Re: [PATCH 1/2] x86: Check return values from early_memremap calls

From: Jan Kiszka
Date: Mon Oct 10 2022 - 04:46:57 EST


On 08.10.22 17:12, Borislav Petkov wrote:
> Adding Xen and Jailhouse people and MLs to Cc.
>
> Folks, thread starts here:
>
> https://lore.kernel.org/r/1650035401-22855-1-git-send-email-ross.philipson@xxxxxxxxxx
>
> On Fri, Apr 15, 2022 at 11:10:00AM -0400, Ross Philipson wrote:
>> There are a number of places where early_memremap is called
>> but the return pointer is not checked for NULL. The call
>> can result in a NULL being returned so the checks must
>> be added.
>>
>> Signed-off-by: Ross Philipson <ross.philipson@xxxxxxxxxx>
>> ---
>> arch/x86/kernel/devicetree.c | 10 ++++++++++
>> arch/x86/kernel/e820.c | 5 +++++
>> arch/x86/kernel/jailhouse.c | 6 ++++++
>> arch/x86/kernel/mpparse.c | 23 +++++++++++++++++++++++
>> arch/x86/kernel/setup.c | 5 +++++
>> arch/x86/xen/enlighten_hvm.c | 2 ++
>> arch/x86/xen/mmu_pv.c | 8 ++++++++
>> arch/x86/xen/setup.c | 2 ++
>> 8 files changed, 61 insertions(+)
>
> Ok, a couple of notes:
>
> 1. the pr_*("<prefix>:" ... )
>
> thing is done using pr_fmt() - grep the tree for examples.
>
> 2. I think you should not panic() the machine but issue a the
> warning/error and let the machine die a painful death anyway. But Xen
> folks will know better what would be the optimal thing to do.
>
> Thx.
>

For the Jailhouse bits:

Reviewed-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>

(IOW, panic'ing is fine for us here)

Thanks,
Jan

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