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 38A86C79FB7 for ; Wed, 9 Sep 2026 20:01:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2Q8UEBQNxTKPJ7uP+ulND/QmjJc29SNHMs8Adv4sbFc=; b=FC1HHjZ+zRXRah /q6HFfVWfgN+tjFbPmmxpl8vddIlIMcZZkMVnmDh33SZ5ON6CR22Zj6lh9YJWooiXTcge00CnXYTg Ek9TPjsIu3SXjxyjwn1odZMwbrGJLJUk9F0xrJ5Phn8JzMdN4k5isvj92aJYbzcLgZkWJ4x+vQBBw Hnu1M2scyjnOIAIHrDE1iMJwVGOAmrfY5zKR+HxNze9UYLpFLvFzJiORCyul4ZGyR2rVj4CxfZxd2 HBILQ6GcCvvhwMXzZthpBO/tsifs+hWC1ezMijHXEN5TSsRZlJObPdqbCEOfVhkRbIlaVvT6RxBHr jI63k5I8Nlf8LDV0F92Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4OTt-0000000CmIy-39uI; Wed, 09 Sep 2026 20:01:17 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4OTq-0000000CmHl-1Q5j; Wed, 09 Sep 2026 20:01:15 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AB42B1570; Wed, 9 Sep 2026 13:01:07 -0700 (PDT) Received: from [10.211.55.7] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BAF703F7B4; Wed, 9 Sep 2026 13:01:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=foss.arm.com; s=main; t=1788984071; bh=rNi5YhSEeETSE5FQBog3k1r0aviOJOf+s/njOtyxBZE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=HnL3iTWUzI5pHllYz6CCHmcPV3JTw+s6qzHZZToyX8cY0TBKM130vVtUdiL2JwN+G /8IMNBhLGf6IMvg5JAecf3/j2SujtIhDOIUmv1SnU6JOhvLB1iobKgEx/gCGbaofGy u6UNzBwtszGomEhOE5GTTi+QO1cB/EndPZx3QVr4= Message-ID: Date: Wed, 9 Sep 2026 15:01:10 -0500 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Shadow Stack Locking Semantics between arch's To: Mark Brown , "Edgecombe, Rick P" Cc: Jesse Huang , "linux-riscv@lists.infradead.org" , linux-arm-kernel@lists.infradead.org, "linux-kernel@vger.kernel.org" , linux-hardening@vger.kernel.org, linux-api@vger.kernel.org, dave.hansen@linux.intel.com, rick.p.edgecombe@intel.com, debug@rivosinc.com, andrew@sifive.com, kito.cheng@sifive.com References: <3bb672e0-7bc3-434f-904e-aa00394dd01f@foss.arm.com> <0ef9f4ab-4c9f-4089-bed3-f7726ec97804@foss.arm.com> <522bcf96-499c-491b-aaf0-34e6bbd42929@sirena.org.uk> Content-Language: en-US From: Bill Roberts In-Reply-To: <522bcf96-499c-491b-aaf0-34e6bbd42929@sirena.org.uk> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260909_130114_509692_A9B7A598 