From: Vladimir Davydov <vdavydov@tarantool.org>
To: Greg Thelen <gthelen@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] kasan: add memcg kmem_cache test
Date: Thu, 22 Dec 2016 11:56:37 +0300 [thread overview]
Message-ID: <20161222085637.GB3494@esperanza> (raw)
In-Reply-To: <1482257462-36948-2-git-send-email-gthelen@google.com>
On Tue, Dec 20, 2016 at 10:11:02AM -0800, Greg Thelen wrote:
> Make a kasan test which uses a SLAB_ACCOUNT slab cache. If the test is
> run within a non default memcg, then it uncovers the bug fixed by
> "kasan: drain quarantine of memcg slab objects"[1].
>
> If run without fix [1] it shows "Slab cache still has objects", and the
> kmem_cache structure is leaked.
> Here's an unpatched kernel test:
> $ dmesg -c > /dev/null
> $ mkdir /sys/fs/cgroup/memory/test
> $ echo $$ > /sys/fs/cgroup/memory/test/tasks
> $ modprobe test_kasan 2> /dev/null
> $ dmesg | grep -B1 still
> [ 123.456789] kasan test: memcg_accounted_kmem_cache allocate memcg accounted object
> [ 124.456789] kmem_cache_destroy test_cache: Slab cache still has objects
>
> Kernels with fix [1] don't have the "Slab cache still has objects"
> warning or the underlying leak.
>
> The new test runs and passes in the default (root) memcg, though in the
> root memcg it won't uncover the problem fixed by [1].
>
> Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
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WARNING: multiple messages have this Message-ID (diff)
From: Vladimir Davydov <vdavydov@tarantool.org>
To: Greg Thelen <gthelen@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] kasan: add memcg kmem_cache test
Date: Thu, 22 Dec 2016 11:56:37 +0300 [thread overview]
Message-ID: <20161222085637.GB3494@esperanza> (raw)
In-Reply-To: <1482257462-36948-2-git-send-email-gthelen@google.com>
On Tue, Dec 20, 2016 at 10:11:02AM -0800, Greg Thelen wrote:
> Make a kasan test which uses a SLAB_ACCOUNT slab cache. If the test is
> run within a non default memcg, then it uncovers the bug fixed by
> "kasan: drain quarantine of memcg slab objects"[1].
>
> If run without fix [1] it shows "Slab cache still has objects", and the
> kmem_cache structure is leaked.
> Here's an unpatched kernel test:
> $ dmesg -c > /dev/null
> $ mkdir /sys/fs/cgroup/memory/test
> $ echo $$ > /sys/fs/cgroup/memory/test/tasks
> $ modprobe test_kasan 2> /dev/null
> $ dmesg | grep -B1 still
> [ 123.456789] kasan test: memcg_accounted_kmem_cache allocate memcg accounted object
> [ 124.456789] kmem_cache_destroy test_cache: Slab cache still has objects
>
> Kernels with fix [1] don't have the "Slab cache still has objects"
> warning or the underlying leak.
>
> The new test runs and passes in the default (root) memcg, though in the
> root memcg it won't uncover the problem fixed by [1].
>
> Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com>
next prev parent reply other threads:[~2016-12-22 8:56 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-20 18:11 [PATCH 1/2] kasan: drain quarantine of memcg slab objects Greg Thelen
2016-12-20 18:11 ` Greg Thelen
2016-12-20 18:11 ` [PATCH 2/2] kasan: add memcg kmem_cache test Greg Thelen
2016-12-20 18:11 ` Greg Thelen
2016-12-22 8:56 ` Vladimir Davydov [this message]
2016-12-22 8:56 ` Vladimir Davydov
2016-12-21 16:42 ` [PATCH 1/2] kasan: drain quarantine of memcg slab objects Andrey Ryabinin
2016-12-21 16:42 ` Andrey Ryabinin
2016-12-22 8:54 ` Vladimir Davydov
2016-12-22 8:54 ` Vladimir Davydov
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