From nobody Fri Mar 22 18:40:14 2024 X-Original-To: dev-commits-src-branches@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 4V1WNG5jXqz5F3sl; Fri, 22 Mar 2024 18:40:14 +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 "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4V1WNG3cXLz4rll; Fri, 22 Mar 2024 18:40:14 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1711132814; 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=oWNIYnnbUZxwZlnz/kclxKTIxf0SCz1fg6LEA7eUrr8=; b=QG+M/JtPEMRtFzQfu5SOIe1nR203HIBGD4nAn50XuFjH+F30PlHm/6qdh4rxyIZ7g1k/T2 C865jsUZGc/BSZjwMU0YSjJ8avY1CEXGI5RQVbafJl/BgYTUcYRz+Xf4qARw1R9ZoFo2HT VD2SiFJF3EKp2wBYr9Wi3kePNO+SbUR1aIPEu7PX3PhgTj4Wg7rVr7XSHBVzd0+wu1I/rC S5M02D1dKLHq4TwXaq+TERk2Jh/MatB4NTZSx7dDDar07rk0/Tj13C1vzTiES+hOhZqRm/ 1Bj2dZeQhD1efVlZrQz9mdZZzyHjcnd6PNcBIgxLXsQRFh29evDI3ZRBMBDSnQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1711132814; a=rsa-sha256; cv=none; b=AQUdXuQ9vyW3kLt+frdlccIB8fhdg0J+nnjTduLmzizMClzwQrqLsV7hYz//x8oAA0E/ta RaktsCY6b1pKBFTHWsX10sIUUaBJzWXJaO1CmKj0S4iJPi07ppvYG4hJfdNzVjnPpF+HNA E/qkO9WQDP70AREa82/erAkwt/SyUyCkLQDjhx3Pjsf7OJOe1a0ddjd4RonCCxa87m62A8 OAzNgtyKDCohPFEer5WjFUgGW4ut4fBaK+3ndy8IoUQtFoR0OgGUNeRFqLdaXaOgDbRHkh nAufShH4rltuSb8prUxSXPXcG44vxuItOJJi371o/cFRpY/jo84KJYHUxtLH/A== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1711132814; 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=oWNIYnnbUZxwZlnz/kclxKTIxf0SCz1fg6LEA7eUrr8=; b=riSWgTAjbOl/BQjr8Z5HhWSeIFCEzk0ZPNuS/NgRR4OVbHGNLKCP3TKgB+Qvcj6fgSV71T fyQ1Iv6YTV+TYTmexYEDtbN+43L8gvVTiVgcyj538Md+A98T04bdlQqDX1xEqKxHF9JIKC S1lcRSg1PoXscKr1y2AFF/rjr2sRCzh5wwGyYr31s7BLM0mrzHGeEUvNYRKPHV7O9q0Svz 7vUGM425rzK6dpWJnCnJehztw6JEtofbvXbcFnF/y3SMEkWRkj32bEhLR+lFiG75PxYH2R uMgDFCcvJ+IC96ceAJpwaQLsygMZ+xWcXnsrY6QaogEJEhw5QqvwnXCEc2Nmaw== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (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 4V1WNG3DvFzFpt; Fri, 22 Mar 2024 18:40:14 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.17.1/8.17.1) with ESMTP id 42MIeEhN019819; Fri, 22 Mar 2024 18:40:14 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.17.1/8.17.1/Submit) id 42MIeEKr019810; Fri, 22 Mar 2024 18:40:14 GMT (envelope-from git) Date: Fri, 22 Mar 2024 18:40:14 GMT Message-Id: <202403221840.42MIeEKr019810@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Kyle Evans Subject: git: 806e51f81dba - stable/13 - if_wg: use proper barriers around pkt->p_state List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-branches@freebsd.org X-BeenThere: dev-commits-src-branches@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kevans X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: 806e51f81dbae21feb6e7ddd95d2ed2a28b04f8f Auto-Submitted: auto-generated The branch stable/13 has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=806e51f81dbae21feb6e7ddd95d2ed2a28b04f8f commit 806e51f81dbae21feb6e7ddd95d2ed2a28b04f8f Author: Kyle Evans AuthorDate: 2024-03-15 01:19:18 +0000 Commit: Kyle Evans CommitDate: 2024-03-22 15:21:42 +0000 if_wg: use proper barriers around pkt->p_state Without appropriate load-synchronization to pair with store barriers in wg_encrypt() and wg_decrypt(), the compiler and hardware are often allowed to reorder these loads in wg_deliver_out() and wg_deliver_in() such that we end up with a garbage or intermediate mbuf that we try to pass on. The issue is particularly prevalent with the weaker memory models of !x86 platforms. Switch from the big-hammer wmb() to more explicit acq/rel atomics to both make it obvious what we're syncing up with, and to avoid somewhat hefty fences on platforms that don't necessarily need this. With this patch, my dual-iperf3 reproducer is dramatically more stable than it is without on aarch64. PR: 264115 Reviewed by: andrew, zlei (cherry picked from commit 3705d679a6344c957cae7a1b6372a8bfb8c44f0e) --- sys/dev/wg/if_wg.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/sys/dev/wg/if_wg.c b/sys/dev/wg/if_wg.c index 89b5e52b7b2b..6638524301b8 100644 --- a/sys/dev/wg/if_wg.c +++ b/sys/dev/wg/if_wg.c @@ -1519,8 +1519,7 @@ wg_encrypt(struct wg_softc *sc, struct wg_packet *pkt) state = WG_PACKET_CRYPTED; out: pkt->p_mbuf = m; - wmb(); - pkt->p_state = state; + atomic_store_rel_int(&pkt->p_state, state); GROUPTASK_ENQUEUE(&peer->p_send); noise_remote_put(remote); } @@ -1592,8 +1591,7 @@ wg_decrypt(struct wg_softc *sc, struct wg_packet *pkt) state = WG_PACKET_CRYPTED; out: pkt->p_mbuf = m; - wmb(); - pkt->p_state = state; + atomic_store_rel_int(&pkt->p_state, state); GROUPTASK_ENQUEUE(&peer->p_recv); noise_remote_put(remote); } @@ -1649,7 +1647,7 @@ wg_deliver_out(struct wg_peer *peer) wg_peer_get_endpoint(peer, &endpoint); while ((pkt = wg_queue_dequeue_serial(&peer->p_encrypt_serial)) != NULL) { - if (pkt->p_state != WG_PACKET_CRYPTED) + if (atomic_load_acq_int(&pkt->p_state) != WG_PACKET_CRYPTED) goto error; m = pkt->p_mbuf; @@ -1691,7 +1689,7 @@ wg_deliver_in(struct wg_peer *peer) struct epoch_tracker et; while ((pkt = wg_queue_dequeue_serial(&peer->p_decrypt_serial)) != NULL) { - if (pkt->p_state != WG_PACKET_CRYPTED) + if (atomic_load_acq_int(&pkt->p_state) != WG_PACKET_CRYPTED) goto error; m = pkt->p_mbuf;