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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C100FFF885A for ; Tue, 28 Apr 2026 08:13:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6NilECp0m2FUAOg9cioK7uduTaZS/ORavn8koLfI5Eg=; b=ixd6s4/wZZ7irmbxXa8eW1zmM+ SCDsTEx2UcxuF2POL465q8wqEhtSwBEtOYR8sOlZDXTOKgfdV2abtzRCptYTiKYsf2pxtedxbjXhg RKQS4vpsSg7qA2EThQc4ZnTu85hd7WIWb+Jo6WjhqbLx3fAjy+LNPufxvFZ7Wfv3WRPkAQPKLm7uz YE3MzqNzuuiO2H+IM7ewZX14eg6S05po3G0gmhFpnkjRKVsHtq29UaZ5t36dFs3vNkD5EBk5RRxHG X/0n3zrLLxWxgWt2Qeb4c1by6ad35US3W8FpVMr1d/gZSybI/2wrLGiS0vZ9XUBxd6hqNYbGNyjul BK4LhyQg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHdZB-00000000rOy-0ubn; Tue, 28 Apr 2026 08:13:13 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHdZ9-00000000rOi-41UZ for linux-arm-kernel@bombadil.infradead.org; Tue, 28 Apr 2026 08:13:11 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=6NilECp0m2FUAOg9cioK7uduTaZS/ORavn8koLfI5Eg=; b=k4KfIK0ITOixVALBXHoYtDhJKs 6j641Q59Lf3O0PVWJk0atTPTd5JM7gGutG4Wc9/KZ4oSNL9fHuWyBGU8A136Dbl3irdF+YK44Lq58 FQkTbxxtUyi+4hpTCoOrPwxVwhbdR3SNd33wA2sn0s6uJdgYNAIMSEa8CGMTN2VoZDOFiwE/BzHoT bij4WqgQkRtacxLbYaaIrtCTbq/SbHW6XOsU5bQkZTZVX1zw2Zz1cO+hG1b5iQwXjUV3jaGJQKPmS lW3VgvP8PdW67KFp1F2z+6TzxjeeIOkmU4Z4dGWIcHKV14FYHReRm/8yqnDSl2aGicM4aQ/J3EyO7 X3n8Wd3g==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHdZ7-00000002NAr-33r0; Tue, 28 Apr 2026 08:13:10 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id D832D301CEB; Tue, 28 Apr 2026 10:13:08 +0200 (CEST) Date: Tue, 28 Apr 2026 10:13:08 +0200 From: Peter Zijlstra To: Thomas Gleixner Cc: Mathias Stearn , Dmitry Vyukov , Jinjie Ruan , linux-man@vger.kernel.org, Mark Rutland , Mathieu Desnoyers , Catalin Marinas , Will Deacon , Boqun Feng , "Paul E. McKenney" , Chris Kennelly , regressions@lists.linux.dev, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Ingo Molnar , Blake Oler , Florian Weimer , Rich Felker , Matthew Wilcox , Greg Kroah-Hartman , Linus Torvalds Subject: Re: [REGRESSION] rseq: refactoring in v6.19 broke everyone on arm64 and tcmalloc everywhere Message-ID: <20260428081308.GK3102924@noisy.programming.kicks-ass.net> References: <87ik9i0xlj.ffs@tglx> <87a4ut1njh.ffs@tglx> <87v7dgzbo7.ffs@tglx> <20260424150318.GE641209@noisy.programming.kicks-ass.net> <87se8kywhb.ffs@tglx> <87jyttz8cf.ffs@tglx> <20260428073938.GH3126523@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260428073938.GH3126523@noisy.programming.kicks-ass.net> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Apr 28, 2026 at 09:39:38AM +0200, Peter Zijlstra wrote: > > + return IS_ALIGNED((unsigned long)rseq, rseq_alloc_align()) && > > + rseq_len >= offsetof(struct rseq, end); > > +} > > Given we really only differentiate between ORIG_RSEQ_SIZE (32) and > sizeof(struct rseq), perhaps we should also add something like: > > if (rseq_len != sizeof(struct rseq)) > return false; > Wakeup juice, I need more wakeup juice :-) Its there, except written weirdly with that offsetof thing.