From nobody Thu Oct 09 17:16:05 2025 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 4cjGjx2yC5z6BnXh; Thu, 09 Oct 2025 17:16:05 +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 4cjGjx2FbDz49SL; Thu, 09 Oct 2025 17:16:05 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1760030165; 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=mOSQUaezCX5MngHZ2P0NH+rJICVNFgwUNbVkWgtxodk=; b=UamF7nqvHvfxbwK5+J+D+3LukR6spNUbkQFFvWDl0eNc3YppkwWEBHgi+KL3QXLyBhdHFn crQ2iWXVR8PUNFWrkfF2ZmFJpGXWlOP4droxUvnpL9eTIblIXuAHaiqcCI3eeElD5c/sv3 x5y+FO4M9rnIYMUN5a68zAl1rFHC5YtaWRoM/3WdSyjbliKYf7pjRTovggj9scqo/Wcg4S ssVvCO5amcwTucxiC9+1iO+6msWz1quA5+GEUg0gh4ojofsbZgEErxObesL7DJDYPzf6Po k4opICRRpSs3SqydiEpgPec+0HNcA86fdbnopywrgTuHSC1r7drIC2VDodKToQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1760030165; 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=mOSQUaezCX5MngHZ2P0NH+rJICVNFgwUNbVkWgtxodk=; b=ozXzxKnua+csMWQY6+bTHjnFfhlWYeS119fISpuuakl1qNya57t6kXDpwb8bPbW2zQSqrB 3LxiOSQ86DfTdbuGTxPkNFWJMWxdnN1VfivzBMZnJkQOJ0v2ZPj2sxeDpCWNKCO8V45PIz 8cWw7bNli61Y2RgeHAf5P9/Wg+1f5Tj2lqw1ajdcKknooKSyDBc3wahkaROHQiwXli84+o Jn9tkqgM5nap0jpg5rSvI+q9HRHHBETLBtutlvkOOkT7rxfA8o1jf8isi81mg+40jMojRS Vb3i6mOoJh8dACwQVdDPWKTEbF4GxnU+R1kXuH/2XiPYz7muzogAIiaN8XFBdw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1760030165; a=rsa-sha256; cv=none; b=wypW0cTMENvIh4XAZd87LUAHbvWQjfPhGteN/1X5RtLLR3v8jjhTk7SeooKRv33rIUtsIf CuGHycUoo0cG5fld1H3ryfdCQV6gBaTOa5pkU4ZbOdD9oXiRVQKmAEjkcuzoPqgDC+fwuk GvByXXIgFkMHMcWX/zRWitD9tM4ew29aY8v21zaGFghoRrqXp9c14o+i6hm8UWCTsgtANK YlV6R44LI9uo4Tzrz4JpSE8Umu9SmCjgZBWYrmjgJ3SH8487ZAw9GduwZOAKcIUgOhR6JQ CGOs2OvXfG4WO5Op74v8AzwEAln61OV0yF6UT/rBG+WlzFyXFXC+4VrkQiU7ew== ARC-Authentication-Results: i=1; mx1.freebsd.org; none 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 4cjGjx1hsCz9cF; Thu, 09 Oct 2025 17:16:05 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 599HG5u1001343; Thu, 9 Oct 2025 17:16:05 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 599HG5Me001340; Thu, 9 Oct 2025 17:16:05 GMT (envelope-from git) Date: Thu, 9 Oct 2025 17:16:05 GMT Message-Id: <202510091716.599HG5Me001340@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: "Jonathan T. Looney" Subject: git: 8d0f269989d8 - stable/15 - x86: Close race condition on MCA task queues at startup 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: X-BeenThere: dev-commits-src-branches@freebsd.org Sender: owner-dev-commits-src-branches@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: jtl X-Git-Repository: src X-Git-Refname: refs/heads/stable/15 X-Git-Reftype: branch X-Git-Commit: 8d0f269989d8131f2da0bb9f607163158f9ea2b7 Auto-Submitted: auto-generated The branch stable/15 has been updated by jtl: URL: https://cgit.FreeBSD.org/src/commit/?id=8d0f269989d8131f2da0bb9f607163158f9ea2b7 commit 8d0f269989d8131f2da0bb9f607163158f9ea2b7 Author: Jonathan T. Looney AuthorDate: 2025-10-03 16:23:07 +0000 Commit: Jonathan T. Looney CommitDate: 2025-10-09 17:15:21 +0000 x86: Close race condition on MCA task queues at startup Currently, the CMCI handler checks the cold variable to determine whether it can schedule a task. The task queue is setup as part of the mca_startup() function, which is run well after the configure_final() function sets the cold variable to 0. Therefore, if an MCA arrives in the window between configure_final() and mca_startup() running, the code could try to schedule a task on an unintitalized task queue. Close the race by specifically checking whether the mca_startup() function has run. Reviewed by: markj MFC after: 1 week Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D12276 (cherry picked from commit 4a5d8670a7d58b04913fd90aae85a1e35236ca3d) --- sys/x86/x86/mca.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/sys/x86/x86/mca.c b/sys/x86/x86/mca.c index 1851df8d00a0..933d10e52187 100644 --- a/sys/x86/x86/mca.c +++ b/sys/x86/x86/mca.c @@ -133,6 +133,7 @@ static struct taskqueue *mca_tq; static struct task mca_resize_task; static struct timeout_task mca_scan_task; static struct mtx mca_lock; +static bool mca_startup_done = false; /* Statistics on number of MCA events by type, updated atomically. */ static uint64_t mca_stats[MCA_T_COUNT]; @@ -1025,7 +1026,7 @@ mca_process_records(enum scan_mode mode) mtx_unlock_spin(&mca_lock); if (mode == POLLED) mca_resize_freelist(); - else if (!cold) + else if (mca_startup_done) taskqueue_enqueue(mca_tq, &mca_resize_task); } @@ -1097,7 +1098,7 @@ sysctl_mca_maxcount(SYSCTL_HANDLER_ARGS) doresize = true; } mtx_unlock_spin(&mca_lock); - if (doresize && !cold) + if (doresize && mca_startup_done) taskqueue_enqueue(mca_tq, &mca_resize_task); return (error); } @@ -1115,6 +1116,7 @@ mca_startup(void *dummy) taskqueue_start_threads(&mca_tq, 1, PI_SWI(SWI_TQ), "mca taskq"); taskqueue_enqueue_timeout_sbt(mca_tq, &mca_scan_task, mca_ticks * SBT_1S, 0, C_PREL(1)); + mca_startup_done = true; } SYSINIT(mca_startup, SI_SUB_KICK_SCHEDULER, SI_ORDER_ANY, mca_startup, NULL);