[Nouveau] [PATCH] drm/nouveau: properly handle pushbuffer check failures

[Maarten Maathuis]

On Mon, Mar 7, 2011 at 11:31 AM, Marcin Slusarz
<marcin.slusarz at gmail.com> wrote:
> When "buffer in list" check does not pass, don't free validation lists - they were
> not initialized yet.
>
> Fixes this oops:
>
> [drm] nouveau 0000:02:00.0: push 105 buffer not in list
> BUG: unable to handle kernel NULL pointer dereference at 000000000000057c
> IP: [<ffffffff81236aa4>] do_raw_spin_lock+0x14/0x13c
> PGD 1ac6cb067 PUD 1aaa52067 PMD 0
> CPU 0
> Modules linked in: nouveau ttm drm_kms_helper snd_hda_codec_realtek snd_hda_intel snd_hda_codec
>
> Pid: 6265, comm: OilRush_x86 Not tainted 2.6.38-rc6-nv+ #632 System manufacturer System Product Name/P6T SE
> RIP: 0010:[<ffffffff81236aa4>]  [<ffffffff81236aa4>] do_raw_spin_lock+0x14/0x13c
> (...)
> Process OilRush_x86 (pid: 6265, threadinfo ffff8801a6aee000, task ffff8801a26c0000)
>  0000000000000000 ffff8801ac74c618 0000000000000000 0000000000000578
>  0000000000000000 ffff8801ac74c618 0000000000000000 ffff8801bd9d0000
>  [<ffffffff81417f78>] _raw_spin_lock+0x1e/0x22
>  [<ffffffffa00a2746>] nouveau_bo_fence+0x2e/0x60 [nouveau]
>  [<ffffffffa00a540b>] validate_fini_list+0x35/0xeb [nouveau]
>  [<ffffffffa00a54d3>] validate_fini+0x12/0x31 [nouveau]
>  [<ffffffffa00a6386>] nouveau_gem_ioctl_pushbuf+0xe94/0xf6b [nouveau]
>  [<ffffffff8141ac56>] ? sub_preempt_count+0x9e/0xb2
>  [<ffffffff81417e94>] ? _raw_spin_unlock_irqrestore+0x30/0x4d
>  [<ffffffff8105dea2>] ? __wake_up+0x3f/0x48
>  [<ffffffff812aebb4>] drm_ioctl+0x289/0x361
>  [<ffffffff8141ac56>] ? sub_preempt_count+0x9e/0xb2
>  [<ffffffffa00a54f2>] ? nouveau_gem_ioctl_pushbuf+0x0/0xf6b [nouveau]
>  [<ffffffff8141ac56>] ? sub_preempt_count+0x9e/0xb2
>  [<ffffffffa010caa2>] nouveau_compat_ioctl+0x16/0x1c [nouveau]
>  [<ffffffff81142c0d>] compat_sys_ioctl+0x1c8/0x12d7
>  [<ffffffff814179ca>] ? trace_hardirqs_off_thunk+0x3a/0x6c
>  [<ffffffff81058099>] sysenter_dispatch+0x7/0x30
>  [<ffffffff8141798e>] ? trace_hardirqs_on_thunk+0x3a/0x3c
> RIP  [<ffffffff81236aa4>] do_raw_spin_lock+0x14/0x13c
>  RSP <ffff8801a6aefb88>
> ---[ end trace 0014d5d93e6147e1 ]---
>
> Additionally, don't call validate_fini twice in case of validation failure.
>
> Signed-off-by: Marcin Slusarz <marcin.slusarz at gmail.com>
> ---
>  drivers/gpu/drm/nouveau/nouveau_gem.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
> index 3ce58d2..e8b04f4 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
> @@ -600,7 +600,7 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data,
>                if (push[i].bo_index >= req->nr_buffers) {
>                        NV_ERROR(dev, "push %d buffer not in list\n", i);
>                        ret = -EINVAL;
> -                       goto out;
> +                       goto out_prevalid;
>                }
>
>                bo[push[i].bo_index].read_domains |= (1 << 31);
> @@ -612,7 +612,7 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data,
>        if (ret) {
>                if (ret != -ERESTARTSYS)
>                        NV_ERROR(dev, "validate: %d\n", ret);
> -               goto out;
> +               goto out_prevalid;
>        }
>
>        /* Apply any relocations that are required */
> @@ -705,6 +705,8 @@ nouveau_gem_ioctl_pushbuf(struct drm_device *dev, void *data,
>  out:
>        validate_fini(&op, fence);
>        nouveau_fence_unref(&fence);
> +
> +out_prevalid:
>        kfree(bo);
>        kfree(push);
>
> --
> 1.7.4.rc3
>
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> http://lists.freedesktop.org/mailman/listinfo/nouveau
>

This seems a simple fix, so i pushed it.

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