From nobody Mon Oct 06 16:00:17 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 4cgP9s65Fdz69Zlj; Mon, 06 Oct 2025 16:00:17 +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 4cgP9s5Zsxz3hSy; Mon, 06 Oct 2025 16:00:17 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1759766417; 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=bjCCmnsh86Utx/fCJi05hfwcabbftHgNxqSSCcqILzM=; b=NdOvwxQjYRUBmUVqm+iHCmawUeykPc2KKn9fIGs0N5OATIpQdS+Qh8XoLImqxSr0Lld9yD tPU2KNE2r8idsbOydPPcD1BXle35Kl0KZW3Yf4iEt0c5OtSZhPfiZT+qZN1W84fhaEVIw4 58K+ORgvnEnLAcnZ/vSkSEp4zvIMc1/VkNwIELJiP2430ZdsLNx7ejM3yi4PoEtKJM18/i O3nkhqO1koqLN+VyAi3t9aCzN1tUmIdZvD+fUjImnrvzZOSXIHf9BObNz06gAHONFY2qLw CQAngx84k6dqfcJ4goWTDVcF5YlQ65KBNqX3h9/xHyp+bPmbCWTHuBYtNKiC5Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1759766417; 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=bjCCmnsh86Utx/fCJi05hfwcabbftHgNxqSSCcqILzM=; b=t5pIFsKv+OcFE7Y41q05iE6IIVBT0bptxJk3l0FjYzg1V5zzr2MnvpGkmUnNVo9uCPJmsp MXluvoHWbI742Xw9KkReEDJrPfGqQCY5WDmmCXivCcLjtOksXY1BCCZv0UiLtI8tN1Ev/0 3r4VOt5qQFvX7r5CY8HFd/E/DZhhHDyyYbk5SUh7UIFTFfJlBa5faT+AHd5+mwkm7QjxrK i7zkI+XWD8vpAEMmsY98yofJWlyq4I/dLNRoDphMpQrHnuUNrUN3vsfw3UFwhAlK6b6aFB DaTeMfmLmqcZT02X+oR2Th21cq8+AIj2Jth0JxZluAROtC7oEtsNFqnMndRcqw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1759766417; a=rsa-sha256; cv=none; b=oxZNXHKHFM7sa4xiYrxd9QFs3K6P60C5oZTOkqoDYuUysNFkvI0fSFrqzkfcS1q0GP8Hta SZvAURq0FukQVzn/6d3sinJ9ciEWDB6xaZYUJT74wtbL2LZAVnKVZlxcKMIAUxRI9+/XML VyWLL7IzcC/p41oqh9Hj9HSVChY32TbQqFzhjrUjY4Hb32R/geg11r5lwPLi2/UL7yq97f QtUauA2Aao+SBsl9h7W820XHqvtYlg3MU5ndvw7eBr8zvLxTDVGWpBAosgdHsf2/a2PKZt uAqMXcGMIttD/Y6eW7AquPPB3qDDbdIegmMrW9TGt+3nOZqG3KnFEPAVtE2fcw== 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 4cgP9s59zZz14TZ; Mon, 06 Oct 2025 16:00:17 +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 596G0HOh011419; Mon, 6 Oct 2025 16:00:17 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 596G0HvD011410; Mon, 6 Oct 2025 16:00:17 GMT (envelope-from git) Date: Mon, 6 Oct 2025 16:00:17 GMT Message-Id: <202510061600.596G0HvD011410@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: "Jonathan T. Looney" Subject: git: 4a5d8670a7d5 - main - x86: Close race condition on MCA task queues at startup 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: jtl X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 4a5d8670a7d58b04913fd90aae85a1e35236ca3d Auto-Submitted: auto-generated The branch main has been updated by jtl: URL: https://cgit.FreeBSD.org/src/commit/?id=4a5d8670a7d58b04913fd90aae85a1e35236ca3d commit 4a5d8670a7d58b04913fd90aae85a1e35236ca3d Author: Jonathan T. Looney AuthorDate: 2025-10-03 16:23:07 +0000 Commit: Jonathan T. Looney CommitDate: 2025-10-06 15:59:31 +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 --- 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);