From patchwork Tue Apr 16 16:14:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincenzo Frascino X-Patchwork-Id: 10903395 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 8EB6F13B5 for ; Tue, 16 Apr 2019 16:14:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 786802074F for ; Tue, 16 Apr 2019 16:14:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6C373286BF; Tue, 16 Apr 2019 16:14:56 +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 7A23A2074F for ; Tue, 16 Apr 2019 16:14:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728093AbfDPQOz (ORCPT ); Tue, 16 Apr 2019 12:14:55 -0400 Received: from foss.arm.com ([217.140.101.70]:58736 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726037AbfDPQOy (ORCPT ); Tue, 16 Apr 2019 12:14:54 -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 33ADA15A2; Tue, 16 Apr 2019 09:14:54 -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 626E33F59C; Tue, 16 Apr 2019 09:14:51 -0700 (PDT) From: Vincenzo Frascino To: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , Greentime Hu , Vincent Chen , Shuah Khan , Thomas Gleixner , Arnd Bergmann Subject: [PATCH v2 1/5] arm64: Fix vDSO clock_getres() Date: Tue, 16 Apr 2019 17:14:30 +0100 Message-Id: <20190416161434.32691-2-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190416161434.32691-1-vincenzo.frascino@arm.com> References: <20190416161434.32691-1-vincenzo.frascino@arm.com> 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. Fix the arm64 vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino Reviewed-by: Catalin Marinas --- arch/arm64/include/asm/vdso_datapage.h | 1 + arch/arm64/kernel/asm-offsets.c | 2 +- arch/arm64/kernel/vdso.c | 2 ++ arch/arm64/kernel/vdso/gettimeofday.S | 22 +++++++++++----------- 4 files changed, 15 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h index 2b9a63771eda..f89263c8e11a 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 7f40dcbdd51d..e10e2a5d9ddc 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -94,7 +94,7 @@ 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 2d419006ad43..5f5759d51c33 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -245,6 +245,8 @@ void update_vsyscall(struct timekeeper *tk) vdso_data->cs_shift = tk->tkr_mono.shift; } + vdso_data->hrtimer_res = hrtimer_resolution; + smp_wmb(); ++vdso_data->tb_seq_count; } diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index c39872a7b03c..e2e9dfe9ba4a 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -296,32 +296,32 @@ ENDPROC(__kernel_clock_gettime) /* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */ ENTRY(__kernel_clock_getres) .cfi_startproc + adr vdso_data, _vdso_data cmp w0, #CLOCK_REALTIME ccmp w0, #CLOCK_MONOTONIC, #0x4, ne ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne - b.ne 1f + b.ne 2f - ldr x2, 5f - b 2f -1: +1: /* Get hrtimer_res */ + ldr x2, [vdso_data, #CLOCK_REALTIME_RES] + b 3f +2: cmp w0, #CLOCK_REALTIME_COARSE ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne - b.ne 4f + b.ne 5f ldr x2, 6f -2: - cbz x1, 3f +3: + cbz x1, 4f stp xzr, x2, [x1] -3: /* res == NULL. */ +4: /* res == NULL. */ mov w0, wzr ret -4: /* Syscall fallback. */ +5: /* Syscall fallback. */ mov x8, #__NR_clock_getres svc #0 ret -5: - .quad CLOCK_REALTIME_RES 6: .quad CLOCK_COARSE_RES .cfi_endproc