From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754434AbcKHUiC (ORCPT ); Tue, 8 Nov 2016 15:38:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45864 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753889AbcKHUiA (ORCPT ); Tue, 8 Nov 2016 15:38:00 -0500 Date: Tue, 8 Nov 2016 22:37:58 +0200 From: "Michael S. Tsirkin" To: Jiri Slaby Cc: virtualization@lists.linux-foundation.org, Linux kernel mailing list , David Airlie , Gerd Hoffmann , dri-devel@lists.freedesktop.org Subject: Re: BUG: 'list_empty(&vgdev->free_vbufs)' is true! Message-ID: <20161108223153-mutt-send-email-mst@kernel.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 08 Nov 2016 20:38:00 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 07, 2016 at 09:43:24AM +0100, Jiri Slaby wrote: > Hi, > > I can relatively easily reproduce this bug: > BUG: 'list_empty(&vgdev->free_vbufs)' is true! > ------------[ cut here ]------------ > kernel BUG at /home/latest/linux/drivers/gpu/drm/virtio/virtgpu_vq.c:130! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > Modules linked in: > CPU: 1 PID: 355 Comm: kworker/1:2 Not tainted 4.9.0-rc2-next-20161028+ #32 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 > Workqueue: events drm_fb_helper_dirty_work > task: ffff88007b124980 task.stack: ffff88007b8a0000 > RIP: 0010:virtio_gpu_get_vbuf+0x32e/0x630 > RSP: 0018:ffff88007b8a78c0 EFLAGS: 00010286 > RAX: 000000000000002e RBX: 1ffff1000f714f1d RCX: 0000000000000000 > RDX: 000000000000002e RSI: 0000000000000001 RDI: ffffed000f714f0e > RBP: ffff88007b8a7970 R08: 0000000000000001 R09: 0000000000000000 > R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000030 > R13: ffff88007caeaba8 R14: 0000000000000018 R15: ffff88007cae0000 > FS: 0000000000000000(0000) GS:ffff88007dc80000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000601028 CR3: 000000007740d000 CR4: 00000000000006e0 > Call Trace: > Code: df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 bb 01 00 00 4c 89 69 e8 > eb 9e 48 c7 c6 e0 d2 d1 83 48 c7 c7 20 d3 d1 83 e8 6c fb 04 ff <0f> 0b > 48 c7 c7 a0 fb b0 85 e8 09 95 86 ff 48 c7 c6 c0 d3 d1 83 > RIP: virtio_gpu_get_vbuf+0x32e/0x630 RSP: ffff88007b8a78c0 > > > There is no stacktrace, as the kernel starts panicing all over the place > during its generation. Any ideas? > > thanks, CC maintainers. The following might be helpful for debugging - if kernel still