From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@citrix.com>
Subject: Re: xen/arm: Crash when allocating memory for ACPI
 table (Was Re: Design doc of adding ACPI support for arm64 on Xen - version
 2)
Date: Fri, 14 Aug 2015 15:53:17 +0100
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To: Shannon Zhao <shannon.zhao@linaro.org>, Shannon Zhao <zhaoshenglong@huawei.com>, xen-devel <xen-devel@lists.xen.org>, Jan Beulich <jbeulich@suse.com>, Stefano Stabellini <stefano.stabellini@citrix.com>, Ian Campbell <ian.campbell@citrix.com>, Parth Dixit <parth.dixit@linaro.org>, Christoffer Dall <christoffer.dall@linaro.org>
Cc: Hangaohuai <hangaohuai@huawei.com>, "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
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On 14/08/15 15:49, Shannon Zhao wrote:
>> Ok, so it's likely a memory corruption. You need to check the bound you
>> ara using when copying the data to the guest or from the ACPI in
>> general. Or maybe you just didn't allocate enough space.
>>
> 
> But it fails at the xzalloc_bytes itself. not at copy function.

Because the previous copy may have overwritten the metadata of the
memory allocator...

If those metadata are corrupted, xalloc_bytes we act weirdly such as
crashing Xen.

Regards,

-- 
Julien Grall