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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97C54C5479D for ; Mon, 9 Jan 2023 07:49:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233479AbjAIHtF (ORCPT ); Mon, 9 Jan 2023 02:49:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230458AbjAIHtA (ORCPT ); Mon, 9 Jan 2023 02:49:00 -0500 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 473E313D1B for ; Sun, 8 Jan 2023 23:48:54 -0800 (PST) X-UUID: 58e4959e74f846178f01e511ce0de840-20230109 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=bs2FSxIihXHb6oD1WWcKClwQlo62DnFY7LM0eETIU98=; b=lUcvgIYMKQE/NrQVWMff4Rk5IcBS8pKK6n1hdwu4eZC4HuTA1FrL/Ou0nNyORswl9FsxB2wmKtgMQA/ygQ9wtNh+3+rCXpvJDY+bJDTPNh96q78sgq2HFXeEwXTrIWBgb02lCdECIEz42dqkNEZqvC7ZyKRZs0XPC2rpnC6YiFk=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.17,REQID:cd83526b-aac8-453c-abd3-749a726752fb,IP:0,U RL:0,TC:0,Content:0,EDM:0,RT:0,SF:45,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:45 X-CID-INFO: VERSION:1.1.17,REQID:cd83526b-aac8-453c-abd3-749a726752fb,IP:0,URL :0,TC:0,Content:0,EDM:0,RT:0,SF:45,FILE:0,BULK:0,RULE:Release_Ham,ACTION:r elease,TS:45 X-CID-META: VersionHash:543e81c,CLOUDID:6e8b1554-dd49-462e-a4be-2143a3ddc739,B ulkID:230109154849SCUYYH1B,BulkQuantity:0,Recheck:0,SF:28|17|19|48|102,TC: nil,Content:0,EDM:-3,IP:nil,URL:0,File:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,O SI:0,OSA:0 X-CID-BVR: 1,FCT X-UUID: 58e4959e74f846178f01e511ce0de840-20230109 Received: from mtkmbs10n1.mediatek.inc [(172.21.101.34)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 139872415; Mon, 09 Jan 2023 15:48:47 +0800 Received: from mtkmbs13n1.mediatek.inc (172.21.101.193) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.3; Mon, 9 Jan 2023 15:48:46 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkmbs13n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.15 via Frontend Transport; Mon, 9 Jan 2023 15:48:46 +0800 From: Miles Chen To: CC: , , , , Subject: Re: [PATCH] arm64: asm: vdso: gettimeofday: export common variables Date: Mon, 9 Jan 2023 15:48:46 +0800 Message-ID: <20230109074846.23138-1-miles.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Catalin, >On Mon, Oct 11, 2021 at 02:47:56PM +0200, Arnd Bergmann wrote: >> On Mon, Oct 11, 2021 at 12:03 PM Will Deacon wrote: >> > On Thu, Oct 07, 2021 at 09:57:54PM +0200, Anders Roxell wrote: >> > > When building the kernel with sparse enabled 'C=1' the following >> > > warnings can be seen: >> > > >> > > arch/arm64/kernel/vdso/vgettimeofday.c:9:5: warning: symbol '__kernel_clock_gettime' was not declared. Should it be static? >> > > arch/arm64/kernel/vdso/vgettimeofday.c:15:5: warning: symbol '__kernel_gettimeofday' was not declared. Should it be static? >> > > arch/arm64/kernel/vdso/vgettimeofday.c:21:5: warning: symbol '__kernel_clock_getres' was not declared. Should it be static? >> > > >> > > Rework so the variables are exported, since these variables are >> > > created and used in vdso/vgettimeofday.c, also used in vdso.lds.S. >> > >> > Hmm, these functions are part of the vDSO and shouldn't be called from the >> > kernel, so I don't think it makes sense to add prototypes for them to a >> > kernel header, to be honest. >> >> It's a recurring problem, and I have recommended this method to Anders as >> I don't see any of the alternatives as better. >> >> The thing is that both sparse (with make C=1) and gcc/clang (with make W=1) >> warn about missing prototypes, and this catches a lot of real bugs. I hope >> that we can eventually get to the point of enabling the warning by default for >> all files, but that means we need a declaration for each global function and >> variable. > >I don't think there's anything in the asm/vdso/gettimeofday.h that is >required by the kernel. However, it gets dragged in via the datapage.h. >If I got it right, something like this should avoid it and we can >include the prototypes: > > I tested your patch and I still got the same sparse error. So I was thinking that we should keep Anders' arm64/include/asm/vdso/gettimeofday.h part. The following patch works for me (tested with C=1, ARCH=arm64 defconfig) diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h index 764d13e2916c..d751aa6af7bf 100644 --- a/arch/arm64/include/asm/vdso/gettimeofday.h +++ b/arch/arm64/include/asm/vdso/gettimeofday.h @@ -14,6 +14,13 @@ #define VDSO_HAS_CLOCK_GETRES 1 +extern int __kernel_clock_gettime(clockid_t clock, + struct __kernel_timespec *ts); +extern int __kernel_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz); +extern int __kernel_clock_getres(clockid_t clock_id, + struct __kernel_timespec *res); + static __always_inline int gettimeofday_fallback(struct __kernel_old_timeval *_tv, struct timezone *_tz) diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h index 73eb622e7663..a8d26d7d042d 100644 --- a/include/vdso/datapage.h +++ b/include/vdso/datapage.h @@ -121,22 +121,6 @@ struct vdso_data { extern struct vdso_data _vdso_data[CS_BASES] __attribute__((visibility("hidden"))); extern struct vdso_data _timens_data[CS_BASES] __attribute__((visibility("hidden"))); -/* - * The generic vDSO implementation requires that gettimeofday.h - * provides: - * - __arch_get_vdso_data(): to get the vdso datapage. - * - __arch_get_hw_counter(): to get the hw counter based on the - * clock_mode. - * - gettimeofday_fallback(): fallback for gettimeofday. - * - clock_gettime_fallback(): fallback for clock_gettime. - * - clock_getres_fallback(): fallback for clock_getres. - */ -#ifdef ENABLE_COMPAT_VDSO -#include -#else -#include -#endif /* ENABLE_COMPAT_VDSO */ - #endif /* !__ASSEMBLY__ */ #endif /* __VDSO_DATAPAGE_H */ diff --git a/include/vdso/gettimeofday.h b/include/vdso/gettimeofday.h new file mode 100644 index 000000000000..0270da504fe3 --- /dev/null +++ b/include/vdso/gettimeofday.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * The generic vDSO implementation requires that gettimeofday.h + * provides: + * - __arch_get_vdso_data(): to get the vdso datapage. + * - __arch_get_hw_counter(): to get the hw counter based on the + * clock_mode. + * - gettimeofday_fallback(): fallback for gettimeofday. + * - clock_gettime_fallback(): fallback for clock_gettime. + * - clock_getres_fallback(): fallback for clock_getres. + */ +#ifdef ENABLE_COMPAT_VDSO +#include +#else +#include +#endif /* ENABLE_COMPAT_VDSO */ diff --git a/include/vdso/helpers.h b/include/vdso/helpers.h index 9a2af9fca45e..cb7a456323e3 100644 --- a/include/vdso/helpers.h +++ b/include/vdso/helpers.h @@ -6,6 +6,8 @@ #include +#include + static __always_inline u32 vdso_read_begin(const struct vdso_data *vd) { u32 seq; diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index ce2f69552003..8c1786ae59d8 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -3,6 +3,7 @@ * Generic userspace implementations of gettimeofday() and similar. */ #include +#include #include #ifndef vdso_calc_delta thanks, Miles -- 2.18.0