will not stop panicing, we are looking at some kind of memory corruption. diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c index 5a0f8a7..d5e1e72 100644 --- a/drivers/gpu/drm/virtio/virtgpu_vq.c +++ b/drivers/gpu/drm/virtio/virtgpu_vq.c @@ -127,7 +127,11 @@ virtio_gpu_get_vbuf(struct virtio_gpu_device *vgdev, struct virtio_gpu_vbuffer *vbuf; spin_lock(&vgdev->free_vbufs_lock); - BUG_ON(list_empty(&vgdev->free_vbufs)); + WARN_ON(list_empty(&vgdev->free_vbufs)); + if (list_empty(&vgdev->free_vbufs)) { + spin_unlock(&vgdev->free_vbufs_lock); + return ERR_PTR(-EINVAL); + } vbuf = list_first_entry(&vgdev->free_vbufs, struct virtio_gpu_vbuffer, list); list_del(&vbuf->list); From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: BUG: 'list_empty(&vgdev->free_vbufs)' is true! Date: Tue, 8 Nov 2016 22:37:58 +0200 Message-ID: <20161108223153-mutt-send-email-mst@kernel.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id D23126E5C9 for ; Tue, 8 Nov 2016 20:38:00 +0000 (UTC) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Jiri Slaby Cc: Gerd Hoffmann , Linux kernel mailing list , dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org List-Id: dri-devel@lists.freedesktop.org T24gTW9uLCBOb3YgMDcsIDIwMTYgYXQgMDk6NDM6MjRBTSArMDEwMCwgSmlyaSBTbGFieSB3cm90 ZToKPiBIaSwKPiAKPiBJIGNhbiByZWxhdGl2ZWx5IGVhc2lseSByZXByb2R1Y2UgdGhpcyBidWc6 Cj4gQlVHOiAnbGlzdF9lbXB0eSgmdmdkZXYtPmZyZWVfdmJ1ZnMpJyBpcyB0cnVlIQo+IC0tLS0t LS0tLS0tLVsgY3V0IGhlcmUgXS0tLS0tLS0tLS0tLQo+IGtlcm5lbCBCVUcgYXQgL2hvbWUvbGF0 ZXN0L2xpbnV4L2RyaXZlcnMvZ3B1L2RybS92aXJ0aW8vdmlydGdwdV92cS5jOjEzMCEKPiBpbnZh bGlkIG9wY29kZTogMDAwMCBbIzFdIFBSRUVNUFQgU01QIEtBU0FOCj4gTW9kdWxlcyBsaW5rZWQg aW46Cj4gQ1BVOiAxIFBJRDogMzU1IENvbW06IGt3b3JrZXIvMToyIE5vdCB0YWludGVkIDQuOS4w LXJjMi1uZXh0LTIwMTYxMDI4KyAjMzIKPiBIYXJkd2FyZSBuYW1lOiBRRU1VIFN0YW5kYXJkIFBD IChpNDQwRlggKyBQSUlYLCAxOTk2KSwgQklPUwo+IHJlbC0xLjkuMy0wLWdlMmZjNDFlLXByZWJ1 aWx0LnFlbXUtcHJvamVjdC5vcmcgMDQvMDEvMjAxNAo+IFdvcmtxdWV1ZTogZXZlbnRzIGRybV9m Yl9oZWxwZXJfZGlydHlfd29yawo+IHRhc2s6IGZmZmY4ODAwN2IxMjQ5ODAgdGFzay5zdGFjazog ZmZmZjg4MDA3YjhhMDAwMAo+IFJJUDogMDAxMDp2aXJ0aW9fZ3B1X2dldF92YnVmKzB4MzJlLzB4 NjMwCj4gUlNQOiAwMDE4OmZmZmY4ODAwN2I4YTc4YzAgRUZMQUdTOiAwMDAxMDI4Ngo+IFJBWDog MDAwMDAwMDAwMDAwMDAyZSBSQlg6IDFmZmZmMTAwMGY3MTRmMWQgUkNYOiAwMDAwMDAwMDAwMDAw MDAwCj4gUkRYOiAwMDAwMDAwMDAwMDAwMDJlIFJTSTogMDAwMDAwMDAwMDAwMDAwMSBSREk6IGZm