From nobody Fri May 29 15:20:40 2026 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4gRn9h5Zc3z6fhMT for ; Fri, 29 May 2026 15:20:40 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R13" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4gRn9h3744z4407 for ; Fri, 29 May 2026 15:20:40 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1780068040; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ccc+DiW6Trga8fiaWeU2HsVlAuRp+wbXP3RAwYyq7j8=; b=LCXm2jWXEchB435Mw7ivqRitihMPb9XRPejQAXPPpQOc8JEYGK+ibGbbHNTn/1RWEdh1rr /j078CdcAPdaBUxSigc2fL51SqmafymX2W5COIco3VnAKo4icFnheD042n6tS179zS9q9r A9GtF92h2pQRCkGTRjjN6hHFuiKg0Vh04kjMbYTT7D2I4mNS5RWwv4RdFAGMF93IuGx6SL b/3NM+OzCbYW5SaFKZpVxkXv5LU29o8jDRVWtzGNGdTWXIkO37damQ4hINS22/QpvYi8r9 6xYlOMXG0OTaIYdhH4dGWpRmWqn3EEvCIIYPJg4QNYNFahq2st1/2IHhslo1yQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1780068040; a=rsa-sha256; cv=none; b=WUkPLSLlCIF5FGLC0svJudDcToMAPBn7ms78AG2ja9RfgKmKSOXbZBYRgowOgVSzeGtR3q FWQH+DFaH46YX6DB6FPbCFyGe+IXmIPlsZxYuKUflhlr44qAE88sGvN+Dhc90sGGyPCkHE RolhouhZeWnt7TgUkLtRqzUY/bVDSjCAUsHN6EWYBhZvNIxKwwTCVPNZyCJkfWbTSsh/St kFYCVa7Zk/5xawCvAg3pDHVcwpcm4jhlKi04HNzJ9N1IsZ+Ai3AZ+/t1VoZnWVd8c/oHyK jBxXblmHBpVpnv4CpmgweH111PO4yi04jUQvIPbgHKJMOW6skvr5Nh0QJ2YJFw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1780068040; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ccc+DiW6Trga8fiaWeU2HsVlAuRp+wbXP3RAwYyq7j8=; b=qk5xJbvOwmzBGPB8P+d7lQtMNVQ3KobjZhA0Bp9qy07eMpC+8P5pryTChIOrqyWUCZn1tg xlD9ODthPdYKuv3MYHbNbwBzEthuEYbsmmcqGGoEwbXm2AF6IQL5Dl2OB7gxBuipas0eQw +1khHym1C0fRBu/T3OVFTAARDobX4wGpxB4BOkqHE+EM34zGXt+Fouy/gHIiEQv6sR1rC/ pFFgap7kEVpuFHW6wZddOTYfqTdciTENxnblk3glmN6YUbp9G3A163hCFRMOVllcWkYsMF Q9YcPlSSa5VgAUshsD/xMeb8Ta5VTnW+CUrpAm8d5BvAj3S3rL4bl4PaMD4Uwg== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4gRn9h23tPzdkQ for ; Fri, 29 May 2026 15:20:40 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 30fa0 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Fri, 29 May 2026 15:20:40 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: ShengYi Hung Subject: git: 83cddc84693a - stable/15 - sound: Fix lock order reversal in dsp_poll() List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: aokblast X-Git-Repository: src X-Git-Refname: refs/heads/stable/15 X-Git-Reftype: branch X-Git-Commit: 83cddc84693af1fb7f1ba6ee1213f2b9694eee3c Auto-Submitted: auto-generated Date: Fri, 29 May 2026 15:20:40 +0000 Message-Id: <6a19aec8.30fa0.506fdd3a@gitrepo.freebsd.org> The branch stable/15 has been updated by aokblast: URL: https://cgit.FreeBSD.org/src/commit/?id=83cddc84693af1fb7f1ba6ee1213f2b9694eee3c commit 83cddc84693af1fb7f1ba6ee1213f2b9694eee3c Author: ShengYi Hung AuthorDate: 2026-05-15 08:43:47 +0000 Commit: ShengYi Hung CommitDate: 2026-05-29 15:19:49 +0000 sound: Fix lock order reversal in dsp_poll() chn_poll() may hold both rdch and wrch channel locks while calling chn_trigger(rdch). chn_trigger() switches the lock order from "channel -> dsp dev" to "dsp dev -> channel" by temporarily dropping the channel lock before acquiring the dsp lock. However, only rdch was unlocked during the transition while wrch remained locked. Since wrch is also a channel lock and witness had already established the lock order requirement: dsp dev -> channel witness reports a lock order reversal when pcm_lock() is acquired while wrch is still held. Avoid holding rdch and wrch simultaneously during chn_trigger() lock-order switching by only keeping the channel locks when needed. The issue can be reliably reproduced by starting pipewire, pipewire-pulse, and pavucontrol. Reviewed by: christos MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D57009 (cherry picked from commit 776584319fb4d66cdb1c2f91bed154dfe6a74e5e) --- sys/dev/sound/pcm/dsp.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c index 6d76877e90ba..82c960fc3b40 100644 --- a/sys/dev/sound/pcm/dsp.c +++ b/sys/dev/sound/pcm/dsp.c @@ -1877,24 +1877,25 @@ dsp_poll(struct cdev *i_dev, int events, struct thread *td) ret = 0; - dsp_lock_chans(priv, FREAD | FWRITE); wrch = priv->wrch; rdch = priv->rdch; if (wrch != NULL && !(wrch->flags & CHN_F_DEAD)) { + CHN_LOCK(wrch); e = (events & (POLLOUT | POLLWRNORM)); if (e) ret |= chn_poll(wrch, e, td); + CHN_UNLOCK(wrch); } if (rdch != NULL && !(rdch->flags & CHN_F_DEAD)) { + CHN_LOCK(rdch); e = (events & (POLLIN | POLLRDNORM)); if (e) ret |= chn_poll(rdch, e, td); + CHN_UNLOCK(rdch); } - dsp_unlock_chans(priv, FREAD | FWRITE); - PCM_GIANT_LEAVE(d); return (ret);