From nobody Sat Feb 7 15:11:14 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 40E1815EFDE; Mon, 25 Mar 2024 06:41:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.9 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711348879; cv=none; b=BkeO8AxC+ap8l7zMes2aj+Es4rLB6ydfAADSvfh34cowfrNeThDwXnjCmDSnJCaqBxNus/ZYmSkCTR8dfTyhjUeO9E2IKY1mQfNAF2rjBvg2dxTJc4nZP3GJBQNVdHSCZM3b9ZNJs/Y3AHKZa4gbjWnAnxPukSLvUaBCHwL727c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711348879; c=relaxed/simple; bh=Exf/ex05wg/ZdHrQtagsjpQZFoomRp7dCTSrSntMNmc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=HNxqlXLfCbZDGXBL2O+exk8c1nf1LfRptNoboCsNYST/kydEjhwoxFmb3XkSxg52b4/0UfvgSAwDEnj46kjO/XkSP6I2DxEOA52cUCOcF26hNnbxdFlkdYDghec+I6z2tMnv+9z3Q+EUbvYa+7QPVODbzlORAxJQjE5Ea9Yttu8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=axHArCxd; arc=none smtp.client-ip=192.198.163.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="axHArCxd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1711348878; x=1742884878; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Exf/ex05wg/ZdHrQtagsjpQZFoomRp7dCTSrSntMNmc=; b=axHArCxdlLJWcdpUdFpdUKDb4vGFMy8xAeYle9WYj4wO9bYvG0qfdVB+ e519CX6ze37Otw54tKE+4S5TEfFzN1kkyHo5LuP30R3udjLM+5En+xL05 JX2dw4TKgWIbI2ZBqsuM9eGRWj0h1Qlsr71U6qh29hUykxzWK+CwNb777 a2kJX2K4lHYWJgK9IHChPfcU287b7Ne3lNeHhYfz/LcdeAGexjyG9jbS9 WR1rC31mVvhcTVuc7p2PGV/TJ8t8calE2Pl9bUuvI2nj91QyYDKaLyYxR lgAQcSl4FRyahAaRgXzLlA4RbxPCVk/pany5AANWQGquvMYwMf34SDG8g w==; X-IronPort-AV: E=McAfee;i="6600,9927,11023"; a="17065180" X-IronPort-AV: E=Sophos;i="6.07,152,1708416000"; d="scan'208";a="17065180" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2024 23:41:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,152,1708416000"; d="scan'208";a="38629593" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO ahunter-VirtualBox.home\044ger.corp.intel.com) ([10.251.211.155]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2024 23:41:11 -0700 From: Adrian Hunter To: Thomas Gleixner Cc: Michael Ellerman , Nicholas Piggin , Christophe Leroy , "Aneesh Kumar K.V" , "Naveen N. Rao" , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andy Lutomirski , Vincenzo Frascino , John Stultz , Stephen Boyd , Peter Zijlstra , Randy Dunlap , Bjorn Helgaas , Arnd Bergmann , Anna-Maria Behnsen , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH V2 06/19] vdso: Add vdso_data::max_cycles Date: Mon, 25 Mar 2024 08:40:10 +0200 Message-Id: <20240325064023.2997-7-adrian.hunter@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240325064023.2997-1-adrian.hunter@intel.com> References: <20240325064023.2997-1-adrian.hunter@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add vdso_data::max_cycles in preparation to use it to detect potential multiplication overflow. Suggested-by: Thomas Gleixner Signed-off-by: Adrian Hunter --- include/vdso/datapage.h | 4 ++++ kernel/time/vsyscall.c | 6 ++++++ 2 files changed, 10 insertions(+) diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h index 5d5c0b8efff2..6c3d67d6b758 100644 --- a/include/vdso/datapage.h +++ b/include/vdso/datapage.h @@ -67,6 +67,7 @@ struct vdso_timestamp { * @seq: timebase sequence counter * @clock_mode: clock mode * @cycle_last: timebase at clocksource init + * @max_cycles: maximum cycles which won't overflow 64bit multiplication * @mask: clocksource mask * @mult: clocksource multiplier * @shift: clocksource shift @@ -98,6 +99,9 @@ struct vdso_data { =20 s32 clock_mode; u64 cycle_last; +#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT + u64 max_cycles; +#endif u64 mask; u32 mult; u32 shift; diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c index f0d5062d9cbc..9193d6133e5d 100644 --- a/kernel/time/vsyscall.c +++ b/kernel/time/vsyscall.c @@ -22,10 +22,16 @@ static inline void update_vdso_data(struct vdso_data *v= data, u64 nsec, sec; =20 vdata[CS_HRES_COARSE].cycle_last =3D tk->tkr_mono.cycle_last; +#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT + vdata[CS_HRES_COARSE].max_cycles =3D tk->tkr_mono.clock->max_cycles; +#endif vdata[CS_HRES_COARSE].mask =3D tk->tkr_mono.mask; vdata[CS_HRES_COARSE].mult =3D tk->tkr_mono.mult; vdata[CS_HRES_COARSE].shift =3D tk->tkr_mono.shift; vdata[CS_RAW].cycle_last =3D tk->tkr_raw.cycle_last; +#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT + vdata[CS_RAW].max_cycles =3D tk->tkr_raw.clock->max_cycles; +#endif vdata[CS_RAW].mask =3D tk->tkr_raw.mask; vdata[CS_RAW].mult =3D tk->tkr_raw.mult; vdata[CS_RAW].shift =3D tk->tkr_raw.shift; --=20 2.34.1