From nobody Thu Mar 26 19:03:36 2026 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 4fhY8Z1nb6z6WJsM for ; Thu, 26 Mar 2026 19:03:42 +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" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4fhY8Y6nVsz3GXQ for ; Thu, 26 Mar 2026 19:03:41 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1774551821; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=JlPe3uW4tM6l6+gYYUok1qMr0Ufw2/Aw14+/j5WUKXc=; b=O7fIKu6A2QvoFu77xUYh8LdtLPck8Ui83BX4v5hXOlTBoWs1ObY/M5nlKuFwWU7UzqT0DW m+mQu1R1e144G2zFA9jHT7e55bLqbq2NxQvvkMa0LRiUvokhiWnD8tEN0dDd/A7hvPPjiz vTDjrlq2uwnDZhgk9QXNa1Qnya60AhvEmZYleFI9zF4NJvQMkw5nmUsUaoBFbJcjYty+HO YFfLv+pIyzL04ExJqln+Kwyed8OjNwzIv1hSNqQCgiCd83cJRwMozWHWmIlI+MHRTpNEgk WOchW2GP27Zun+1mo/R/DDO5yHAy936Di19ufDgLBRMbXfJNW4+W1yw2aKWCyA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1774551822; a=rsa-sha256; cv=none; b=YTltazGm4wRyIKv/KXtL0xDrpIAzmmesB7AwQQMaLDkiW3wrsdgpXfBl/jGYmNwcg/XIKz HMATjtc/h3PpctJTcpLbMn1ecA0/1To5lvD+i5ZGb8H6Siye8pvYy2DMd9+10GyJbM3WGp hXWcC6pqLRq+Xbno7wmtDnYl4SwK3pT2RaFYN9PmH977Wo92fdroKI4E7m8uaV7rZnaJI2 x87kk2SsTXcpWi1Kr2Wl/h3LpGsgTL6AH86ffXIDFsWOj2MRuualYzFip+1AkdCOI/bCbh d1Rj92ePPbDKXwqXj553jIheKJy354S91Dwjgrn96Saf70awGHKcbjgOinCQUw== 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=1774551821; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=JlPe3uW4tM6l6+gYYUok1qMr0Ufw2/Aw14+/j5WUKXc=; b=NTCxbLd0wPbc8lHkReDyPxv2k8A0QhKXfU4061b4JcaeiovKLXqd+AoUADc+HXcPQayDjQ vyIXhywJxnE/vCTp1MqeL2KEkULKeVuqmt4UjGVrS/nppWnzEMad8Z7wX2C++X1QGnOdyv rD0LU+ewC419eUdlpAoP1U0Y61vm2XJ7KaFNdyR0arNHll2gEFPWxKQuP6JEgifvtaHE/w rzWw9Y5v8w5NWCo7Al4BB3swsgys8CVQ/s9jpzrB2s4hWknEU6zOG7WMwyMoIninFK0B8f RFgDX/6Ag9+dpW7gSvicg3CTPRFq0c4mDpqYs7Rna5sF39dxmuHw9EAStFEU4A== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4fhY8Y5wHfz155S for ; Thu, 26 Mar 2026 19:03:41 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 195e1 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Thu, 26 Mar 2026 19:03:36 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Cc: Matt Delco From: Alexander Ziaee Subject: git: c505fc146884 - main - x86: Guard clock frequency against a divide by 0 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: ziaee X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: c505fc1468849150f48484b225b6476d8316de57 Auto-Submitted: auto-generated Date: Thu, 26 Mar 2026 19:03:36 +0000 Message-Id: <69c58308.195e1.1d1363de@gitrepo.freebsd.org> The branch main has been updated by ziaee: URL: https://cgit.FreeBSD.org/src/commit/?id=c505fc1468849150f48484b225b6476d8316de57 commit c505fc1468849150f48484b225b6476d8316de57 Author: Matt Delco AuthorDate: 2026-03-26 17:22:54 +0000 Commit: Alexander Ziaee CommitDate: 2026-03-26 19:02:06 +0000 x86: Guard clock frequency against a divide by 0 We may be running in a Virtual Machine which may not fully support hardware performance counters. If the MPERF counter somehow ends up at zero, return an error and fail gracefully instead of panicking. This patch is part of Google Cloud Engine (GCE) C4-LSSD turnup. Sponsored by: Google Tested by: NetApp (previous) PR: 292808 MFC after: 3 days Co-authored-by: Aymeric Wibo Co-authored-by: Jim Mattson Suggested by: jrtc27 (split out this part) Reviewed by: imp, obiwac, olce Differential Revision: https://reviews.freebsd.org/D56056 --- sys/x86/x86/cpu_machdep.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/sys/x86/x86/cpu_machdep.c b/sys/x86/x86/cpu_machdep.c index 5483fbd6dd4e..775fee97d3cd 100644 --- a/sys/x86/x86/cpu_machdep.c +++ b/sys/x86/x86/cpu_machdep.c @@ -425,6 +425,7 @@ cpu_est_clockrate(int cpu_id, uint64_t *rate) uint64_t tsc1, tsc2; uint64_t acnt, mcnt, perf; register_t reg; + int error = 0; if (pcpu_find(cpu_id) == NULL || rate == NULL) return (EINVAL); @@ -460,6 +461,11 @@ cpu_est_clockrate(int cpu_id, uint64_t *rate) acnt = rdmsr(MSR_APERF); tsc2 = rdtsc(); intr_restore(reg); + if (mcnt == 0) { + tsc_perf_stat = 0; + error = EOPNOTSUPP; + goto err; + } perf = 1000 * acnt / mcnt; *rate = (tsc2 - tsc1) * perf; } else { @@ -470,6 +476,7 @@ cpu_est_clockrate(int cpu_id, uint64_t *rate) *rate = (tsc2 - tsc1) * 1000; } +err: #ifdef SMP if (smp_cpus > 1) { thread_lock(curthread); @@ -478,7 +485,7 @@ cpu_est_clockrate(int cpu_id, uint64_t *rate) } #endif - return (0); + return (error); } /*