From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CC91C072B1 for ; Thu, 30 May 2019 03:44:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 767D124C62 for ; Thu, 30 May 2019 03:44:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559187861; bh=zQQnryd0EY5ERoduf4uCeUOG8dBNAG/t5R4WeZv8cLI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QTryBw+ngIaEXj0ZIZD1EdxLyDjguXRl59GwgHcjaeDtuY56okkES6Tg1b9qQLx31 1bT/0xxtOA2mqtZwgs//D7quwf7Z2FssY80ygXKuD50CEJeSBlddSqeDWqTv1TI/QO ObldBI0fT33xu3RtWB0t4zfuT7lsDcK2ScacdMeA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732393AbfE3DU6 (ORCPT ); Wed, 29 May 2019 23:20:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:60662 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730584AbfE3DU5 (ORCPT ); Wed, 29 May 2019 23:20:57 -0400 Received: from localhost (ip67-88-213-2.z213-88-67.customer.algx.net [67.88.213.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A993124994; Thu, 30 May 2019 03:20:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559186456; bh=zQQnryd0EY5ERoduf4uCeUOG8dBNAG/t5R4WeZv8cLI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vvWzQXzKsPnfp/Dht+uBiR8tNnzbU7wJHOFS1c4s+tptSPCoxnWjzZ9b7mIZbQe5Z vZeyLsX6Z8jmMRFCvpCkrJuJ5b/JvZSsvJuZF0lvwkNT2EqL55UrnmWFM2ua3K45VI HN1UBqRBhVelUzMLAGaYilXH5kIgfg2GYRIuuIag= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Catalin Marinas , Vincenzo Frascino , Will Deacon , Sasha Levin Subject: [PATCH 4.9 070/128] arm64: vdso: Fix clock_getres() for CLOCK_REALTIME Date: Wed, 29 May 2019 20:06:42 -0700 Message-Id: <20190530030447.300845503@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190530030432.977908967@linuxfoundation.org> References: <20190530030432.977908967@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 81fb8736dd81da3fe94f28968dac60f392ec6746 ] clock_getres() in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; where 'hrtimer_resolution' depends on whether or not high resolution timers are enabled, which is a runtime decision. The vDSO incorrectly returns the constant CLOCK_REALTIME_RES. Fix this by exposing 'hrtimer_resolution' in the vDSO datapage and returning that instead. Reviewed-by: Catalin Marinas Signed-off-by: Vincenzo Frascino [will: Use WRITE_ONCE(), move adr off COARSE path, renumber labels, use 'w' reg] Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/include/asm/vdso_datapage.h | 1 + arch/arm64/kernel/asm-offsets.c | 2 +- arch/arm64/kernel/vdso.c | 3 +++ arch/arm64/kernel/vdso/gettimeofday.S | 7 +++---- 4 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h index 2b9a63771eda8..f89263c8e11af 100644 --- a/arch/arm64/include/asm/vdso_datapage.h +++ b/arch/arm64/include/asm/vdso_datapage.h @@ -38,6 +38,7 @@ struct vdso_data { __u32 tz_minuteswest; /* Whacky timezone stuff */ __u32 tz_dsttime; __u32 use_syscall; + __u32 hrtimer_res; }; #endif /* !__ASSEMBLY__ */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index bd239b1b7a681..95878bea27f93 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -92,7 +92,7 @@ int main(void) DEFINE(CLOCK_REALTIME, CLOCK_REALTIME); DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC); DEFINE(CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_RAW); - DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC); + DEFINE(CLOCK_REALTIME_RES, offsetof(struct vdso_data, hrtimer_res)); DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE); DEFINE(CLOCK_MONOTONIC_COARSE,CLOCK_MONOTONIC_COARSE); DEFINE(CLOCK_COARSE_RES, LOW_RES_NSEC); diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 4bcfe01b5aad4..c9b9a5a322eb1 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -213,6 +213,9 @@ void update_vsyscall(struct timekeeper *tk) vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec; vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec; + /* Read without the seqlock held by clock_getres() */ + WRITE_ONCE(vdso_data->hrtimer_res, hrtimer_resolution); + if (!use_syscall) { /* tkr_mono.cycle_last == tkr_raw.cycle_last */ vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last; diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index 76320e9209651..df829c4346fac 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -301,13 +301,14 @@ ENTRY(__kernel_clock_getres) ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne b.ne 1f - ldr x2, 5f + adr vdso_data, _vdso_data + ldr w2, [vdso_data, #CLOCK_REALTIME_RES] b 2f 1: cmp w0, #CLOCK_REALTIME_COARSE ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne b.ne 4f - ldr x2, 6f + ldr x2, 5f 2: cbz w1, 3f stp xzr, x2, [x1] @@ -321,8 +322,6 @@ ENTRY(__kernel_clock_getres) svc #0 ret 5: - .quad CLOCK_REALTIME_RES -6: .quad CLOCK_COARSE_RES .cfi_endproc ENDPROC(__kernel_clock_getres) -- 2.20.1