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[23.128.96.34]) by mx.google.com with ESMTPS id s140-20020a632c92000000b00578a56a39dbsi28752941pgs.409.2023.10.02.14.58.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Oct 2023 14:58:16 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=h8XkvrNM; dkim=neutral (no key) header.i=@linutronix.de header.s=2020e header.b=FBt+lmTW; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by howler.vger.email (Postfix) with ESMTP id B9EB680248C1; Mon, 2 Oct 2023 12:02:02 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at howler.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238554AbjJBTB4 (ORCPT + 18 others); Mon, 2 Oct 2023 15:01:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229696AbjJBTBy (ORCPT ); Mon, 2 Oct 2023 15:01:54 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6EA75B3; Mon, 2 Oct 2023 12:01:50 -0700 (PDT) Date: Mon, 02 Oct 2023 19:01:47 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1696273308; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=J5JVuozAWsvYoCCJ91LTdlldPKoE+8ohqohFARoyNwo=; b=h8XkvrNMlxZ8jPuDgfBEDxnScR1jtOn/WjRkutzFG66wB332lkBYS9UDLLZY9qkVCaQuEW LCAZyoy6NS8W5aSj9Mpkn5TadkNUBMEZPqQi3nbPb5cE8puRUAuOHoScyGIpgK1Flhnw8s u7/jKst+/84DlX84OLmm/EkLwi5blkih55DCqJQ2wFZsiQ4MFvR5vyF1oWW5z0zmQUhTz3 TsMQAl3YgE11/34SEbjwO7IXLrUMPpG5DbkAmsvZlYp/w3hVXQmQyjrLVSyOOAeCsdFzJS fv5t42qTFZ69vfgPUkhOYxuVpoO7S+W064hRESIyKN9pj9olQHVa7WRpf3soYw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1696273308; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=J5JVuozAWsvYoCCJ91LTdlldPKoE+8ohqohFARoyNwo=; b=FBt+lmTWi0C4QAfLx2kJaieFps1629b+dnsCPXex9mOE87mDvw0BR2K2eF2AxAAMy6tHBc Qj05AMx56uWwhYBQ== From: "tip-bot2 for Kir Kolyshkin" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] sched/headers: Move 'struct sched_param' out of uapi, to work around glibc/musl breakage Cc: Kir Kolyshkin , Ingo Molnar , Linus Torvalds , Peter Zijlstra , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20230808030357.1213829-1-kolyshkin@gmail.com> References: <20230808030357.1213829-1-kolyshkin@gmail.com> MIME-Version: 1.0 Message-ID: <169627330795.3135.16650166898816781742.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (howler.vger.email [0.0.0.0]); Mon, 02 Oct 2023 12:02:02 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1778682583137951146 X-GMAIL-MSGID: 1778682583137951146 The following commit has been merged into the sched/core branch of tip: Commit-ID: d844fe65f0957024c3e1b0bf2a0615246184d9bc Gitweb: https://git.kernel.org/tip/d844fe65f0957024c3e1b0bf2a0615246184d9bc Author: Kir Kolyshkin AuthorDate: Mon, 07 Aug 2023 20:03:57 -07:00 Committer: Ingo Molnar CommitterDate: Mon, 02 Oct 2023 20:48:16 +02:00 sched/headers: Move 'struct sched_param' out of uapi, to work around glibc/musl breakage Both glibc and musl define 'struct sched_param' in sched.h, while kernel has it in uapi/linux/sched/types.h, making it cumbersome to use sched_getattr(2) or sched_setattr(2) from userspace. For example, something like this: #include #include struct sched_attr sa; will result in "error: redefinition of ‘struct sched_param’" (note the code doesn't need sched_param at all -- it needs struct sched_attr plus some stuff from sched.h). The situation is, glibc is not going to provide a wrapper for sched_{get,set}attr, thus the need to include linux/sched_types.h directly, which leads to the above problem. Thus, the userspace is left with a few sub-par choices when it wants to use e.g. sched_setattr(2), such as maintaining a copy of struct sched_attr definition, or using some other ugly tricks. OTOH, 'struct sched_param' is well known, defined in POSIX, and it won't be ever changed (as that would break backward compatibility). So, while 'struct sched_param' is indeed part of the kernel uapi, exposing it the way it's done now creates an issue, and hiding it (like this patch does) fixes that issue, hopefully without creating another one: common userspace software rely on libc headers, and as for "special" software (like libc), it looks like glibc and musl do not rely on kernel headers for 'struct sched_param' definition (but let's Cc their mailing lists in case it's otherwise). The alternative to this patch would be to move struct sched_attr to, say, linux/sched.h, or linux/sched/attr.h (the new file). Oh, and here is the previous attempt to fix the issue: https://lore.kernel.org/all/20200528135552.GA87103@google.com/ While I support Linus arguments, the issue is still here and needs to be fixed. [ mingo: Linus is right, this shouldn't be needed - but on the other hand I agree that this header is not really helpful to user-space as-is. So let's pretend that is only about sched_attr, and call this commit a workaround for user-space breakage that it in reality is ... Also, remove the Fixes tag. ] Signed-off-by: Kir Kolyshkin Signed-off-by: Ingo Molnar Cc: Linus Torvalds Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20230808030357.1213829-1-kolyshkin@gmail.com --- include/linux/sched.h | 5 ++++- include/uapi/linux/sched/types.h | 4 ---- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index dc37ae7..e4235bb 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -63,7 +63,6 @@ struct robust_list_head; struct root_domain; struct rq; struct sched_attr; -struct sched_param; struct seq_file; struct sighand_struct; struct signal_struct; @@ -370,6 +369,10 @@ extern struct root_domain def_root_domain; extern struct mutex sched_domains_mutex; #endif +struct sched_param { + int sched_priority; +}; + struct sched_info { #ifdef CONFIG_SCHED_INFO /* Cumulative counters: */ diff --git a/include/uapi/linux/sched/types.h b/include/uapi/linux/sched/types.h index f2c4589..9066238 100644 --- a/include/uapi/linux/sched/types.h +++ b/include/uapi/linux/sched/types.h @@ -4,10 +4,6 @@ #include -struct sched_param { - int sched_priority; -}; - #define SCHED_ATTR_SIZE_VER0 48 /* sizeof first published struct */ #define SCHED_ATTR_SIZE_VER1 56 /* add: util_{min,max} */