From nobody Tue Nov 25 14:02:12 2025 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 4dG4BX4YMnz6JBqm for ; Tue, 25 Nov 2025 14:02:12 +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 "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4dG4BX3fwsz3NFj for ; Tue, 25 Nov 2025 14:02:12 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1764079332; 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=1cxLiYDuSmhXfYN4K0RLCPjuw+1sLfH3SpzK4lZz7aU=; b=TbNoiJX8z6IuSI7zHnJut2Pd3qkHpz076X5nngHKvPNuVQhvAZnHwSecofL/l7zTT4E/3x m32upi1lfNYbXwJVxgxdv+olaeThCnurlB+Majk9lpldWfS0Hhcy6OEAw2l86xOeFGdXE1 FlZnqEIO/+VWvPKNkvOhF4+YASZFUn9/yGk0OX/P9GwZzD5ME0WbnM/Fak2v0iFMtAQEU+ wO57uZHOxFb10354XkhWPSxtWSg30k8cADWZzAPv7IQckKsG28Avq+RGzcJnJElUH1Rpn7 J2JD3+IkN+sgsYUhvCULs0JVa5eYwJaUPIW+CFSP0gILKubUWMf9JCc04xjMUA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1764079332; 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=1cxLiYDuSmhXfYN4K0RLCPjuw+1sLfH3SpzK4lZz7aU=; b=GzjDza+uXWHr/I+C2N+FD42f58Ja81MGNl2QKt53WwCszVlqWeA3JxlYmqy5sBhncKWgY5 jEPbwgLrtyUIqh7KYrgwhN2/mbQMqtPg/ApxbzUMzla4CWFtRu4g3M14iWao11ckc91tWr GQvlbZ3HgbZblhN/K6JEPb38RkaAz5pzAPHa+mV4aXJOUa7/gwakHSo3fSTMa80ygSv/qg pXcXJ8SxtztY7iDlCS5Ed2CMfEzVNekdMjxOS5mXnC3pT/OB827xUK+gEn11VQCiy0CTHf vGoG9vUTt5dyic+mPGHuD6NlFk1bQBcgdy3HBfq7pBB6LAqtsyT0DLFGiW+oGA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1764079332; a=rsa-sha256; cv=none; b=J5LsML5D60LsD7Y96e6soP19ELy7F/ZNgpgoR1WQc//RMEJ1dnEZR+jhy0zZSI7SKHRo1x CVa8uS4pqGeCEbkwSDUnw2XKddIDpEJdhZOukNg/7tvFTbO71kovX5l8P/+bX+DPhKQcsY pJbT0EZQhi9Ku4vH3dnhQ4O+vRn7asefhwKiKTEOtMhgiDR/xj88MGHp0Cbtjqullk46lU sHAh+VQA6AIKsxUUgHeqEyQbTifxu/VZyIj+XVyu8jA1Z2uDdx5zCk+/ImZX+XZqvyJZnl G6lNPzsuX5JAByS7NiYgbh3GbMC7R49k47QOu1b/kQkIaKHLFCT+2PZX0wCFDw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4dG4BX3C2Bz138N for ; Tue, 25 Nov 2025 14:02:12 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 2d140 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 25 Nov 2025 14:02:12 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: f8bf6f81d6c2 - stable/14 - kevent: Hold the knlist mutex when invoking f_event(NOTE_FORK) 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 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/stable/14 X-Git-Reftype: branch X-Git-Commit: f8bf6f81d6c2b73b065befedddac3bf29f2963de Auto-Submitted: auto-generated Date: Tue, 25 Nov 2025 14:02:12 +0000 Message-Id: <6925b6e4.2d140.4f1a4e33@gitrepo.freebsd.org> The branch stable/14 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=f8bf6f81d6c2b73b065befedddac3bf29f2963de commit f8bf6f81d6c2b73b065befedddac3bf29f2963de Author: Mark Johnston AuthorDate: 2025-11-18 14:22:04 +0000 Commit: Mark Johnston CommitDate: 2025-11-25 13:57:14 +0000 kevent: Hold the knlist mutex when invoking f_event(NOTE_FORK) In general f_event is supposed to be called with the knlist mutex held, so lock it earlier to follow this protocol. Also make sure that the update to kn_fflags is synchronized. Lock the kqueue itself earlier in the case where the knote is activated, to avoid locking and unlocking the kqueue twice. PR: 291005 Reported by: Qiu-ji Chen Reviewed by: kib MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D53762 (cherry picked from commit d795c753e262b97a93dc353aa66b858e1b1969d1) --- sys/kern/kern_event.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c index d1145c37e128..4aba212544f7 100644 --- a/sys/kern/kern_event.c +++ b/sys/kern/kern_event.c @@ -603,12 +603,20 @@ knote_fork(struct knlist *list, int pid) kev.data = kn->kn_id; /* parent */ kev.udata = kn->kn_kevent.udata;/* preserve udata */ error = kqueue_register(kq, &kev, NULL, M_NOWAIT); + + /* + * Serialize updates to the kn_kevent fields with threads + * scanning the queue. + */ + list->kl_lock(list->kl_lockarg); if (error) kn->kn_fflags |= NOTE_TRACKERR; - if (kn->kn_fop->f_event(kn, NOTE_FORK)) - KNOTE_ACTIVATE(kn, 0); - list->kl_lock(list->kl_lockarg); - KQ_LOCK(kq); + if (kn->kn_fop->f_event(kn, NOTE_FORK)) { + KQ_LOCK(kq); + KNOTE_ACTIVATE(kn, 1); + } else { + KQ_LOCK(kq); + } kn_leave_flux(kn); KQ_UNLOCK_FLUX(kq); }