Re: [PATCH] virtio_blk: avoid DMA to stack for the sense buffer

[çéæ]

2017-01-05 10:57 GMT+01:00 Christoph Hellwig <hch@xxxxxx>:
> On Wed, Jan 04, 2017 at 04:47:03PM +0100, çéæ wrote:
>> This sounds scary.
>> Could you share how to reproduce it, this should go into stable if
>> it's the case.
>
> Step 1: Build your kernel with CONFIG_VMAP_STACK=y
> Step 2: issue a SG_IO ioctl, e.g. sg_inq /dev/vda
>
Thanks, so it's only relevant to kernel > 4.9, as  CONFIG_VMAP_STACK
only introduced in 4.9 kernel.

Regards,
Jinpu