From patchwork Wed May 22 11:07:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincenzo Frascino X-Patchwork-Id: 10955727 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0F631112C for ; Wed, 22 May 2019 11:07:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EAB2126E1A for ; Wed, 22 May 2019 11:07:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DE3F42882E; Wed, 22 May 2019 11:07:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4EBAA26E1A for ; Wed, 22 May 2019 11:07:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728703AbfEVLHl (ORCPT ); Wed, 22 May 2019 07:07:41 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:48104 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727464AbfEVLHl (ORCPT ); Wed, 22 May 2019 07:07:41 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B4B69341; Wed, 22 May 2019 04:07:40 -0700 (PDT) Received: from e119884-lin.cambridge.arm.com (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7BE073F575; Wed, 22 May 2019 04:07:38 -0700 (PDT) From: Vincenzo Frascino To: linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , Shuah Khan , Thomas Gleixner , Arnd Bergmann Subject: [PATCH v3 0/3] Fix vDSO clock_getres() Date: Wed, 22 May 2019 12:07:19 +0100 Message-Id: <20190522110722.28094-1-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. A possible fix is to change the vdso implementation of clock_getres, keeping a copy of hrtimer_resolution in vdso data and using that directly [1]. This patchset implements the proposed fix for arm64, powerpc, s390, nds32 and adds a test to verify that the syscall and the vdso library implementation of clock_getres return the same values. Even if these patches are unified by the same topic, there is no dependency between them, hence they can be merged singularly by each arch maintainer. Note: arm64 and nds32 respective fixes have been merged in 5.2-rc1, hence they have been removed from this series. [1] https://marc.info/?l=linux-arm-kernel&m=155110381930196&w=2 Changes: -------- v3: - Rebased on 5.2-rc1. - Addressed review comments. v2: - Rebased on 5.1-rc5. - Addressed review comments. Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Shuah Khan Cc: Thomas Gleixner Cc: Arnd Bergmann Signed-off-by: Vincenzo Frascino Vincenzo Frascino (3): powerpc: Fix vDSO clock_getres() s390: Fix vDSO clock_getres() kselftest: Extend vDSO selftest to clock_getres arch/powerpc/include/asm/vdso_datapage.h | 2 + arch/powerpc/kernel/asm-offsets.c | 2 +- arch/powerpc/kernel/time.c | 1 + arch/powerpc/kernel/vdso32/gettimeofday.S | 7 +- arch/powerpc/kernel/vdso64/gettimeofday.S | 7 +- arch/s390/include/asm/vdso.h | 1 + arch/s390/kernel/asm-offsets.c | 2 +- arch/s390/kernel/time.c | 1 + arch/s390/kernel/vdso32/clock_getres.S | 12 +- arch/s390/kernel/vdso64/clock_getres.S | 10 +- tools/testing/selftests/vDSO/Makefile | 2 + .../selftests/vDSO/vdso_clock_getres.c | 137 ++++++++++++++++++ 12 files changed, 168 insertions(+), 16 deletions(-) create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c