From patchwork Mon Jan 13 17:08:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 11330641 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3C13F921 for ; Mon, 13 Jan 2020 17:11:19 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1A2952080D for ; Mon, 13 Jan 2020 17:11:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="I9fqP3J4"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="ltBD6+si" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A2952080D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date:To:Subject: From:References:In-Reply-To:Message-Id:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=QHBgYhMy9+rSULiaekpFDrNmxclOhcLrIyS/Y4GT0Eg=; b=I9fqP3J4VQcfxcurux2uHD7mqc d6yrC2EZUaXmHsttuk/j5OjI18EKw+U2NT1yg31xwmuKJwxUkFeTLUaRQUhAX736hsHIl0J9oIC/T gi7ZlSYtBn07mEA1LnhXKj/S/AQQRxXD1+eXULBHvQv0FIk7InJAGUgVxN1nhAFLZGiAGyJm4hSHy HH7RVZh453c9P5GYOxHtqu1zP6dxaIsx9RH7fIlS7kwqLAV1soCx4latDzSIT7iHMtGWBU1dTcaJw Drax1ZPsu2a+slxsevC/ZEhsQ+txvQWrtroyRifxnWqZVpSeWEpYJk07wGSA+dNhTR9zTf36H3uCT 0gRTyhNg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1ir3FG-0005oj-3v; Mon, 13 Jan 2020 17:11:18 +0000 Received: from pegase1.c-s.fr ([93.17.236.30]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1ir3Cu-0002P1-08 for linux-arm-kernel@lists.infradead.org; Mon, 13 Jan 2020 17:08:54 +0000 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 47xKms1KbYz9v0Y0; Mon, 13 Jan 2020 18:08:45 +0100 (CET) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=ltBD6+si; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id 2grE1wQ3VL1l; Mon, 13 Jan 2020 18:08:45 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 47xKms0BhPz9v0Xy; Mon, 13 Jan 2020 18:08:45 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1578935325; bh=XLnzIcQo2gdn6/h4SDeOO8peJAxsTTmgC8iXnixatHk=; h=In-Reply-To:References:From:Subject:To:Cc:Date:From; b=ltBD6+siFYlWWG5dz6TSocWL3jpuQkzoWPC3xPxE01ZHvMRMiVv8yn+46Fn1vDAQs 162dR8qUJMY1/1TefqinYBAAfHQyr5UsbSxiugQLjDb7t5oItKvK/H3exuotlqfipX mp3zxCOe4hj+Y66sTj0SUCkp01MdjmZBIT0gxDk4= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 563FC8B7C9; Mon, 13 Jan 2020 18:08:50 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id nXhUeUXxlMgG; Mon, 13 Jan 2020 18:08:50 +0100 (CET) Received: from po14934vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 249F18B7BE; Mon, 13 Jan 2020 18:08:50 +0100 (CET) Received: by localhost.localdomain (Postfix, from userid 0) id E5E5D64A1D; Mon, 13 Jan 2020 17:08:49 +0000 (UTC) Message-Id: In-Reply-To: References: From: Christophe Leroy Subject: [RFC PATCH v3 11/12] lib: vdso: split clock verification out of __arch_get_hw_counter() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , arnd@arndb.de, tglx@linutronix.de, vincenzo.frascino@arm.com, luto@kernel.org Date: Mon, 13 Jan 2020 17:08:49 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200113_090852_271708_4BD13221 X-CRM114-Status: UNSURE ( 9.81 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [93.17.236.30 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org __arch_get_hw_counter() returns the current value of the counter if the counter is valid or a negative number if the counter is not valid. This is suboptimal because the validity is checked twice: once before reading the counter and once after reading the counter. Optionaly split the verification out of __arch_get_hw_counter() by providing an optional __arch_is_hw_counter_valid() function. Signed-off-by: Christophe Leroy --- lib/vdso/gettimeofday.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index ea1a55507af5..001f6329e846 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -67,11 +67,18 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk, do { seq = vdso_read_begin(vd); +#ifdef __arch_is_hw_counter_valid + if (unlikely(!__arch_is_hw_counter_valid(vd->clock_mode))) + return -1; +#endif + cycles = __arch_get_hw_counter(vd->clock_mode); ns = vdso_ts->nsec; last = vd->cycle_last; +#ifndef __arch_is_hw_counter_valid if (unlikely((s64)cycles < 0)) return -1; +#endif ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult); nsec = ns >> vd->shift;