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From:   Chia-I Wu <olvaffe@gmail.com>
Date:   Tue, 23 May 2023 15:36:00 -0700
Message-ID: <CAPaKu7Rsn-Uiaf6z4VGbhcwuiKeqX0dK5kJZJgs287XHtQcoig@mail.gmail.com>
Subject: Re: [PATCH 1/2] amdgpu: validate drm_amdgpu_gem_va addrs for all ops
To:     =?UTF-8?Q?Christian_K=C3=B6nig?= <ckoenig.leichtzumerken@gmail.com>
Cc:     Alex Deucher <alexdeucher@gmail.com>,
        Philip Yang <Philip.Yang@amd.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>,
        Felix Kuehling <Felix.Kuehling@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        Danijel Slivka <danijel.slivka@amd.com>,
        linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
        Mukul Joshi <mukul.joshi@amd.com>,
        Luben Tuikov <luben.tuikov@amd.com>,
        Yang Li <yang.lee@linux.alibaba.com>,
        dri-devel@lists.freedesktop.org,
        Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        Suren Baghdasaryan <surenb@google.com>,
        =?UTF-8?B?TWFyZWsgT2zFocOhaw==?= <marek.olsak@amd.com>
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On Mon, May 22, 2023 at 12:12=E2=80=AFPM Christian K=C3=B6nig
<ckoenig.leichtzumerken@gmail.com> wrote:
>
> Am 21.05.23 um 20:49 schrieb Chia-I Wu:
> > On Thu, May 18, 2023 at 1:12=E2=80=AFPM Alex Deucher <alexdeucher@gmail=
.com> wrote:
> >> On Wed, May 17, 2023 at 5:27=E2=80=AFPM Chia-I Wu <olvaffe@gmail.com> =
wrote:
> >>> On Tue, May 9, 2023 at 11:33=E2=80=AFAM Chia-I Wu <olvaffe@gmail.com>=
 wrote:
> >>>> Extend the address and size validations to AMDGPU_VA_OP_UNMAP and
> >>>> AMDGPU_VA_OP_CLEAR by moving the validations to amdgpu_gem_va_ioctl.
> >>>>
> >>>> Internal users of amdgpu_vm_bo_map are no longer validated but they
> >>>> should be fine.
> >>>>
> >>>> Userspace (radeonsi and radv) seems fine as well.
> >>> Does this series make sense?
> >> I think so, I haven't had a chance to go through this too closely yet,
> >> but amdgpu_vm_bo_map() is used by ROCm as well so we'd need to make
> >> sure that removing the checks in patch 1 wouldn't affect that path as
> >> well.  The changes in patch 2 look good.  Also, these patches are
> >> missing your SOB.
> > Indeed.  kfd_ioctl_alloc_memory_of_gpu, for example, does not validate
> > va.  I need to keep the validation in amdgpu_vm_bo_map for it at
> > least.  I guess it is more ideal for kfd_ioctl_alloc_memory_of_gpu to
> > validate, but I am not familiar with amdkfd..
> >
> > I can keep the existing validations, and duplicate them in
> > amdgpu_gem_va_ioctl to cover AMDGPU_VA_OP_UNMAP/AMDGPU_VA_OP_CLEAR.
>
> The key point is that unmap and clear don't need those validations.
>
> It's perfectly valid to request unmap of an unaligned mapping, it will
> just fail because we can't find that mapping.
unmap and clear_mappings convert addresses to gpu pages so unaligned
addresses are treated as if they were aligned.  That's likely fine
except that might be an unintentional inconsistency between va ops?

When args->map_size is 0, eaddr can be smaller than saddr in
clear_mappings.  We are also at the mercy of how interval trees are
implemented.

>
> Regards,
> Christian.
>
> >
> >> Thanks,
> >>
> >> Alex
> >>
> >>
> >> Alex
>