From owner-freebsd-bugs@freebsd.org Wed Nov 27 18:57:22 2019 Return-Path: Delivered-To: freebsd-bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 70E801B4B0C for ; Wed, 27 Nov 2019 18:57:22 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 47NVPt2ClVz4QDB for ; Wed, 27 Nov 2019 18:57:22 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 49C1C1B4B0B; Wed, 27 Nov 2019 18:57:22 +0000 (UTC) Delivered-To: bugs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 4987F1B4B0A for ; Wed, 27 Nov 2019 18:57:22 +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) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 47NVPt0Dd0z4QD9 for ; Wed, 27 Nov 2019 18:57:22 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id DBE5819D03 for ; Wed, 27 Nov 2019 18:57:21 +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 xARIvLZ8071297 for ; Wed, 27 Nov 2019 18:57:21 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id xARIvL0Z071296 for bugs@FreeBSD.org; Wed, 27 Nov 2019 18:57:21 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 242272] LinuxKPI combines all RCU and SRCU domains together, leading to deadlock Date: Wed, 27 Nov 2019 18:57:21 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: aboyer@pensando.io X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Nov 2019 18:57:22 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D242272 Bug ID: 242272 Summary: LinuxKPI combines all RCU and SRCU domains together, leading to deadlock Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: aboyer@pensando.io In that other OS, all RCU code is in the one domain, and each SRCU user gets its own domain. (More or less.) They are all combined together in FreeBSD s= ince it has only a bare-bones implementation in the KPI. This is a problem because ib_uverbs holds an SRCU read lock when calling in= to the provider's destroy_cq function. Providers may expect to be able to use = RCU primitives when tearing down, but calling synchronize_rcu() or synchronize_srcu() will lead to a deadlock, even on a completely separate S= RCU domain. To fix this will require adding real multiple-domain support to the KPI. --=20 You are receiving this mail because: You are the assignee for the bug.=