linux-kernel - Re: [PATCH v2 1/7] xen: use correct end address of kernel for conflict checking

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Message-ID: <41837bb1-0251-4250-8f00-23d60cb1d664@suse.com>
Date: Tue, 20 Aug 2024 10:29:00 +0200
From: Jan Beulich <jbeulich@...e.com>
To: Juergen Gross <jgross@...e.com>
Cc: Boris Ostrovsky <boris.ostrovsky@...cle.com>,
 Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
 Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>,
 "H. Peter Anvin" <hpa@...or.com>, xen-devel@...ts.xenproject.org,
 Marek Marczykowski-Górecki
 <marmarek@...isiblethingslab.com>, linux-kernel@...r.kernel.org,
 x86@...nel.org
Subject: Re: [PATCH v2 1/7] xen: use correct end address of kernel for
 conflict checking

On 20.08.2024 10:20, Juergen Gross wrote:
> When running as a Xen PV dom0 the kernel is loaded by the hypervisor
> using a different memory map than that of the host. In order to
> minimize the required changes in the kernel, the kernel adapts its
> memory map to that of the host. In order to do that it is checking
> for conflicts of its load address with the host memory map.
> 
> Unfortunately the tested memory range does not include the .brk
> area, which might result in crashes or memory corruption when this
> area does conflict withe the memory map of the host.
> 
> Fix the test by using the _end label instead of __bss_stop.
> 
> Fixes: 808fdb71936c ("xen: check for kernel memory conflicting with memory layout")
> 
> Signed-off-by: Juergen Gross <jgross@...e.com>
> Tested-by: Marek Marczykowski-Górecki <marmarek@...isiblethingslab.com>

Reviewed-by: Jan Beulich <jbeulich@...e.com>