From patchwork Fri Mar 8 13:14:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 1909702 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=KDPO3FHj; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=patchwork.ozlabs.org) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4Trn2l176Pz1yWx for ; Sat, 9 Mar 2024 00:24:47 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=KDPO3FHj; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Trn2l03Fbz3vdt for ; Sat, 9 Mar 2024 00:24:47 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=KDPO3FHj; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=intel.com (client-ip=192.198.163.9; helo=mgamail.intel.com; envelope-from=adrian.hunter@intel.com; receiver=lists.ozlabs.org) 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 lists.ozlabs.org (Postfix) with ESMTPS id 4Trmt21fJ8z3vXK for ; Sat, 9 Mar 2024 00:17:14 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1709903834; x=1741439834; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Exf/ex05wg/ZdHrQtagsjpQZFoomRp7dCTSrSntMNmc=; b=KDPO3FHjpzgry90cCUoO13BtX9V3p1XKSg60ftRsJwYjOehbdEnl+sGh wrE/hzy2y+Et8Tlntrz0+2P6jzKnQFPB4nFxoS9NpHzyU2ftrqJGNOaXe utGP9SAta9ZwIwTZn0O9EzgviLbUzQFF9lya7R1KmTLaZLYq6LSyClTRk 0ISRGxS7lA6okEj+LVgQSsQRqSKvy0mjiWyKYwZwR90lXaUoft4a6iOoL 6eszbRN4to18Jb1J5O6yRyCen6nXu7s/Z4JhNuk/e2Ye6IHIq7tCZOnq7 xO8v4MnAyjx/UB1VNYRmqrj3DSJOERyjzUvIpc02qMd11MKPatInq78fN w==; X-IronPort-AV: E=McAfee;i="6600,9927,11006"; a="15342540" X-IronPort-AV: E=Sophos;i="6.07,109,1708416000"; d="scan'208";a="15342540" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2024 05:16:10 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,109,1708416000"; d="scan'208";a="15161409" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO ahunter-VirtualBox.home\044ger.corp.intel.com) ([10.249.46.63]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2024 05:16:02 -0800 From: Adrian Hunter To: Thomas Gleixner Subject: [PATCH 06/19] vdso: Add vdso_data::max_cycles Date: Fri, 8 Mar 2024 15:14:59 +0200 Message-Id: <20240308131512.44324-7-adrian.hunter@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240308131512.44324-1-adrian.hunter@intel.com> References: <20240308131512.44324-1-adrian.hunter@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , Dave Hansen , John Stultz , "H. Peter Anvin" , Alexander Gordeev , Vincenzo Frascino , linux-s390@vger.kernel.org, Arnd Bergmann , x86@kernel.org, "Aneesh Kumar K.V" , Ingo Molnar , "Naveen N. Rao" , Christian Borntraeger , Vasily Gorbik , Heiko Carstens , Nicholas Piggin , Borislav Petkov , Andy Lutomirski , Bjorn Helgaas , Anna-Maria Behnsen , Stephen Boyd , Randy Dunlap , linux-kernel@vger.kernel.org, Sven Schnelle , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 { 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 *vdata, u64 nsec, sec; vdata[CS_HRES_COARSE].cycle_last = tk->tkr_mono.cycle_last; +#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT + vdata[CS_HRES_COARSE].max_cycles = tk->tkr_mono.clock->max_cycles; +#endif vdata[CS_HRES_COARSE].mask = tk->tkr_mono.mask; vdata[CS_HRES_COARSE].mult = tk->tkr_mono.mult; vdata[CS_HRES_COARSE].shift = tk->tkr_mono.shift; vdata[CS_RAW].cycle_last = tk->tkr_raw.cycle_last; +#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT + vdata[CS_RAW].max_cycles = tk->tkr_raw.clock->max_cycles; +#endif vdata[CS_RAW].mask = tk->tkr_raw.mask; vdata[CS_RAW].mult = tk->tkr_raw.mult; vdata[CS_RAW].shift = tk->tkr_raw.shift;