From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id F389126AE4; Thu, 15 Aug 2024 16:31:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723739520; cv=none; b=gIM93NydbOVP9TkwhYCL+J2ZIhzCtQwN5Rwo12AGasw1G7+adZO/ZdU87v4YwJCyxRPtu7gBJuXKJktCf7AZ1P4GDssiwNQCDF/jwLNQcjPnCYp2OIxDimbJMQnGglbXAFlFmN6cnQjuvCud8eRiuHp3L9bCPRoRuS4513h7vtM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723739520; c=relaxed/simple; bh=v2DuIKDRYstSgnLhL+gVxytmZsWL98Xb4yRNcEnje9M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=EmBs3P8UeX6Ynvz6tmGfKlRoWOwX+dfow9XdM/KjKg8maFXlPzsHonlcAfMrQvQfFgY2PWP2jGEZ3FAx2h98l1ACxqzq25I8msCbEo9KK6PcHNf28EfKuzvn/hyz7YeR4MIRTbL2l88hpM6REXU/nP8EVR4pddzR4MLu1/jHN0M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 47EB014BF; Thu, 15 Aug 2024 09:32:24 -0700 (PDT) Received: from e133380.arm.com (e133380.arm.com [10.1.197.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 94A073F6A8; Thu, 15 Aug 2024 09:31:52 -0700 (PDT) Date: Thu, 15 Aug 2024 17:31:49 +0100 From: Dave Martin To: Mark Brown Cc: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , Kees Cook , "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , Ross Burton , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v10 23/40] arm64/signal: Set up and restore the GCS context for signal handlers Message-ID: References: <20240801-arm64-gcs-v10-0-699e2bd2190b@kernel.org> <20240801-arm64-gcs-v10-23-699e2bd2190b@kernel.org> <08932f6d-01ef-40e8-97d2-08f0d2016191@sirena.org.uk> <7fa96f26-5bf6-490f-8986-258033fbfe0e@sirena.org.uk> 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=us-ascii Content-Disposition: inline In-Reply-To: <7fa96f26-5bf6-490f-8986-258033fbfe0e@sirena.org.uk> On Thu, Aug 15, 2024 at 04:29:54PM +0100, Mark Brown wrote: > On Thu, Aug 15, 2024 at 04:11:56PM +0100, Dave Martin wrote: > > On Thu, Aug 15, 2024 at 03:45:45PM +0100, Mark Brown wrote: > > > On Thu, Aug 15, 2024 at 02:37:22PM +0100, Dave Martin wrote: > > > > > Is there a test for taking and returning from a signal on an alternate > > > > (main) stack, when a shadow stack is in use? Sounds like something > > > > that would be good to check if not. > > > > Not specifically for any of the architectures. > > > Can you see any reason why this shouldn't work? > > No, it's expected to work - I'm just not specifically aware of an > explicit test for it. Possibly some of the userspace bringup work > might've covered it? Any libc tests for altstack support should've > exercised it for example. That's true; if libc is built to use shadow stack, generic API tests ought to cover this. > > Maybe I'll hacking up a test if I get around to it, but don't take this > > as a promise! > > Thanks for your firm commitment! :P No problem... Cheers ---Dave