From patchwork Wed Jun 20 14:39:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 10477657 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9B4F460230 for ; Wed, 20 Jun 2018 14:39:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5353428EB5 for ; Wed, 20 Jun 2018 14:39:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 45E7A28ED6; Wed, 20 Jun 2018 14:39:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6D09628EB5 for ; Wed, 20 Jun 2018 14:39:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753960AbeFTOj2 (ORCPT ); Wed, 20 Jun 2018 10:39:28 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:60566 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753906AbeFTOj1 (ORCPT ); Wed, 20 Jun 2018 10:39:27 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1fVeGY-00072h-TL; Wed, 20 Jun 2018 16:39:23 +0200 Date: Wed, 20 Jun 2018 16:39:22 +0200 From: Sebastian Andrzej Siewior To: Takashi Iwai Cc: alsa-devel@alsa-project.org, tglx@linutronix.de, Jaroslav Kysela , linux-usb@vger.kernel.org Subject: Re: [PATCH 8/9] ALSA: usx2y: usbusx2yaudio: use usb_fill_int_urb() Message-ID: <20180620143922.nkcazvbcrmkyvm2c@linutronix.de> References: <20180619215521.13688-1-bigeasy@linutronix.de> <20180619215521.13688-9-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180512 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On 2018-06-20 14:51:12 [+0200], Takashi Iwai wrote: > On Tue, 19 Jun 2018 23:55:20 +0200, > Sebastian Andrzej Siewior wrote: > > - (*purb)->transfer_buffer = > > - kmalloc_array(subs->maxpacksize, > > - nr_of_packs(), GFP_KERNEL); > > - if (NULL == (*purb)->transfer_buffer) { > > + len = subs->maxpacksize * nr_of_packs(); > > + buf = kmalloc(len, GFP_KERNEL); > > I'd keep kmalloc_array() as is, and just put subs->maxpacksize * > nr_of_packs() in usb_fill_int_urb(). Otherwise it's a step backward. but then we end up with two multiplications. What about pulling the overflow-mul macro out of malloc_array() and doing this instead: ----------- >8 Subject: [PATCH 8/9 v2] ALSA: usx2y: usbusx2yaudio: use usb_fill_int_urb() Using usb_fill_int_urb() helps to find code which initializes an URB. A grep for members of the struct (like ->complete) reveal lots of other things, too. The "&& !(*purb)->transfer_buffer" check has been removed because the URB has been freshly allocated a few lines above so ->transfer_buffer has to be NULL here. The `dev' and `transfer_size' assignments have been moved from usX2Y_urbs_start() to usX2Y_urbs_allocate() because they don't change overtime. The multiplication via check_mul_overflow() has been extracted from kmalloc_array() to avoid two multiplication (one with overflow check and one without for the length argument). This requires to change the type `maxpacksize' to int so there is only one type involved in the multiplication. Cc: Jaroslav Kysela Cc: Takashi Iwai Signed-off-by: Sebastian Andrzej Siewior --- sound/usb/usx2y/usbusx2y.h | 2 +- sound/usb/usx2y/usbusx2yaudio.c | 38 ++++++++++++++++----------------- 2 files changed, 20 insertions(+), 20 deletions(-) diff --git a/sound/usb/usx2y/usbusx2y.h b/sound/usb/usx2y/usbusx2y.h index e0f77172ce8f..2bec412589b4 100644 --- a/sound/usb/usx2y/usbusx2y.h +++ b/sound/usb/usx2y/usbusx2y.h @@ -56,7 +56,7 @@ struct snd_usX2Y_substream { struct snd_pcm_substream *pcm_substream; int endpoint; - unsigned int maxpacksize; /* max packet size in bytes */ + int maxpacksize; /* max packet size in bytes */ atomic_t state; #define state_STOPPED 0 diff --git a/sound/usb/usx2y/usbusx2yaudio.c b/sound/usb/usx2y/usbusx2yaudio.c index 2b833054e3b0..e5580cb59858 100644 --- a/sound/usb/usx2y/usbusx2yaudio.c +++ b/sound/usb/usx2y/usbusx2yaudio.c @@ -425,33 +425,35 @@ static int usX2Y_urbs_allocate(struct snd_usX2Y_substream *subs) /* allocate and initialize data urbs */ for (i = 0; i < NRURBS; i++) { struct urb **purb = subs->urb + i; + void *buf = NULL; + int len = 0; + if (*purb) { usb_kill_urb(*purb); continue; } *purb = usb_alloc_urb(nr_of_packs(), GFP_KERNEL); - if (NULL == *purb) { - usX2Y_urbs_release(subs); - return -ENOMEM; - } - if (!is_playback && !(*purb)->transfer_buffer) { + if (NULL == *purb) + goto err_free; + + if (!is_playback) { /* allocate a capture buffer per urb */ - (*purb)->transfer_buffer = - kmalloc_array(subs->maxpacksize, - nr_of_packs(), GFP_KERNEL); - if (NULL == (*purb)->transfer_buffer) { - usX2Y_urbs_release(subs); - return -ENOMEM; - } + if (check_mul_overflow(subs->maxpacksize, + nr_of_packs(), + &len)) + goto err_free; + buf = kmalloc(len, GFP_KERNEL); + if (!buf) + goto err_free; } - (*purb)->dev = dev; - (*purb)->pipe = pipe; + usb_fill_int_urb(*purb, dev, pipe, buf, len, + i_usX2Y_subs_startup, subs, 1); (*purb)->number_of_packets = nr_of_packs(); - (*purb)->context = subs; - (*purb)->interval = 1; - (*purb)->complete = i_usX2Y_subs_startup; } return 0; +err_free: + usX2Y_urbs_release(subs); + return -ENOMEM; } static void usX2Y_subs_startup(struct snd_usX2Y_substream *subs) @@ -485,12 +487,10 @@ static int usX2Y_urbs_start(struct snd_usX2Y_substream *subs) unsigned long pack; if (0 == i) atomic_set(&subs->state, state_STARTING3); - urb->dev = usX2Y->dev; for (pack = 0; pack < nr_of_packs(); pack++) { urb->iso_frame_desc[pack].offset = subs->maxpacksize * pack; urb->iso_frame_desc[pack].length = subs->maxpacksize; } - urb->transfer_buffer_length = subs->maxpacksize * nr_of_packs(); if ((err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) { snd_printk (KERN_ERR "cannot submit datapipe for urb %d, err = %d\n", i, err); err = -EPIPE;