From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1253E7D0A9 for ; Thu, 21 Sep 2023 20:26:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231869AbjIUU1C (ORCPT ); Thu, 21 Sep 2023 16:27:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231603AbjIUU01 (ORCPT ); Thu, 21 Sep 2023 16:26:27 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2E567356B; Thu, 21 Sep 2023 10:33:16 -0700 (PDT) Received: from [IPV6:2a01:e0a:120:3210:9fdf:789a:7434:5a59] (unknown [IPv6:2a01:e0a:120:3210:9fdf:789a:7434:5a59]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: benjamin.gaignard) by madras.collabora.co.uk (Postfix) with ESMTPSA id 33A2566072EA; Thu, 21 Sep 2023 13:46:43 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1695300403; bh=LVEZ1RsG9zACgcHPee3WTOL671cvZoROVfJ92IP6s4Y=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Z7acJaSzlHDcCiwLMiECWrrw5UijdlQ+DYiCsWekWoNpZ3tWGx6RqitZQ5cmt7bpf r8MU3UuFwvDJzNYe1xL5Y/b3xLsQy0Phe/0FacTfJDAd76T/xFvJsFSKXzdi7cqygT nnR/uVG3c5M9+pdpeUljAGo+Ro7bh3NzUCc7J3/ZVMKPQmZV5Ar34/V7nSYyhf7xVi RjGOqVm5mGQxUBr22OlVpTmp3jupc+1vblk/eBLz/A9XDq3XaZ2d0hvxOepERS1ZdT 9mjN13gH3bQTbVtxurYBzMHh5jfHpAcMC56+t7Ip6d0FjST8TjTAN+DXWqnN9PFxMc NU4rD8cbt2+6g== Message-ID: Date: Thu, 21 Sep 2023 14:46:40 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH v7 45/49] media: core: Add bitmap manage bufs array entries Content-Language: en-US To: Hans Verkuil , mchehab@kernel.org, tfiga@chromium.org, m.szyprowski@samsung.com, ming.qian@nxp.com, ezequiel@vanguardiasur.com.ar, p.zabel@pengutronix.de, gregkh@linuxfoundation.org, nicolas.dufresne@collabora.com Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-staging@lists.linux.dev, kernel@collabora.com References: <20230914133323.198857-1-benjamin.gaignard@collabora.com> <20230914133323.198857-46-benjamin.gaignard@collabora.com> <1142bbb4-b8f1-44ec-962e-9347a231782f@xs4all.nl> <20b6b93e-eef8-3d7b-a3c2-795f220059d4@collabora.com> <470682b4-c14b-4237-bc46-fddfdd085026@xs4all.nl> <31f298ec-6280-d21b-3d8a-c7bf1c9c0c30@collabora.com> From: Benjamin Gaignard In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 21/09/2023 à 14:13, Hans Verkuil a écrit : > On 21/09/2023 14:05, Benjamin Gaignard wrote: >> Le 21/09/2023 à 12:24, Hans Verkuil a écrit : >>> On 21/09/2023 11:28, Benjamin Gaignard wrote: >>>> Le 20/09/2023 à 16:56, Hans Verkuil a écrit : >>>>> On 20/09/2023 16:30, Benjamin Gaignard wrote: >>>>> >>>>> >>>>>>>>         num_buffers = min_t(unsigned int, num_buffers, >>>>>>>>                     q->max_allowed_buffers - vb2_get_num_buffers(q)); >>>>>>>>     -    first_index = vb2_get_num_buffers(q); >>>>>>>> +    first_index = bitmap_find_next_zero_area(q->bufs_map, q->max_allowed_buffers, >>>>>>>> +                         0, num_buffers, 0); >>>>>>>>           if (first_index >= q->max_allowed_buffers) >>>>>>>>             return 0; >>>>>>>> @@ -675,7 +678,13 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers) >>>>>>>>       struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q, unsigned int index) >>>>>>>>     { >>>>>>>> -    if (index < q->num_buffers) >>>>>>>> +    if (!q->bufs_map || !q->bufs) >>>>>>>> +        return NULL; >>>>>>> I don't think this can ever happen. >>>>>> I got kernel crash without them. >>>>>> I will keep them. >>>>> What is the backtrace? How can this happen? It feels wrong that this can be >>>>> called with a vb2_queue that apparently is not properly initialized. >>>> I have this log when adding dump_stack() in vb2_get_buffer() if !q->bufs_bitmap: >>>> >>>> [   18.924627] Call trace: >>>> [   18.927090]  dump_backtrace+0x94/0xec >>>> [   18.930787]  show_stack+0x18/0x24 >>>> [   18.934137]  dump_stack_lvl+0x48/0x60 >>>> [   18.937833]  dump_stack+0x18/0x24 >>>> [   18.941166]  __vb2_queue_cancel+0x23c/0x2f0 >>>> [   18.945365]  vb2_core_queue_release+0x24/0x6c >>>> [   18.949740]  vb2_queue_release+0x10/0x1c >>>> [   18.953677]  v4l2_m2m_ctx_release+0x20/0x40 >>>> [   18.957892]  hantro_release+0x20/0x54 >>>> [   18.961584]  v4l2_release+0x74/0xec >>>> [   18.965110]  __fput+0xb4/0x274 >>>> [   18.968205]  __fput_sync+0x50/0x5c >>>> [   18.971626]  __arm64_sys_close+0x38/0x7c >>>> [   18.975562]  invoke_syscall+0x48/0x114 >>>> [   18.979329]  el0_svc_common.constprop.0+0xc0/0xe0 >>>> [   18.984068]  do_el0_svc+0x1c/0x28 >>>> [   18.987402]  el0_svc+0x40/0xe8 >>>> [   18.990470]  el0t_64_sync_handler+0x100/0x12c >>>> [   18.994842]  el0t_64_sync+0x190/0x194 >>>> >>>> This happen at boot time when hantro driver is open and close without other actions. >>> Ah, now I see the problem. q->bufs and q->bufs_map are allocated in >>> vb2_core_create_bufs and vb2_core_reqbufs, but they should be allocated >>> in vb2_queue_init: that's the counterpart of vb2_core_queue_release. >>> >>> With that change you shouldn't have to check for q->bufs/bufs_map anymore. >> It is a better solution but even like this vb2_core_queue_release() is called >> at least 2 times on the same vivid queue and without testing q->bufs_bitmap >> makes kernel crash. > Do you have a stacktrace for that? Perhaps vb2_core_queue_release should check > for q->bufs/q->bufs_map and return if those are NULL. But it could also be a > bug that it is called twice, it just was never noticed because it was harmless > before. I have added some printk to log that when running test-media on vivid: [ 130.497426] vb2_core_queue_init queue cap-0000000050d195ab allocate q->bufs 00000000dc2c15ed and q->bufs_bitmap 000000008173fc5a ... [ 130.733967] vb2_core_queue_release queue cap-0000000050d195ab release q->bufs and q->bufs_bitmap [ 133.866345] vb2_get_buffer queue cap-0000000050d195ab q->bufs_bitmap is NULL [ 133.873454] CPU: 1 PID: 321 Comm: v4l2-ctl Not tainted 6.6.0-rc1+ #542 [ 133.879997] Hardware name: NXP i.MX8MQ EVK (DT) [ 133.884536] Call trace: [ 133.886988] dump_backtrace+0x94/0xec [ 133.890673] show_stack+0x18/0x24 [ 133.894002] dump_stack_lvl+0x48/0x60 [ 133.897681] dump_stack+0x18/0x24 [ 133.901009] __vb2_queue_cancel+0x250/0x31c [ 133.905209] vb2_core_queue_release+0x24/0x88 [ 133.909580] _vb2_fop_release+0xb0/0xbc [ 133.913428] vb2_fop_release+0x2c/0x58 [ 133.917187] vivid_fop_release+0x80/0x388 [vivid] [ 133.921948] v4l2_release+0x74/0xec [ 133.925452] __fput+0xb4/0x274 [ 133.928520] __fput_sync+0x50/0x5c [ 133.931934] __arm64_sys_close+0x38/0x7c [ 133.935868] invoke_syscall+0x48/0x114 [ 133.939630] el0_svc_common.constprop.0+0x40/0xe0 [ 133.944349] do_el0_svc+0x1c/0x28 [ 133.947677] el0_svc+0x40/0xe8 [ 133.950741] el0t_64_sync_handler+0x100/0x12c [ 133.955109] el0t_64_sync+0x190/0x194 and later I have a call to reqbufs on the same queue without call to vb2_core_queue_init before [ 58.696812] __vb2_queue_alloc queue cap- 0000000050d195abq->bufs_bitmap is NULL [ 58.704148] CPU: 1 PID: 319 Comm: v4l2-compliance Not tainted 6.6.0-rc1+ #544 [ 58.711291] Hardware name: NXP i.MX8MQ EVK (DT) [ 58.715826] Call trace: [ 58.718274] dump_backtrace+0x94/0xec [ 58.721951] show_stack+0x18/0x24 [ 58.725274] dump_stack_lvl+0x48/0x60 [ 58.728946] dump_stack+0x18/0x24 [ 58.732268] __vb2_queue_alloc+0x4a8/0x50c [ 58.736374] vb2_core_reqbufs+0x274/0x46c [ 58.740391] vb2_ioctl_reqbufs+0xb0/0xe8 [ 58.744320] vidioc_reqbufs+0x50/0x64 [vivid] [ 58.748717] v4l_reqbufs+0x50/0x64 [ 58.752125] __video_do_ioctl+0x164/0x3c8 [ 58.756140] video_usercopy+0x200/0x668 [ 58.759982] video_ioctl2+0x18/0x28 [ 58.763475] v4l2_ioctl+0x40/0x60 [ 58.766798] __arm64_sys_ioctl+0xac/0xf0 [ 58.770730] invoke_syscall+0x48/0x114 [ 58.774487] el0_svc_common.constprop.0+0x40/0xe0 [ 58.779199] do_el0_svc+0x1c/0x28 [ 58.782520] el0_svc+0x40/0xe8 [ 58.785580] el0t_64_sync_handler+0x100/0x12c [ 58.789942] el0t_64_sync+0x190/0x194 > > Regards, > > Hans > >>> Regards, >>> >>>     Hans >>> >>>> >>>>>>>> + >>>>>>>> +    return (bitmap_weight(q->bufs_map, q->max_allowed_buffers) > 0); >>>>>>> How about: >>>>>>> >>>>>>>       return vb2_get_num_buffers(q) > 0; >>>>>> vb2_get_num_buffers is defined in videobuf2-core.c, I'm not sure that >>>>>> an inline function could depend of a module function. >>>>> Not a problem. E.g. v4l2-ctrls.h is full of such static inlines. >>>>> >>>>> Regards, >>>>> >>>>>      Hans >>>>> >