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 426EEC28CC0 for ; Thu, 30 May 2019 03:12:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C6B32449A for ; Thu, 30 May 2019 03:12:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559185968; bh=mcd2FS0t0z1bCwO4klx+xNkmovjnhdydm2bFSiWeul0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uDND4+rNnpI5mrfrDb17iglkLAwHTdVpVNsNPms/IMOo93gy/6p81tcm5peiQyWcp Vqj95DjNnMqIMPyIzx97uhMugY8KHrfZAc0VUZy3478fPROuf8glkjdDqlEs0T0x63 qj5DMHYf+oD5iDTNx4wFqZrX1yPTDOlPquPU9SV8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729231AbfE3DMr (ORCPT ); Wed, 29 May 2019 23:12:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:49964 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728421AbfE3DLN (ORCPT ); Wed, 29 May 2019 23:11:13 -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 EC5A5244D8; Thu, 30 May 2019 03:11:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559185873; bh=mcd2FS0t0z1bCwO4klx+xNkmovjnhdydm2bFSiWeul0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xdvcxNCXCDEM9Yyc43pcEkMLcomFkw/mKdUEDqYDWtlIusEN5GuX2HHHdbQSHe92/ YkduuaQzLjfg54B7MuLgJTGTVyj0vyzu+5xcIdw0Qq6q1yGbXA3OEbPto6uK8med7q mhXU+whhEuRlxtP5GXnztHowRLUnpjy5b3GPi10A= 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 5.1 190/405] arm64: vdso: Fix clock_getres() for CLOCK_REALTIME Date: Wed, 29 May 2019 20:03:08 -0700 Message-Id: <20190530030550.629262924@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190530030540.291644921@linuxfoundation.org> References: <20190530030540.291644921@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 7f40dcbdd51d0..e10e2a5d9ddcf 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 2d419006ad433..ec0bb588d7553 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -232,6 +232,9 @@ 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 e8f60112818fc..856fee6d35129 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -308,13 +308,14 @@ 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 x1, 3f stp xzr, x2, [x1] @@ -328,8 +329,6 @@ 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