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 X-Spam-Level: X-Spam-Status: No, score=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2CE5C47E49 for ; Mon, 4 Nov 2019 08:02:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D376E21D7D for ; Mon, 4 Nov 2019 08:02:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727320AbfKDICp (ORCPT ); Mon, 4 Nov 2019 03:02:45 -0500 Received: from mx2.suse.de ([195.135.220.15]:39418 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727138AbfKDICp (ORCPT ); Mon, 4 Nov 2019 03:02:45 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 80E71AD0B; Mon, 4 Nov 2019 08:02:42 +0000 (UTC) Date: Mon, 04 Nov 2019 09:02:41 +0100 Message-ID: From: Takashi Iwai To: youling 257 Cc: linux-xtensa@linux-xtensa.org, Michal Simek , Vladimir Murzin , linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, Takashi Iwai , linuxppc-dev@lists.ozlabs.org, Helge Deller , x86@kernel.org, Linux Kernel Mailing List , linux-m68k@lists.linux-m68k.org, Robin Murphy , linux-arm-kernel@lists.infradead.org, hch@lst.de, gregkh@google.com Subject: Re: ALSA: pcm: use dma_can_mmap() to check if a device supports dma_mmap_* In-Reply-To: References: User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On Mon, 04 Nov 2019 08:06:37 +0100, youling 257 wrote: > > This patch cause oops on android mainline kernel about gadget audio_source. > Androidx86 run on android mainline kernel. > > [ 385.104963] android_work: sent uevent USB_STATE=CONNECTED > [ 385.109006] android_work: sent uevent USB_STATE=DISCONNECTED > [ 385.182024] android_work: sent uevent USB_STATE=CONNECTED > [ 385.184737] configfs-gadget gadget: high-speed config #1: b > [ 385.184921] android_work: sent uevent USB_STATE=CONFIGURED > [ 385.285268] BUG: kernel NULL pointer dereference, address: 0000000000000220 > [ 385.285339] #PF: supervisor read access in kernel mode > [ 385.285374] #PF: error_code(0x0000) - not-present page > [ 385.285436] PGD 80000000791e6067 P4D 80000000791e6067 PUD 0 > [ 385.285473] Oops: 0000 [#1] PREEMPT SMP PTI > [ 385.285509] CPU: 0 PID: 5780 Comm: Binder:1383_5 Tainted: G O > 5.4.0-rc6-android-x86_64+ #1 > [ 385.285571] Hardware name: Insyde ONDA Tablet/ONDA Tablet, BIOS > ONDA.D890HBBNR0A 03/11/2015 > [ 385.285639] RIP: 0010:dma_can_mmap+0x5/0x30 > [ 385.285675] Code: 74 11 e9 ae 98 b2 00 48 8b 05 9f 40 94 01 48 85 c0 > 75 e3 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 > 00 00 <48> 8b 87 20 02 00 00 48 85 c0 74 09 48 83 78 10 00 0f 95 c0 c3 > 48 > [ 385.285762] RSP: 0018:ffffb39443b63b78 EFLAGS: 00010246 > [ 385.285797] RAX: 0000000000000001 RBX: ffffa28b91756600 RCX: 0000000000000040 > [ 385.285857] RDX: ffffffffb62b2a00 RSI: 0000000000000000 RDI: 0000000000000000 > [ 385.285917] RBP: ffffa28bac69f800 R08: ffffffffb63141b0 R09: ffffa28bf9a34a88 > [ 385.285952] R10: ffffffffb62b2be0 R11: ffffffffb62b2bd0 R12: 0000000000000008 > [ 385.286013] R13: 0000000000000000 R14: ffffa28bacd736a8 R15: ffffa28bacd736c8 > [ 385.286076] FS: 0000000000000000(0000) GS:ffffa28bfb600000(0063) > knlGS:00000000f5d81970 > [ 385.286110] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > [ 385.286171] CR2: 0000000000000220 CR3: 000000007b2f6000 CR4: 00000000001006f0 > [ 385.286232] Call Trace: > [ 385.286275] snd_pcm_hw_constraints_complete+0x3e/0x1f0 > [ 385.286314] snd_pcm_open_substream+0x94/0x140 > [ 385.286377] snd_pcm_open+0xf0/0x240 > [ 385.286416] ? wake_up_q+0x60/0x60 > [ 385.286460] snd_pcm_playback_open+0x3d/0x60 > [ 385.286533] chrdev_open+0xa2/0x1c0 > [ 385.286574] ? cdev_put.part.0+0x20/0x20 > [ 385.286615] do_dentry_open+0x13a/0x380 > [ 385.286686] path_openat+0x588/0x15d0 > [ 385.286728] do_filp_open+0x91/0x100 > [ 385.286769] ? __check_object_size+0x136/0x147 > [ 385.286840] do_sys_open+0x184/0x280 > [ 385.286880] ? handle_mm_fault+0xd7/0x1c0 > [ 385.286920] do_fast_syscall_32+0x8e/0x250 > [ 385.286992] entry_SYSENTER_compat+0x7c/0x8e > > [ 385.287302] CR2: 0000000000000220 > [ 385.287391] ---[ end trace 73ffcefcbbe2b9a0 ]--- Exactly which driver is hit? The code path is via hw_support_mmap() and it's currently: static bool hw_support_mmap(struct snd_pcm_substream *substream) { if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_MMAP)) return false; if (substream->ops->mmap || substream->dma_buffer.dev.type != SNDRV_DMA_TYPE_DEV) return true; return dma_can_mmap(substream->dma_buffer.dev.dev); } so at least the driver has already set the SNDRV_DMA_TYPE_DEV explicitly (it's non-zero) and some device object, but the device object was invalid for dma_can_mmap() call. This smells more like a driver-side issue, not in the core side. thanks, Takashi