From owner-dev-commits-src-all@freebsd.org Mon Feb 8 19:46:04 2021 Return-Path: Delivered-To: dev-commits-src-all@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 90CA153EE32; Mon, 8 Feb 2021 19:46:04 +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 4DZGjS3kMTz4l78; Mon, 8 Feb 2021 19:46:04 +0000 (UTC) (envelope-from git@FreeBSD.org) 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 72DE91D0D9; Mon, 8 Feb 2021 19:46:04 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 118Jk4lO007560; Mon, 8 Feb 2021 19:46:04 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 118Jk4sN007559; Mon, 8 Feb 2021 19:46:04 GMT (envelope-from git) Date: Mon, 8 Feb 2021 19:46:04 GMT Message-Id: <202102081946.118Jk4sN007559@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: b57704702762 - main - mca: Handle inconsistent CMCI capability reporting MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: b5770470276268acef21368b3e77a325df883500 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Feb 2021 19:46:04 -0000 The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=b5770470276268acef21368b3e77a325df883500 commit b5770470276268acef21368b3e77a325df883500 Author: Mark Johnston AuthorDate: 2021-02-08 19:42:54 +0000 Commit: Mark Johnston CommitDate: 2021-02-08 19:42:54 +0000 mca: Handle inconsistent CMCI capability reporting A BIOS bug may apparently cause the BSP to report that it does not implement CMCI, with some APs reporting that they do. In this scenario, avoid a NULL pointer dereference that occurs in cmci_monitor() because cmc_state was not allocated by the BSP. PR: 253272 Reported by: asomers, mmacy Reviewed by: kib (previous version) MFC after: 1 week --- sys/x86/x86/mca.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/sys/x86/x86/mca.c b/sys/x86/x86/mca.c index 03100e77d455..801e18073a52 100644 --- a/sys/x86/x86/mca.c +++ b/sys/x86/x86/mca.c @@ -1070,6 +1070,20 @@ cmci_monitor(int i) KASSERT(i < mca_banks, ("CPU %d has more MC banks", PCPU_GET(cpuid))); + /* + * It is possible for some APs to report CMCI support even if the BSP + * does not, apparently due to a BIOS bug. + */ + if (cmc_state == NULL) { + if (bootverbose) { + printf( + "AP %d (%d,%d) reports CMCI support but the BSP does not\n", + PCPU_GET(cpuid), PCPU_GET(apic_id), + PCPU_GET(acpi_id)); + } + return; + } + ctl = rdmsr(MSR_MC_CTL2(i)); if (ctl & MC_CTL2_CMCI_EN) /* Already monitored by another CPU. */ @@ -1114,6 +1128,10 @@ cmci_resume(int i) KASSERT(i < mca_banks, ("CPU %d has more MC banks", PCPU_GET(cpuid))); + /* See cmci_monitor(). */ + if (cmc_state == NULL) + return; + /* Ignore banks not monitored by this CPU. */ if (!(PCPU_GET(cmci_mask) & 1 << i)) return;