From patchwork Thu Jul 1 14:43:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 469391 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 442B5C11F67 for ; Thu, 1 Jul 2021 14:43:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 292C26141E for ; Thu, 1 Jul 2021 14:43:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232580AbhGAOpi (ORCPT ); Thu, 1 Jul 2021 10:45:38 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:34737 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231142AbhGAOpi (ORCPT ); Thu, 1 Jul 2021 10:45:38 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lyxuE-0001vL-5Z; Thu, 01 Jul 2021 14:43:06 +0000 From: Colin King To: Felipe Balbi , Greg Kroah-Hartman , linux-usb@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] usb: gadget: u_serial: remove WARN_ON on null port Date: Thu, 1 Jul 2021 15:43:05 +0100 Message-Id: <20210701144305.110078-1-colin.king@canonical.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Colin Ian King Loading and then unloading module g_dpgp on a VM that does not support the driver currently throws a WARN_ON message because the port has not been initialized. Removing an unused driver is a valid use-case and the WARN_ON kernel warning is a bit excessive, so remove it. Cleans up: [27654.638698] ------------[ cut here ]------------ [27654.638705] WARNING: CPU: 6 PID: 2956336 at drivers/usb/gadget/function/u_serial.c:1201 gserial_free_line+0x7c/0x90 [u_serial] [27654.638728] Modules linked in: g_dbgp(-) u_serial usb_f_tcm target_core_mod libcomposite udc_core vmw_vmci mcb i2c_nforce2 i2c_amd756 nfit cx8800 videobuf2_dma_sg videobuf2_memops videobuf2_v4l2 cx88xx tveeprom videobuf2_common videodev mc ccp hid_generic hid intel_ishtp cros_ec mc13xxx_core vfio_mdev mdev i915 i2c_algo_bit kvm ppdev parport zatm eni suni uPD98402 atm rio_scan binder_linux hwmon_vid video ipmi_devintf ipmi_msghandler zstd nls_utf8 decnet qrtr ns sctp ip6_udp_tunnel udp_tunnel fcrypt pcbc nhc_udp nhc_ipv6 nhc_routing nhc_mobility nhc_hop nhc_dest nhc_fragment 6lowpan ts_kmp dccp_ipv6 dccp_ipv4 dccp snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq_dummy snd_seq snd_seq_device xen_front_pgdir_shbuf binfmt_misc nls_iso8859_1 dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua intel_rapl_msr intel_rapl_common snd_hda_codec_generic ledtrig_audio snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd rapl soundcore joydev input_leds mac_hid serio_raw efi_pstore [27654.638880] qemu_fw_cfg sch_fq_codel msr virtio_rng autofs4 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear qxl drm_ttm_helper crct10dif_pclmul ttm drm_kms_helper syscopyarea sysfillrect sysimgblt virtio_net fb_sys_fops cec net_failover rc_core ahci psmouse drm libahci lpc_ich virtio_blk failover [last unloaded: u_ether] [27654.638949] CPU: 6 PID: 2956336 Comm: modprobe Tainted: P O 5.13.0-9-generic #9 [27654.638956] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [27654.638969] RIP: 0010:gserial_free_line+0x7c/0x90 [u_serial] [27654.638981] Code: 20 00 00 00 00 e8 74 1a ba c9 4c 89 e7 e8 8c fe ff ff 48 8b 3d 75 3b 00 00 44 89 f6 e8 3d 7c 69 c9 5b 41 5c 41 5d 41 5e 5d c3 <0f> 0b 4c 89 ef e8 4a 1a ba c9 5b 41 5c 41 5d 41 5e 5d c3 90 0f 1f [27654.638986] RSP: 0018:ffffba0b81403da0 EFLAGS: 00010246 [27654.638992] RAX: 0000000000000000 RBX: ffffffffc0eaf6a0 RCX: 0000000000000000 [27654.638996] RDX: ffff8e21c0cac8c0 RSI: 0000000000000006 RDI: ffffffffc0eaf6a0 [27654.639000] RBP: ffffba0b81403dc0 R08: ffffba0b81403de0 R09: fefefefefefefeff [27654.639003] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [27654.639006] R13: ffffffffc0eaf6a0 R14: 0000000000000000 R15: 0000000000000000 [27654.639010] FS: 00007faa1935e740(0000) GS:ffff8e223bd80000(0000) knlGS:0000000000000000 [27654.639015] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [27654.639019] CR2: 00007ffc840cd4e8 CR3: 000000000e1ac006 CR4: 0000000000370ee0 [27654.639028] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [27654.639031] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [27654.639035] Call Trace: [27654.639044] dbgp_exit+0x1c/0xa1a [g_dbgp] [27654.639054] __do_sys_delete_module.constprop.0+0x144/0x260 [27654.639066] ? call_rcu+0xe/0x10 [27654.639073] __x64_sys_delete_module+0x12/0x20 [27654.639081] do_syscall_64+0x61/0xb0 [27654.639092] ? exit_to_user_mode_loop+0xec/0x160 [27654.639098] ? exit_to_user_mode_prepare+0x37/0xb0 [27654.639104] ? syscall_exit_to_user_mode+0x27/0x50 [27654.639110] ? __x64_sys_close+0x12/0x40 [27654.639119] ? do_syscall_64+0x6e/0xb0 [27654.639126] ? exit_to_user_mode_prepare+0x37/0xb0 [27654.639132] ? syscall_exit_to_user_mode+0x27/0x50 [27654.639137] ? __x64_sys_newfstatat+0x1e/0x20 [27654.639146] ? do_syscall_64+0x6e/0xb0 [27654.639154] ? exc_page_fault+0x8f/0x170 [27654.639159] ? asm_exc_page_fault+0x8/0x30 [27654.639166] entry_SYSCALL_64_after_hwframe+0x44/0xae [27654.639173] RIP: 0033:0x7faa194a4b2b [27654.639179] Code: 73 01 c3 48 8b 0d 3d 73 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 0d 73 0c 00 f7 d8 64 89 01 48 [27654.639185] RSP: 002b:00007ffc840d0578 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 [27654.639191] RAX: ffffffffffffffda RBX: 000056060f9f4e70 RCX: 00007faa194a4b2b [27654.639194] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000056060f9f4ed8 [27654.639197] RBP: 000056060f9f4e70 R08: 0000000000000000 R09: 0000000000000000 [27654.639200] R10: 00007faa1951eac0 R11: 0000000000000206 R12: 000056060f9f4ed8 [27654.639203] R13: 0000000000000000 R14: 000056060f9f4ed8 R15: 00007ffc840d06c8 [27654.639219] ---[ end trace 8dd0ea0bb32ce94a ]--- Signed-off-by: Colin Ian King --- drivers/usb/gadget/function/u_serial.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c index 1e59204..83fb82c 100644 --- a/drivers/usb/gadget/function/u_serial.c +++ b/drivers/usb/gadget/function/u_serial.c @@ -1198,7 +1198,7 @@ void gserial_free_line(unsigned char port_num) struct gs_port *port; mutex_lock(&ports[port_num].lock); - if (WARN_ON(!ports[port_num].port)) { + if (!ports[port_num].port) { mutex_unlock(&ports[port_num].lock); return; }