X-CRM114-Status: UNSURE ( 9.68 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Pj4+PiB1bnNpZ25lZCBsb25nIGxvY2tlZCA9IDB4MjsgLy8gS2VybmVsIFRhc2sgU3RhdGUgLT4g TE9DSyBXUklURQo+Pj4+IHVuc2lnbmVkIGxvbmcgY3VyX3ZhbCA9IDB4MzsgLy8gS2VybmVsIFRh c2sgU3RhdGUgLT4gV1JJVEUgYW5kIFNIQURPV1NUQUNLCj4+Pj4gRU5BQkxFRAo+Pj4+IHVuc2ln bmVkIGxvbmcgbmV3X3ZhbCA9IDB4MDsgLy8gVXNlcnNwYWNlIEZlYXR1cmUgQ2hhbmdlIHZpYSBz eXNjYWxsIC0+Cj4+Pj4gRElTQUJMRQo+Pj4+IHwgeDg2LTY0IHwgcmlzYy12IHwgYXJtNjQgfAo+ Pj4+IHwgLS0tLS0tLS0tLSB8IC0tLS0tLS0tIHwgLS0tLS0tLS0tIHwKPj4+PiB8IFdvcmtzwqAg fCBGYWlsc8KgIHwgRmFpbHPCoCDCoCDCoHwKPj4+IEkgd291bGQgbm90IGhhdmUgZXhwZWN0ZWQg dGhhdCBjb21iaW5hdGlvbiB0byB3b3JrIGF0IGFsbCB3aXRoIHRoZQo+Pj4gcHJjdGwoKSAoYXMg b3Bwb3NlZCB0byBhcmNoX3ByY3RsKCkpIGludGVyZmFjZSBUQkgsIGlmIHlvdSd2ZSBsb2NrZWQK Pj4+IHdyaXRlIG9uIHlvdSBzaG91bGRuJ3QgYmUgYWJsZSB0byBkaXNhYmxlIGl0LiAgVGhlIHJl YXNvbiB0aGF0IHdvcmtzIG9uCj4+PiB4ODYgYXQgdGhlIG1pbnV0ZSBpcyB0aGF0IGZvciB4ODYg eW91IGNhbiBvbmx5IGNoYW5nZSBvbmUgYml0IGF0IGEgdGltZQo+Pj4gc28gdGhlIG5ldyB2YWx1 ZSB3aGVuIGRpc2FibGluZyBpcyBlZmZlY3RpdmVseSAweDIsIG5vdCAweDAuCj4+IFllcywgdGhp cyBpcyBleGFjdGx5IHdoYXQgSSBhbSBwb2ludGluZyBvdXQuIEltcGxlbWVudGF0aW9uIGFzaWRl LCBpcyB0aGF0Cj4+IHRoZSBiZWhhdmlvciB3ZSB3YW50Pwo+IEl0IHNlZW1zIG1vcmUgaGVscGZ1 bCB0byBzdXBwb3J0IGNoYW5naW5nIG1vcmUgdGhhbiBvbmUgYml0IGF0IG9uY2UuCisgUmljayBp biAidG8iLCBJIHdhbnQgaGltIHRvIHdlaWdoIGluIGFzIHdlbGwuCgpJIHRoaW5rIHdlJ3JlIHN0 aWxsIG1pc2NvbW11bmljYXRpbmcuwqAgVGhlIGlzc3VlIGlzLCB0aGF0IGluIHRoZSBjdXJyZW50 CmludGVyZmFjZSBmb3IgeDg2IHZpYSBhcmNoX3ByY3RsLCB3aGljaCBpcyBvbmUgYml0IGF0IGEg dGltZSwgdGhlIGV4cGxpY2l0CmxvY2tpbmcgb2Ygd3JpdGUgY2FuIGJlIHVuZG9uZSB2aWEgdHVy bmluZyBvZmYgdGhlIHNoYWRvdyBzdGFjay4gU2hvdWxkCnRoYXQgc3VjY2VlZCwgb3Igc2hvdWxk IHRoYXQgZmFpbCBzaW5jZSBpdCBpbXBsaWNpdGx5IHR1cm5zIG9mZiB3cml0ZT8gClNob3VsZAp3 ZSBwcmVzZXJ2ZSB0aGF0IGFzIHdlIHBvcnQgdG8gcHJjdGw/IFNob3VsZCB3ZSBjaGFuZ2UgdGhh dCBpbiB4ODYKYXJjaF9wcmN0bCwgd2FzIHRoYXQgaW50ZW5kZWQ/CgoKX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KbGludXgtcmlzY3YgbWFpbGluZyBsaXN0 CmxpbnV4LXJpc2N2QGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5v cmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1yaXNjdgo=