From nobody Tue Nov 18 16:24:47 2025 X-Original-To: dev-commits-src-main@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 4d9qhH4z1Lz6HNnw for ; Tue, 18 Nov 2025 16:24:47 +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 4d9qhH2c6Yz4JX6 for ; Tue, 18 Nov 2025 16:24:47 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1763483087; 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=Llrc7nT3cZqRcsR9CJkYvm5PhXqkejZRpjAZVy1MxeE=; b=ifX6gB85E7UdmjY4DmqUUmwsMUsqkJVLjhy94LHQLjnGsDgDTeATA8oZzvxs+ql7XgcrPh WhbLEeub4ELIgLnXUVABBAY+uZP6oiq1j/M+DoI9mLkB+IZuX6nK13GoD1D3hdpCFdTrko qyNWp2ftiW2kXpea/NLFXgP9T1CCuC1/ohMZoDVjmWI1C8B+xX4kAztd7h7T82BwJnM7u4 yX+530vEdzfbUiEEcb9dyhItp0w/POa0s5TGTeIq66EjdGAXhUfAhoZZ+mTCwRkUpxAqq8 D5R4/+GkH0TMkxgqQD+EBYjJU8jPPKgLyiDIblfVQJemZtMu3YZmowqdE+1k4A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1763483087; 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=Llrc7nT3cZqRcsR9CJkYvm5PhXqkejZRpjAZVy1MxeE=; b=CHkozCd38xOQoUBjEngsfiNeY6MCFWdcvNTcOu+3f0OE8H8kLxwh8n68NvxephJ46YV5YM VXFiZ6aRY5VpmIAYmEUFtJDWJqPdPRUx+WqMwI0CkBH91sZchctJZ19JKqaSiFOMsWbLM4 FSy5cfzjn0lU0/HRdFKr9ypbWYQBGcopFMFTMwfpwLN1LYpmfMdt9095BLZY3TrZNDq5t4 TZqAtkalXOUBDzXRz855X1KSzzjz23Sr6+MK7obOzKr1qrOhkEWvreHhQ1pxgWAr/4kX2/ zdnRDI5UO+Cq3MlvfzrpgTm3SXl+X31Gtw7Swh4r4T4kruch6s1mCyVyoDGfIw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1763483087; a=rsa-sha256; cv=none; b=AxCZ+nykHMm1j21FTp7rRgvoxhrg+YJhiy6vsy4NN8Atd+279OScfdg/v63ncMyZCOjXSr IuUAsTAmzN3Ey5W7HwLEOZdO5M3r2i1JXSMD+Yy1bK5WyslbSKMgns+XYidqS4w3wOTo25 ohkM7BsAS9u21Zoh3ao6NwVPCGJznAKBRwMjF2sDwyDC7xWdQfQvGkxqfXPzdw7z7LDUK+ Wi8iLEzaTBPQRzqIVLnGEbPLWK6oXMM2U6dnZuLHikTrFoNynCyTTk5wf6+B3vSjZ2LS1h 7C5b604b0U74NH5L5Wu9346+GgqOicmhxGZaX4feh4M1RnUNPSjsLfYvqguCkw== 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 4d9qhH27phz11sm for ; Tue, 18 Nov 2025 16:24:47 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 3f040 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 18 Nov 2025 16:24:47 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: d795c753e262 - main - kevent: Hold the knlist mutex when invoking f_event(NOTE_FORK) List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@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/main X-Git-Reftype: branch X-Git-Commit: d795c753e262b97a93dc353aa66b858e1b1969d1 Auto-Submitted: auto-generated Date: Tue, 18 Nov 2025 16:24:47 +0000 Message-Id: <691c9dcf.3f040.6dbd3106@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=d795c753e262b97a93dc353aa66b858e1b1969d1 commit d795c753e262b97a93dc353aa66b858e1b1969d1 Author: Mark Johnston AuthorDate: 2025-11-18 14:22:04 +0000 Commit: Mark Johnston CommitDate: 2025-11-18 16:24:21 +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 --- 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 1baa24d278bf..a48408fd482a 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); }