From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
paulus@samba.org, mpe@ellerman.id.au,
linuxppc-dev@lists.ozlabs.org,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH V2 09/10] kasan: Prevent deadlock in kasan reporting
Date: Sun, 30 Aug 2015 18:23:02 +0530 [thread overview]
Message-ID: <8737z1q6oh.fsf@linux.vnet.ibm.com> (raw)
In-Reply-To: <CAPAsAGwhV6tr3byk8kgjTxrLS0kKoyhoW8AUAXkjLVOaUbuVUA@mail.gmail.com>
Andrey Ryabinin <ryabinin.a.a@gmail.com> writes:
> 2015-08-26 11:26 GMT+03:00 Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>:
>> We we end up calling kasan_report in real mode, our shadow mapping
>> for even spinlock variable will show poisoned.
>
> Generally I agree with this patch. We should disable reports when we
> print report as early
> as possible to prevent recursion in case of bug in spinlock or printk etc.
>
> But I don't understand what is the problem that you observing.
> How we ended up with shadow poisoned for a valid spinlock struct?
> And since shadow poisoned for some valid memory we should get
> enormous amount of false positive reports.
>
I still haven't fully isolated all the .c files which should not be
kasan instrumented. That means in case of ppc64 i ended up calling
kasan _load/_store in real mode. That will result in failure w.r.t
to the above spin_lock code.
-aneesh
next prev parent reply other threads:[~2015-08-30 12:53 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-26 8:26 [PATCH V2 00/10] KASan ppc64 support Aneesh Kumar K.V
2015-08-26 8:26 ` [PATCH V2 01/10] powerpc/mm: Add virt_to_pfn and use this instead of opencoding Aneesh Kumar K.V
2015-08-26 8:26 ` [PATCH V2 02/10] kasan: MODULE_VADDR is not available on all archs Aneesh Kumar K.V
2015-08-26 17:00 ` Andrey Ryabinin
2015-08-30 12:33 ` Aneesh Kumar K.V
2015-08-26 8:26 ` [PATCH V2 03/10] kasan: Rename kasan_enabled to kasan_report_enabled Aneesh Kumar K.V
2015-08-26 17:02 ` Andrey Ryabinin
2015-08-26 8:26 ` [PATCH V2 04/10] kasan: Don't use kasan shadow pointer in generic functions Aneesh Kumar K.V
2015-08-26 8:54 ` Aneesh Kumar K.V
2015-08-27 9:42 ` Andrey Ryabinin
2015-08-26 8:26 ` [PATCH V2 05/10] kasan: Enable arch to hook into kasan callbacks Aneesh Kumar K.V
2015-08-27 9:46 ` Andrey Ryabinin
2015-08-30 12:41 ` Aneesh Kumar K.V
2015-08-26 8:26 ` [PATCH V2 06/10] kasan: Allow arch to overrride kasan shadow offsets Aneesh Kumar K.V
2015-08-27 9:48 ` Andrey Ryabinin
2015-08-26 8:26 ` [PATCH V2 07/10] kasan: Make INLINE KASan support arch selectable Aneesh Kumar K.V
2015-08-27 11:55 ` Andrey Ryabinin
2015-08-30 12:50 ` Aneesh Kumar K.V
2015-08-26 8:26 ` [PATCH V2 08/10] kasan: Update feature support file Aneesh Kumar K.V
2015-08-26 8:26 ` [PATCH V2 09/10] kasan: Prevent deadlock in kasan reporting Aneesh Kumar K.V
2015-08-27 12:08 ` Andrey Ryabinin
2015-08-30 12:53 ` Aneesh Kumar K.V [this message]
2015-08-26 8:26 ` [PATCH V2 10/10] powerpc/mm: kasan: Add kasan support for ppc64 Aneesh Kumar K.V
2015-08-27 12:16 ` Andrey Ryabinin
2015-08-26 16:37 ` [PATCH V2 00/10] KASan ppc64 support Andrey Ryabinin
2015-08-26 17:14 ` Aneesh Kumar K.V
2018-07-05 16:33 ` Christophe LEROY
2018-07-06 14:11 ` Aneesh Kumar K.V
2018-07-06 14:13 ` Christophe LEROY
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