From patchwork Sun Nov 5 17:25:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Volker_R=C3=BCmelin?= X-Patchwork-Id: 13446042 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8D2B6C4332F for ; Sun, 5 Nov 2023 17:26:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qzgt0-0001OO-NP; Sun, 05 Nov 2023 12:26:10 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qzgsy-0001OC-UH for qemu-devel@nongnu.org; Sun, 05 Nov 2023 12:26:08 -0500 Received: from mailout06.t-online.de ([194.25.134.19]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qzgsw-0006va-QB for qemu-devel@nongnu.org; Sun, 05 Nov 2023 12:26:08 -0500 Received: from fwd70.aul.t-online.de (fwd70.aul.t-online.de [10.223.144.96]) by mailout06.t-online.de (Postfix) with SMTP id 611F84973; Sun, 5 Nov 2023 18:26:02 +0100 (CET) Received: from linpower.localnet ([93.236.156.187]) by fwd70.t-online.de with (TLSv1.3:TLS_AES_256_GCM_SHA384 encrypted) esmtp id 1qzgsj-0PFCNd0; Sun, 5 Nov 2023 18:25:53 +0100 Received: by linpower.localnet (Postfix, from userid 1000) id BEFFC2002D8; Sun, 5 Nov 2023 18:25:52 +0100 (CET) From: =?utf-8?q?Volker_R=C3=BCmelin?= To: Gerd Hoffmann Cc: =?utf-8?q?Marc-Andr=C3=A9_Lureau?= , Paolo Bonzini , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, M_O_Bz , linwei6@ruijie.com.cn Subject: [PATCH 1/2] hw/audio/hda-codec: fix multiplication overflow Date: Sun, 5 Nov 2023 18:25:51 +0100 Message-Id: <20231105172552.8405-1-vr_qemu@t-online.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <6f8b1f96-4520-49d5-8a09-b2935ab4bd9d@t-online.de> References: <6f8b1f96-4520-49d5-8a09-b2935ab4bd9d@t-online.de> MIME-Version: 1.0 X-TOI-EXPURGATEID: 150726::1699205153-F894633D-2A38B07D/0/0 CLEAN NORMAL X-TOI-MSGID: 4b476fa0-738d-419c-8907-c4eb5fe76348 Received-SPF: pass client-ip=194.25.134.19; envelope-from=volker.ruemelin@t-online.de; helo=mailout06.t-online.de X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org After a relatively short time, there is an multiplication overflow when multiplying (now - buft_start) with hda_bytes_per_second(). While the uptime now - buft_start only overflows after 2**63 ns = 292.27 years, this happens hda_bytes_per_second() times faster with the multiplication. At 44100 samples/s * 2 channels * 2 bytes/channel = 176400 bytes/s that is 14.52 hours. After the multiplication overflow the affected audio stream stalls. Replace the multiplication and following division with muldiv64() to prevent a multiplication overflow. Fixes: 280c1e1cdb ("audio/hda: create millisecond timers that handle IO") Reported-by: M_O_Bz Signed-off-by: Volker Rümelin Reviewed-by: Marc-André Lureau --- hw/audio/hda-codec.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/hw/audio/hda-codec.c b/hw/audio/hda-codec.c index b9ad1f4c39..f756e419bb 100644 --- a/hw/audio/hda-codec.c +++ b/hw/audio/hda-codec.c @@ -22,6 +22,7 @@ #include "hw/qdev-properties.h" #include "intel-hda.h" #include "migration/vmstate.h" +#include "qemu/host-utils.h" #include "qemu/module.h" #include "intel-hda-defs.h" #include "audio/audio.h" @@ -189,9 +190,9 @@ struct HDAAudioState { bool use_timer; }; -static inline int64_t hda_bytes_per_second(HDAAudioStream *st) +static inline uint32_t hda_bytes_per_second(HDAAudioStream *st) { - return 2LL * st->as.nchannels * st->as.freq; + return 2 * (uint32_t)st->as.nchannels * (uint32_t)st->as.freq; } static inline void hda_timer_sync_adjust(HDAAudioStream *st, int64_t target_pos) @@ -222,12 +223,18 @@ static void hda_audio_input_timer(void *opaque) int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - int64_t buft_start = st->buft_start; + int64_t uptime = now - st->buft_start; int64_t wpos = st->wpos; int64_t rpos = st->rpos; + int64_t wanted_rpos; - int64_t wanted_rpos = hda_bytes_per_second(st) * (now - buft_start) - / NANOSECONDS_PER_SECOND; + if (uptime <= 0) { + /* wanted_rpos <= 0 */ + goto out_timer; + } + + wanted_rpos = muldiv64(uptime, hda_bytes_per_second(st), + NANOSECONDS_PER_SECOND); wanted_rpos &= -4; /* IMPORTANT! clip to frames */ if (wanted_rpos <= rpos) { @@ -286,12 +293,18 @@ static void hda_audio_output_timer(void *opaque) int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - int64_t buft_start = st->buft_start; + int64_t uptime = now - st->buft_start; int64_t wpos = st->wpos; int64_t rpos = st->rpos; + int64_t wanted_wpos; + + if (uptime <= 0) { + /* wanted_wpos <= 0 */ + goto out_timer; + } - int64_t wanted_wpos = hda_bytes_per_second(st) * (now - buft_start) - / NANOSECONDS_PER_SECOND; + wanted_wpos = muldiv64(uptime, hda_bytes_per_second(st), + NANOSECONDS_PER_SECOND); wanted_wpos &= -4; /* IMPORTANT! clip to frames */ if (wanted_wpos <= wpos) {