From nobody Mon Sep 06 23:44:43 2021 X-Original-To: bugs@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 4525F17B6095 for ; Mon, 6 Sep 2021 23:44:44 +0000 (UTC) (envelope-from bugzilla-noreply@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 "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4H3Q3v1fy9z4ft9 for ; Mon, 6 Sep 2021 23:44:43 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (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 did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 1A90127E35 for ; Mon, 6 Sep 2021 23:44:43 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 186NihLh020749 for ; Mon, 6 Sep 2021 23:44:43 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from bugzilla@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 186Nih3O020748 for bugs@FreeBSD.org; Mon, 6 Sep 2021 23:44:43 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: bugzilla set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 258310] kevent() does not see signal with zero timeout Date: Mon, 06 Sep 2021 23:44:43 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 13.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: commit-hook@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Bug reports List-Archive: https://lists.freebsd.org/archives/freebsd-bugs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-bugs@freebsd.org MIME-Version: 1.0 X-ThisMailContainsUnwantedMimeParts: N https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D258310 --- Comment #4 from commit-hook@FreeBSD.org --- A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=3D98168a6e6c12dab8f608f6b5f5b0b175d= 2b87ef0 commit 98168a6e6c12dab8f608f6b5f5b0b175d2b87ef0 Author: Konstantin Belousov AuthorDate: 2021-09-06 11:43:06 +0000 Commit: Konstantin Belousov CommitDate: 2021-09-06 23:43:34 +0000 kqueue: drain kqueue taskqueue if syscall tickled it Otherwise return from the syscall and next syscall, which could be kevent(2) on the kqueue that should be notified, races with the kqueue taskqueue thread, and potentially misses the wakeup. This is reliably visible when kevent(2) only peeks into events using zeroed timeout. PR: 258310 Reported by: arichardson, Jan Kokem=C3=BCller Reviewed by: arichardson, markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D31858 sys/kern/kern_event.c | 11 +++++++++++ sys/kern/subr_trap.c | 7 ++++++- sys/sys/event.h | 1 + sys/sys/proc.h | 2 +- 4 files changed, 19 insertions(+), 2 deletions(-) --=20 You are receiving this mail because: You are the assignee for the bug.=