 17:11         ` Dmitry Vyukov
2020-09-10 17:11         ` Dmitry Vyukov
2020-09-10 17:41         ` Marco Elver
2020-09-10 17:41           ` Marco Elver
2020-09-10 17:41           ` Marco Elver
2020-09-10 20:25         ` Paul E. McKenney
2020-09-10 20:25           ` Paul E. McKenney
2020-09-15 13:57   ` SeongJae Park
2020-09-15 13:57     ` SeongJae Park
2020-09-15 14:14     ` Marco Elver
2020-09-15 14:14       ` Marco Elver
2020-09-15 14:26       ` SeongJae Park
2020-09-15 14:26         ` SeongJae Park
2020-09-07 13:40 ` [PATCH RFC 02/10] x86, kfence: enable KFENCE for x86 Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 17:31   ` kernel test robot
2020-09-07 13:40 ` [PATCH RFC 03/10] arm64, kfence: enable KFENCE for ARM64 Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-09 15:13   ` Marco Elver
2020-09-09 15:13     ` Marco Elver
2020-09-09 15:13     ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 04/10] mm, kfence: insert KFENCE hooks for SLAB Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-11  7:17   ` Dmitry Vyukov
2020-09-11  7:17     ` Dmitry Vyukov
2020-09-11  7:17     ` Dmitry Vyukov
2020-09-11 12:24     ` Marco Elver
2020-09-11 12:24       ` Marco Elver
2020-09-11 12:24       ` Marco Elver
2020-09-11 13:03       ` Dmitry Vyukov
2020-09-11 13:03         ` Dmitry Vyukov
2020-09-11 13:03         ` Dmitry Vyukov
2020-09-07 13:40 ` [PATCH RFC 05/10] mm, kfence: insert KFENCE hooks for SLUB Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 06/10] kfence, kasan: make KFENCE compatible with KASAN Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 16:11   ` kernel test robot
2020-09-11  7:04   ` Dmitry Vyukov [this message]
2020-09-11  7:04     ` Dmitry Vyukov
2020-09-11  7:04     ` Dmitry Vyukov
2020-09-11 13:00     ` Marco Elver
2020-09-11 13:00       ` Marco Elver
2020-09-11 13:00       ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 07/10] kfence, kmemleak: make KFENCE compatible with KMEMLEAK Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-08 11:53   ` Catalin Marinas
2020-09-08 11:53     ` Catalin Marinas
2020-09-08 12:29     ` Alexander Potapenko
2020-09-08 12:29       ` Alexander Potapenko
2020-09-08 12:29       ` Alexander Potapenko
2020-09-07 13:40 ` [PATCH RFC 08/10] kfence, lockdep: make KFENCE compatible with lockdep Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 09/10] kfence, Documentation: add KFENCE documentation Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 15:33   ` Andrey Konovalov
2020-09-07 15:33     ` Andrey Konovalov
2020-09-07 15:33     ` Andrey Konovalov
2020-09-07 16:33     ` Marco Elver
2020-09-07 16:33       ` Marco Elver
2020-09-07 16:33       ` Marco Elver
2020-09-07 17:55       ` Andrey Konovalov
2020-09-07 17:55         ` Andrey Konovalov
2020-09-07 17:55         ` Andrey Konovalov
2020-09-07 18:16         ` Marco Elver
2020-09-07 18:16           ` Marco Elver
2020-09-07 18:16           ` Marco Elver
2020-09-08 15:54   ` Dave Hansen
2020-09-08 15:54     ` Dave Hansen
2020-09-08 16:14     ` Marco Elver
2020-09-08 16:14       ` Marco Elver
2020-09-11  7:14   ` Dmitry Vyukov
2020-09-11  7:14     ` Dmitry Vyukov
2020-09-11  7:14     ` Dmitry Vyukov
2020-09-11  7:46     ` Marco Elver
2020-09-11  7:46       ` Marco Elver
2020-09-11  7:46       ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 10/10] kfence: add test suite Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 13:40   ` Marco Elver
2020-09-07 18:37   ` kernel test robot
2020-09-08 11:48 ` [PATCH RFC 00/10] KFENCE: A low-overhead sampling-based memory safety error detector Vlastimil Babka
2020-09-08 11:48   ` Vlastimil Babka
2020-09-08 12:16   ` Alexander Potapenko
2020-09-08 12:16     ` Alexander Potapenko
2020-09-08 12:16     ` Alexander Potapenko
2020-09-08 14:40     ` Vlastimil Babka
2020-09-08 14:40       ` Vlastimil Babka
2020-09-08 15:21       ` Marco Elver
2020-09-08 15:21         ` Marco Elver
2020-09-08 14:52 ` Dave Hansen
2020-09-08 14:52   ` Dave Hansen
2020-09-08 15:31   ` Marco Elver
2020-09-08 15:31     ` Marco Elver
2020-09-08 15:36     ` Vlastimil Babka
2020-09-08 15:36       ` Vlastimil Babka
2020-09-08 15:56       ` Marco Elver
2020-09-08 15:56         ` Marco Elver
2020-09-11  7:35         ` Dmitry Vyukov
2020-09-11  7:35           ` Dmitry Vyukov
2020-09-11  7:35           ` Dmitry Vyukov
2020-09-11 12:03           ` Marco Elver
2020-09-11 12:03             ` Marco Elver
2020-09-11 12:03             ` Marco Elver
2020-09-11 13:09             ` Dmitry Vyukov
2020-09-11 13:09               ` Dmitry Vyukov
2020-09-11 13:09               ` Dmitry Vyukov
2020-09-11 13:33               ` Marco Elver
2020-09-11 13:33                 ` Marco Elver
2020-09-11 13:33                 ` Marco Elver
2020-09-11 16:33                 ` Marco Elver
2020-09-11 16:33                   ` Marco Elver
2020-09-11 16:33                   ` Marco Elver
2020-09-08 15:37     ` Dave Hansen
2020-09-08 15:37       ` Dave Hansen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CACT4Y+b=Ph-fD_K5F_TNMp_dTNjD7GXGT=OXogrKc_HwH+HHwQ@mail.gmail.com' \
    --to=dvyukov@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=andreyknvl@google.com \
    --cc=aryabinin@virtuozzo.com \
    --cc=bp@alien8.de \
    --cc=cai@lca.pw \
    --cc=catalin.marinas@arm.com \
    --cc=cl@linux.com \
    --cc=corbet@lwn.net \
    --cc=dave.hansen@linux.intel.com \
    --cc=edumazet@google.com \
    --cc=elver@google.com \
    --cc=glider@google.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=hpa@zytor.com \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=jannh@google.com \
    --cc=kasan-dev@googlegroups.com \
    --cc=keescook@chromium.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mingo@redhat.com \
    --cc=paulmck@kernel.org \
    --cc=penberg@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rientjes@google.com \
    --cc=tglx@linutronix.de \
    --cc=will@kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.