From nobody Tue Nov 25 14:02:28 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 4dG4Br4fWmz6JBqq for ; Tue, 25 Nov 2025 14:02:28 +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 4dG4Br3Nnqz3NdJ for ; Tue, 25 Nov 2025 14:02:28 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1764079348; 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=14liq3eF8ump4gsjnQtdrWuvftj5cvnAE6cxwciJu5A=; b=uKe61f6RLTV1YsKljWYsVCBaB6LZi2m5O8Z9FV8AXwd+452dj13oyASvuNW5JGxzC8lJ+f /xDJcubzDs0avzp42MBqdqocd0D0K6w4WTQ61HB6l2SRKRGxq+WoPI4I4dpFpnpfwclTPk uQIN5w+kLawujJjXBYoyZFS3Z3H7495fZJOx5WSy5Fg0eSKLXP09KFS+ALcpPn/F+727TK Q+yr5++xeBqtlj9oYb7GlK38zWwBYYwY8TUEFy+A05Pz7dCBp2gpRSMrtQSh0Kt2wmDVM5 2G0U7AJFLp4kO36MWe3A0w4nBAJZ3CngVdVQzGErr2HkBeICtJEJ1UxgqyJKdA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1764079348; 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=14liq3eF8ump4gsjnQtdrWuvftj5cvnAE6cxwciJu5A=; b=uAGAYCB0m8FrkHxbWS02fZ2k33bY7Q8z7hEf00Omw4zxtbgPqbsVy3DIZewApNzVI5vnP9 H7sL9N3OthSe1nMzgKCH8XKttDgpIJUM78g0eQ2fNsPgVpP/P+TBiFu1YFgWlOpD44P3Qr nJh8OVFQzNxTcqv78zMPkKG+XVSsXqDDEkIFvrjWxSMWm/yQWe128kU05/8+tD5t63vOMi 45qrDS4KvWevfeLuu4rToRUkbsQ15sRsCPaf3SMsgGYgus0WAVQ5bFMqUDfZL6YwKTRd3i u8IbnjA05/hb1km4/w4cOl0efeLoYfuUg7uMo7aqJyvTUsIXP/m68PUk60ffFQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1764079348; a=rsa-sha256; cv=none; b=gXQRsDZMS058Y7BeX6/IYTD3X1J+l0WDv4545LYuJmECUABbmQdoNI3CZFfy3SjxTPqdZU HrY3E1Y8pfWwDaI58YMoZlQxxJ/QzcOKMQ7jxTdBVk8AzQASTkgr0afJTNkNsnSjlQFp+0 5KrEzNOMbL/E4Y+zHFCNSwyMqGn10DUm1thOmWcOSLN04oDCt9EE/a+clTwyMv+G6yxmCJ HqHuLfyYJInSq5wl07c5UJhdLV8O98kbofbSOQOHouOySgZrf+51Luru0jVeA2LdOBP67v 85Lms3RSHg/AfTa6e1I/P3dyRkZEGImtN5L4X/Dpt/Ig1jEG82pWr7TnL6KlPA== 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 4dG4Br2xwwz13vn for ; Tue, 25 Nov 2025 14:02:28 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 2da45 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 25 Nov 2025 14:02:28 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: 23ddcd227ab7 - stable/15 - 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/15 X-Git-Reftype: branch X-Git-Commit: 23ddcd227ab71b1d687f9ea298696f7d082c9cd5 Auto-Submitted: auto-generated Date: Tue, 25 Nov 2025 14:02:28 +0000 Message-Id: <6925b6f4.2da45.303f61bd@gitrepo.freebsd.org> The branch stable/15 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=23ddcd227ab71b1d687f9ea298696f7d082c9cd5 commit 23ddcd227ab71b1d687f9ea298696f7d082c9cd5 Author: Mark Johnston AuthorDate: 2025-11-18 14:22:04 +0000 Commit: Mark Johnston CommitDate: 2025-11-25 14:02:20 +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 84af7b264d08..c18bf3b12352 100644 --- a/sys/kern/kern_event.c +++ b/sys/kern/kern_event.c @@ -627,12 +627,20 @@ 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); }