ZmZlZDAwMGY3MTRmMGUKPiBSQlA6IGZmZmY4ODAwN2I4YTc5NzAgUjA4OiAwMDAwMDAwMDAwMDAw MDAxIFIwOTogMDAwMDAwMDAwMDAwMDAwMAo+IFIxMDogMDAwMDAwMDAwMDAwMDAwMiBSMTE6IDAw MDAwMDAwMDAwMDAwMDEgUjEyOiAwMDAwMDAwMDAwMDAwMDMwCj4gUjEzOiBmZmZmODgwMDdjYWVh YmE4IFIxNDogMDAwMDAwMDAwMDAwMDAxOCBSMTU6IGZmZmY4ODAwN2NhZTAwMDAKPiBGUzogIDAw MDAwMDAwMDAwMDAwMDAoMDAwMCkgR1M6ZmZmZjg4MDA3ZGM4MDAwMCgwMDAwKSBrbmxHUzowMDAw MDAwMDAwMDAwMDAwCj4gQ1M6ICAwMDEwIERTOiAwMDAwIEVTOiAwMDAwIENSMDogMDAwMDAwMDA4 MDA1MDAzMwo+IENSMjogMDAwMDAwMDAwMDYwMTAyOCBDUjM6IDAwMDAwMDAwNzc0MGQwMDAgQ1I0 OiAwMDAwMDAwMDAwMDAwNmUwCj4gQ2FsbCBUcmFjZToKPiBDb2RlOiBkZiA0OCA4OSBmYSA0OCBj MSBlYSAwMyA4MCAzYyAwMiAwMCAwZiA4NSBiYiAwMSAwMCAwMCA0YyA4OSA2OSBlOAo+IGViIDll IDQ4IGM3IGM2IGUwIGQyIGQxIDgzIDQ4IGM3IGM3IDIwIGQzIGQxIDgzIGU4IDZjIGZiIDA0IGZm IDwwZj4gMGIKPiA0OCBjNyBjNyBhMCBmYiBiMCA4NSBlOCAwOSA5NSA4NiBmZiA0OCBjNyBjNiBj MCBkMyBkMSA4Mwo+IFJJUDogdmlydGlvX2dwdV9nZXRfdmJ1ZisweDMyZS8weDYzMCBSU1A6IGZm ZmY4ODAwN2I4YTc4YzAKPiAKPiAKPiBUaGVyZSBpcyBubyBzdGFja3RyYWNlLCBhcyB0aGUga2Vy bmVsIHN0YXJ0cyBwYW5pY2luZyBhbGwgb3ZlciB0aGUgcGxhY2UKPiBkdXJpbmcgaXRzIGdlbmVy YXRpb24uIEFueSBpZGVhcz8KPiAKPiB0aGFua3MsCgpDQyBtYWludGFpbmVycy4KClRoZSBmb2xs b3dpbmcgbWlnaHQgYmUgaGVscGZ1bCBmb3IgZGVidWdnaW5nIC0gaWYga2VybmVsIHN0aWxsIHdp bGwKbm90IHN0b3AgcGFuaWNpbmcsIHdlIGFyZSBsb29raW5nIGF0IHNvbWUga2luZApvZiBtZW1v cnkgY29ycnVwdGlvbi4KCgpkaWZmIC0tZ2l0IGEvZHJpdmVycy9ncHUvZHJtL3ZpcnRpby92aXJ0 Z3B1X3ZxLmMgYi9kcml2ZXJzL2dwdS9kcm0vdmlydGlvL3ZpcnRncHVfdnEuYwppbmRleCA1YTBm OGE3Li5kNWUxZTcyIDEwMDY0NAotLS0gYS9kcml2ZXJzL2dwdS9kcm0vdmlydGlvL3ZpcnRncHVf dnEuYworKysgYi9kcml2ZXJzL2dwdS9kcm0vdmlydGlvL3ZpcnRncHVfdnEuYwpAQCAtMTI3LDcg KzEyNywxMSBAQCB2aXJ0aW9fZ3B1X2dldF92YnVmKHN0cnVjdCB2aXJ0aW9fZ3B1X2RldmljZSAq dmdkZXYsCiAJc3RydWN0IHZpcnRpb19ncHVfdmJ1ZmZlciAqdmJ1ZjsKIAogCXNwaW5fbG9jaygm dmdkZXYtPmZyZWVfdmJ1ZnNfbG9jayk7Ci0JQlVHX09OKGxpc3RfZW1wdHkoJnZnZGV2LT5mcmVl X3ZidWZzKSk7CisJV0FSTl9PTihsaXN0X2VtcHR5KCZ2Z2Rldi0+ZnJlZV92YnVmcykpOworCWlm IChsaXN0X2VtcHR5KCZ2Z2Rldi0+ZnJlZV92YnVmcykpIHsKKwkJc3Bpbl91bmxvY2soJnZnZGV2 LT5mcmVlX3ZidWZzX2xvY2spOworCQlyZXR1cm4gRVJSX1BUUigtRUlOVkFMKTsKKwl9CiAJdmJ1 ZiA9IGxpc3RfZmlyc3RfZW50cnkoJnZnZGV2LT5mcmVlX3ZidWZzLAogCQkJCXN0cnVjdCB2aXJ0 aW9fZ3B1X3ZidWZmZXIsIGxpc3QpOwogCWxpc3RfZGVsKCZ2YnVmLT5saXN0KTsKX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVsIG1haWxpbmcg bGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRl c2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg==