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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA826C54EBE for ; Mon, 9 Jan 2023 10:38:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233883AbjAIKih (ORCPT ); Mon, 9 Jan 2023 05:38:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234296AbjAIKie (ORCPT ); Mon, 9 Jan 2023 05:38:34 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE23C17891 for ; Mon, 9 Jan 2023 02:38:33 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8C23AB80D6E for ; Mon, 9 Jan 2023 10:38:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B580EC433D2; Mon, 9 Jan 2023 10:38:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673260711; bh=W9pelfN1J1+NxrDkdq4AjUwjRODipX6fJSEy+FDAMw4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cdx2hd5Pdg+qd8lzFyHayLkvjikk7emJFNd9OGraLCjqYMoxK2tux4zc9pOP/8RXz yvGZVR5C/YuV7YF19ANF4yFFmE7z8uYuOB6OXKNbh4byVMAMFdy5syz+/b1KmVTIzj xT4Qk4Oal6BemeJSQd2H1W5V8apTEgWS7rrVFgyHnITc7TZfECoTzF9iPXCvwXGf8T LdlBMwnHbz01cPSfnClXb1+vjnHVk45AhcvQzRoVraGw3wG/YXAQ9EKjI6sdX5ttZk nRPZIRP9y27lF0dKz2RsZnh3P29WVBXIyaBUf+8t6HarRz8SINdmD8OqOHoR3tDvwB gQuU42LJ4bazQ== Date: Mon, 9 Jan 2023 10:38:25 +0000 From: Lee Jones To: Ard Biesheuvel Cc: linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, will@kernel.org, catalin.marinas@arm.com, Mark Rutland Subject: Re: [PATCH v3 0/2] efi: Follow-up fixes for EFI runtime stack Message-ID: References: <20230106174703.1883495-1-ardb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230106174703.1883495-1-ardb@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On Fri, 06 Jan 2023, Ard Biesheuvel wrote: > Commit ff7a167961d1b ("arm64: efi: Execute runtime services from a > dedicated stack") introduced a dedicated stack for EFI runtime services, > in an attempt to make the execution of EFI runtime services more robust, > given that they execute at the same privilege level as the kernel. > > However, this stack needs to be declared to the stacktrace machinery, > which is careful not to walk the stack when it leads into memory regions > that are not known to be allocated for stack use. > > Also, given that the ACPI code may invoke the low-level EFI runtime call > wrapper without using the dedicated kernel thread and workqueue, we > should take this into account when trying to gracefully handle > synchronous exceptions. > > Changes since v2: > - clear efi_rt_stack_top[-1] from asm code, and use READ_ONCE() to read > its value when not holding the spinlock, to ensure that all accesses > are safe under concurrency; > - add Mark's ack to patch #2 > > Cc: Mark Rutland > Cc: Lee Jones > > Ard Biesheuvel (2): > arm64: efi: Avoid workqueue to check whether EFI runtime is live > arm64: efi: Account for the EFI runtime stack in stack unwinder Should either / both of these be routed to Stable? If so, we should probably Cc: them. > arch/arm64/include/asm/efi.h | 9 +++++++++ > arch/arm64/include/asm/stacktrace.h | 15 +++++++++++++++ > arch/arm64/kernel/efi-rt-wrapper.S | 6 ++++++ > arch/arm64/kernel/efi.c | 3 ++- > arch/arm64/kernel/stacktrace.c | 12 ++++++++++++ > 5 files changed, 44 insertions(+), 1 deletion(-) > > -- > 2.39.0 > -- Lee Jones [李琼斯] 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 32CB5C54EBD for ; Mon, 9 Jan 2023 10:39:46 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UKswTWMXHcBKPWAj+O12bEQfSbx2qTEU202SWWWvQ5I=; b=kIYHiAO+87eeRd OJHdCedUrldHwmrJgeM3jzzJuy7OtIflf38ig3H25tfipplbqE55ZZCYfPCsxp8hdaORoUgcyN/Uy PsJm2TtyKUoiCey3xOPU2XWRgrqqxD2Tjmh2rtrLLYfXqnVOCUa/EXm+mKvIbwEJQp6EvN3kC6NgH tCzWM48z4PKH4fMQdQAnxCf1G8o3aGLGVK5DKik/p/JGw5KzuxvJzNVT4GNflzXGRYjKK0EuGaqC2 rdnVlYXh6BB89JROtrn/XeVRIHQc6pOtOlXMBPYt4u9qmLOkrd0J+rsLev75mmOgydYpjlRaYmfSD ThBzQVA1yS4Du2KfyVMw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pEpYE-000rGc-EZ; Mon, 09 Jan 2023 10:38:46 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pEpY3-000rDh-5K for linux-arm-kernel@lists.infradead.org; Mon, 09 Jan 2023 10:38:43 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 67C40B80D67; Mon, 9 Jan 2023 10:38:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B580EC433D2; Mon, 9 Jan 2023 10:38:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673260711; bh=W9pelfN1J1+NxrDkdq4AjUwjRODipX6fJSEy+FDAMw4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cdx2hd5Pdg+qd8lzFyHayLkvjikk7emJFNd9OGraLCjqYMoxK2tux4zc9pOP/8RXz yvGZVR5C/YuV7YF19ANF4yFFmE7z8uYuOB6OXKNbh4byVMAMFdy5syz+/b1KmVTIzj xT4Qk4Oal6BemeJSQd2H1W5V8apTEgWS7rrVFgyHnITc7TZfECoTzF9iPXCvwXGf8T LdlBMwnHbz01cPSfnClXb1+vjnHVk45AhcvQzRoVraGw3wG/YXAQ9EKjI6sdX5ttZk nRPZIRP9y27lF0dKz2RsZnh3P29WVBXIyaBUf+8t6HarRz8SINdmD8OqOHoR3tDvwB gQuU42LJ4bazQ== Date: Mon, 9 Jan 2023 10:38:25 +0000 From: Lee Jones To: Ard Biesheuvel Cc: linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, will@kernel.org, catalin.marinas@arm.com, Mark Rutland Subject: Re: [PATCH v3 0/2] efi: Follow-up fixes for EFI runtime stack Message-ID: References: <20230106174703.1883495-1-ardb@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230106174703.1883495-1-ardb@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230109_023835_440831_289FE680 X-CRM114-Status: GOOD ( 21.04 ) 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: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gRnJpLCAwNiBKYW4gMjAyMywgQXJkIEJpZXNoZXV2ZWwgd3JvdGU6Cgo+IENvbW1pdCBmZjdh MTY3OTYxZDFiICgiYXJtNjQ6IGVmaTogRXhlY3V0ZSBydW50aW1lIHNlcnZpY2VzIGZyb20gYQo+ IGRlZGljYXRlZCBzdGFjayIpIGludHJvZHVjZWQgYSBkZWRpY2F0ZWQgc3RhY2sgZm9yIEVGSSBy dW50aW1lIHNlcnZpY2VzLAo+IGluIGFuIGF0dGVtcHQgdG8gbWFrZSB0aGUgZXhlY3V0aW9uIG9m IEVGSSBydW50aW1lIHNlcnZpY2VzIG1vcmUgcm9idXN0LAo+IGdpdmVuIHRoYXQgdGhleSBleGVj dXRlIGF0IHRoZSBzYW1lIHByaXZpbGVnZSBsZXZlbCBhcyB0aGUga2VybmVsLgo+IAo+IEhvd2V2 ZXIsIHRoaXMgc3RhY2sgbmVlZHMgdG8gYmUgZGVjbGFyZWQgdG8gdGhlIHN0YWNrdHJhY2UgbWFj aGluZXJ5LAo+IHdoaWNoIGlzIGNhcmVmdWwgbm90IHRvIHdhbGsgdGhlIHN0YWNrIHdoZW4gaXQg bGVhZHMgaW50byBtZW1vcnkgcmVnaW9ucwo+IHRoYXQgYXJlIG5vdCBrbm93biB0byBiZSBhbGxv Y2F0ZWQgZm9yIHN0YWNrIHVzZS4KPiAKPiBBbHNvLCBnaXZlbiB0aGF0IHRoZSBBQ1BJIGNvZGUg bWF5IGludm9rZSB0aGUgbG93LWxldmVsIEVGSSBydW50aW1lIGNhbGwKPiB3cmFwcGVyIHdpdGhv dXQgdXNpbmcgdGhlIGRlZGljYXRlZCBrZXJuZWwgdGhyZWFkIGFuZCB3b3JrcXVldWUsIHdlCj4g c2hvdWxkIHRha2UgdGhpcyBpbnRvIGFjY291bnQgd2hlbiB0cnlpbmcgdG8gZ3JhY2VmdWxseSBo YW5kbGUKPiBzeW5jaHJvbm91cyBleGNlcHRpb25zLgo+IAo+IENoYW5nZXMgc2luY2UgdjI6Cj4g LSBjbGVhciBlZmlfcnRfc3RhY2tfdG9wWy0xXSBmcm9tIGFzbSBjb2RlLCBhbmQgdXNlIFJFQURf T05DRSgpIHRvIHJlYWQKPiAgIGl0cyB2YWx1ZSB3aGVuIG5vdCBob2xkaW5nIHRoZSBzcGlubG9j aywgdG8gZW5zdXJlIHRoYXQgYWxsIGFjY2Vzc2VzCj4gICBhcmUgc2FmZSB1bmRlciBjb25jdXJy ZW5jeTsKPiAtIGFkZCBNYXJrJ3MgYWNrIHRvIHBhdGNoICMyCj4gCj4gQ2M6IE1hcmsgUnV0bGFu ZCA8bWFyay5ydXRsYW5kQGFybS5jb20+Cj4gQ2M6IExlZSBKb25lcyA8bGVlQGtlcm5lbC5vcmc+ Cj4gCj4gQXJkIEJpZXNoZXV2ZWwgKDIpOgo+ICAgYXJtNjQ6IGVmaTogQXZvaWQgd29ya3F1ZXVl IHRvIGNoZWNrIHdoZXRoZXIgRUZJIHJ1bnRpbWUgaXMgbGl2ZQo+ICAgYXJtNjQ6IGVmaTogQWNj b3VudCBmb3IgdGhlIEVGSSBydW50aW1lIHN0YWNrIGluIHN0YWNrIHVud2luZGVyCgpTaG91bGQg ZWl0aGVyIC8gYm90aCBvZiB0aGVzZSBiZSByb3V0ZWQgdG8gU3RhYmxlPwoKSWYgc28sIHdlIHNo b3VsZCBwcm9iYWJseSBDYzogdGhlbS4KCj4gIGFyY2gvYXJtNjQvaW5jbHVkZS9hc20vZWZpLmgg ICAgICAgIHwgIDkgKysrKysrKysrCj4gIGFyY2gvYXJtNjQvaW5jbHVkZS9hc20vc3RhY2t0cmFj ZS5oIHwgMTUgKysrKysrKysrKysrKysrCj4gIGFyY2gvYXJtNjQva2VybmVsL2VmaS1ydC13cmFw cGVyLlMgIHwgIDYgKysrKysrCj4gIGFyY2gvYXJtNjQva2VybmVsL2VmaS5jICAgICAgICAgICAg IHwgIDMgKystCj4gIGFyY2gvYXJtNjQva2VybmVsL3N0YWNrdHJhY2UuYyAgICAgIHwgMTIgKysr KysrKysrKysrCj4gIDUgZmlsZXMgY2hhbmdlZCwgNDQgaW5zZXJ0aW9ucygrKSwgMSBkZWxldGlv bigtKQo+IAo+IC0tIAo+IDIuMzkuMAo+IAoKLS0gCkxlZSBKb25lcyBb5p2O55C85pavXQoKX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KbGludXgtYXJtLWtl cm5lbCBtYWlsaW5nIGxpc3QKbGludXgtYXJtLWtlcm5lbEBsaXN0cy5pbmZyYWRlYWQub3JnCmh0 dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtYXJtLWtlcm5l bAo=