From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 B774B3FCB37 for ; Wed, 10 Jun 2026 12:37:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781095050; cv=none; b=kIzWn2ZOZWJg/wOob4oo4Fkm3RkYg3TNJwNKPqjb5EUJrS1KWefAW7a6amFRp8xu3U1LAwFxSLmVGqnGzsPdLBX0N4OexbHvkj+Dni7Xc/SBY4neQcbGQhdkzt+5tunHfGdz1rBKCu0zs157wvsXkmYEzcNJXY4gBhjUapDit+k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781095050; c=relaxed/simple; bh=XmqGuY34YcrL4UE1wwK1Wq3TEBrRs6w8GH352Zaym7w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=n3FAiyuDjmgIWN8paRmD3SbwGQc7Wmku+SE4SLCPJgRwVKLuVqkdup7BNb2aL++NrHofq5ljp/xtJXfnJ4NfU3Oa7hVAIurLM63vFIfuqfeBoof9vWH5efeRQGC94VmN6r7kv8PIaDuCMFlmhqThfNoXNArmCl9O5L7J4S4WasE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hWKqrVRw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hWKqrVRw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F6C51F00893; Wed, 10 Jun 2026 12:37:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781095048; bh=eKd0rR0vYdw7TNYYE0+R6v5uU/CkiKwhomGx2lqxDSE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=hWKqrVRwze2Xz+0rY8JQIX0p2Yox6UtVDfHF0lZwyPLxCGK94vGqaM6gA5HGNXiJ4 QTnbzaYmJcJGKE3YNCbejqJZVjWNLSCRbTQa1xYW8Nf231TVH82wxpWzGbkiSnVWNT zkHQ9GdhUcdCNn5RzuoZ3l2GSp7gEq0lV0NPaK0Bhzgrn8/v77z/P2euPRkYgMaOhJ 2JazSTZq/ulXrTSjT1mrQoj9MXNct7F494dxeCyjzZ1kZ/a0Mli8umzDmdtydrY12z ENHXQyWdMe6T/WUg0mHeDUOEEuV7ldm1NkBFMrUkdwBv2/G7EgMLbQefpVr2nQUrOP 7PHcVchNPKA/Q== Date: Wed, 10 Jun 2026 13:37:22 +0100 From: Will Deacon To: Mathias Stearn Cc: Jinjie Ruan , Mark Rutland , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Peter Zijlstra , Thomas Gleixner , ckennelly@google.com, dvyukov@google.com, linux-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com Subject: Re: [PATCHv2] arm64/entry: Fix arm64-specific rseq brokenness Message-ID: References: <20260508142023.3268622-1-mark.rutland@arm.com> <54ffcf73-dfc5-417c-b9d5-6dee551f8d39@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Jun 09, 2026 at 02:04:23PM +0200, Mathias Stearn wrote: > Did the arm64-specific fix to rseq not get backportted to 7.0? We just > ran our test suite against 7.0.10 which has the other rseq fixes and > everything was fine on x86_64, but arm64 was frequently segfaulting. > > I had an AI agent look into this and it reported: > """ > The fix (commits b9eac6a9d93c, 82f572449cfe, 99428157dcf3, > 411c1cf43039) first appeared in v7.1-rc1 and will be included in > v7.1.0. > > The three commits backported to linux-7.0.y: > - 663121edad54 — "rseq: Revert to historical performance killing behaviour" > - d242126fd21a — "rseq: Implement read only ABI enforcement for > optimized RSEQ V2 mode" > - fb742945d61a — "rseq: Reenable performance optimizations conditionally" > > The arm64-specific fix (411c1cf43039 "arm64/entry: Fix arm64-specific > rseq brokenness") was not backported to any stable branch — it will > only appear in v7.1.0. > """ > > Is it possible to get 411c1cf43039 backported to 7.0 or was it omitted > intentionally? You can send a backport to the stable maintainers: https://docs.kernel.org/process/stable-kernel-rules.html#procedure-for-submitting-patches-to-the-stable-tree (see option 3) Will