From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fhigh-b2-smtp.messagingengine.com (fhigh-b2-smtp.messagingengine.com [202.12.124.153]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D8CD91E3DF7 for ; Tue, 17 Dec 2024 10:41:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.153 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734432079; cv=none; b=IAmNQS2ZPJ4doHscbUIQv2Iowute2NzZV6LNzdRDwN6+chRS8GdaSERFr0NpFdFFTXTnQoRZg2jlbiEpvGSqMb6OpThfkTWektCJQEGW8fm7LQfBCcX8Oj64v7vvo2qIo7LRKwW1kVU2Xa03YOj0SImi4aWTDWVC9u2XCK/AkoM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734432079; c=relaxed/simple; bh=JbB3DqItbZT8U1Ti7EGXc9z4W3+l8Q4TSVtADO0Z+Vw=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=c/cPEfCo50GgLgDwptvSRVhmwiuZdUxTgemnQCkVsBw007SsVkgVpdLT9AX6QoysVWXydbYuZF6OFLClnGyQOIIBtvuQVpcPtuI67UdZAaXB8+jf7XgoTNwBeHy9QRx1UkLvCQuMYSdgDkEo0G9zb26/OZT7A3kkFTlgefqTqhA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de; spf=pass smtp.mailfrom=arndb.de; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b=CP1evQie; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=GKV/m6CW; arc=none smtp.client-ip=202.12.124.153 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arndb.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b="CP1evQie"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="GKV/m6CW" Received: from phl-compute-10.internal (phl-compute-10.phl.internal [10.202.2.50]) by mailfhigh.stl.internal (Postfix) with ESMTP id B72512540196; Tue, 17 Dec 2024 05:41:16 -0500 (EST) Received: from phl-imap-11 ([10.202.2.101]) by phl-compute-10.internal (MEProxy); Tue, 17 Dec 2024 05:41:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm1; t=1734432076; x=1734518476; bh=nQbsDzhovafTMtuYVtRUcRqyLmRPs0PvON3BGL9CJZc=; b= CP1evQieaAhzpxAQEr2oVADIwswbkPIpNQbFWxdsMPhTcMc3l5epQbk+i9LOEUhq 2E0IYGgowfxad4in6U9eEvFlSMWIH0e1tR3Tf3Fb1+t6pz+tgrmZZNHYmdq2PNYF 1+8yDyo4f1Q2TbIxKw+wkvFZpLehKPxwxaPxdgl8RUFuVZj7/dVXJhuZQI/MF2iA gLYeyaNFR47jTC2GznD5I8vWZs7wTJz5gyJskQPsZcyuykUWoQj7uhyNtG7tDVwI gWCWA2hm3HbxL6DFkEIsTP7Hqpx0eRlwUh+eZEoOGQTQlzMQnU/YcnzKTecdRYri nnAI8KElUeKRLrI03SjP4g== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t=1734432076; x= 1734518476; bh=nQbsDzhovafTMtuYVtRUcRqyLmRPs0PvON3BGL9CJZc=; b=G KV/m6CWTtocajWP4BepishXIYIQeX3nRnmLvqKHYqWa7X+nSoHZfdB0ODAs6+VvZ TXSwBfRsm1gC4Ez+TyJSAG/Yy0M0zZ5UWZv2MCPOuhmAd9MYXMQcF3N65/Lowcwi E2BQmQhR7GXr0kuLbb9kIzJnXL0crH+aoJQZUBFE6KYHOhM9oEcEPEjduB8/u/yL +PfhPxW0hSZiQpoyybXDrySz2X9JA9nKdFqY8OJy8tsbFqyZjLS5zvK8ZX+lh6hJ mxE1SdEgD/arIEtdhuIAy7agvUHNWQxsaZGjrW36NA89/CefN7pn35nJ+SU6Bwtm 0rZIKJD6fs3EI+HX6vn5g== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefuddrleehgddulecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpggftfghnshhusghstghrihgsvgdpuffr tefokffrpgfnqfghnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnth hsucdlqddutddtmdenucfjughrpefoggffhffvvefkjghfufgtgfesthejredtredttden ucfhrhhomhepfdetrhhnugcuuegvrhhgmhgrnhhnfdcuoegrrhhnugesrghrnhgusgdrug gvqeenucggtffrrghtthgvrhhnpeekvdefgfeigedtuddujeduueekleefuedvtdehfefh jefhvddtkedufeekjefhkeenucffohhmrghinhepghhouggsohhlthdrohhrghenucevlh hushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegrrhhnugesrghr nhgusgdruggvpdhnsggprhgtphhtthhopeegpdhmohguvgepshhmthhpohhuthdprhgtph htthhopehpvghtvghriiesihhnfhhrrgguvggrugdrohhrghdprhgtphhtthhopehjphho ihhmsghovgeskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepgiekieeskhgvrhhnvghlrd horhhgpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghl rdhorhhg X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id 5D8642220072; Tue, 17 Dec 2024 05:41:16 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Tue, 17 Dec 2024 11:37:54 +0100 From: "Arnd Bergmann" To: "Josh Poimboeuf" , "Peter Zijlstra" Cc: x86@kernel.org, linux-kernel@vger.kernel.org Message-Id: <485d1139-0c09-4d56-b076-e3e0f131b738@app.fastmail.com> In-Reply-To: <710349fd-08df-444f-b8c6-86b1249810df@app.fastmail.com> References: <33f3a0a3-a929-4584-af81-6e020671d428@app.fastmail.com> <710349fd-08df-444f-b8c6-86b1249810df@app.fastmail.com> Subject: Re: "relocation to !ENDBR" objtool warnings Content-Type: text/plain Content-Transfer-Encoding: 7bit On Tue, Dec 17, 2024, at 10:09, Arnd Bergmann wrote: > On Tue, Dec 17, 2024, at 09:54, Arnd Bergmann wrote: >> >> 00000000000000f0 : >> f0: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1) >> f7: 00 00 00 00 >> fb: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) >> 100: f3 0f 1e fa endbr64 > > > I had one more look at the assembler file created by gcc and found > that this is a 16-byte nop: > > .align 16 > .globl stpcpy > .type stpcpy, @function > stpcpy: > .p2align 5 > endbr64 ... > > No idea why it got inserted here, or why it only shows up in these > two functions. Having a nop before the endbr is a compiler bug, right? I confirmed that this is only a problem on gcc-14.2, both gcc-14.1 and gcc trunk (15.0 I assume) are fine according to the compiler explorer: https://godbolt.org/z/9xf7Ph8GT Arnd