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 23E712F8E98; Tue, 30 Jun 2026 15:10:43 +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=1782832244; cv=none; b=fifNcf0Ahu2Wdfuqw5wfa1rVH/cbrOT6EPc8pKOT3ikpG9OgXYx3Eci2k2oTiatnMrPlpBObw8rhkZJ4T9ODqryt0XvjKZTWifQhi5QsoHXVZcP9svvXLhEO74qBMPbAYu0Rh1yPEov6TivVGNFVs6dO7BOWggrAJaqKnsc+8Vw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782832244; c=relaxed/simple; bh=IJN8GCa75tXNOusahS2SS6FLKbmYA/g4TDhS1/Bnexs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=r91qeY0AnnUge0EOT1SB9Wr5BI2XbOEaLwfU39mY4jbdhY8peRdjTx8mdv2CBdn9CRvNHwLXcGGsnknue9870ifMQSWUdLuKH93hFY26RD1luVphqVpBU1SS1kd/ZX8b9hvgs4GVHww5R6NQxLOEDb1DWx9nRzZvbotP/OF7fz0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foss.arm.com; spf=pass smtp.mailfrom=foss.arm.com; dkim=pass (1024-bit key) header.d=foss.arm.com header.i=@foss.arm.com header.b=N4rTq1+X; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=foss.arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=foss.arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=foss.arm.com header.i=@foss.arm.com header.b="N4rTq1+X" 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 2599E2F27; Tue, 30 Jun 2026 08:10:38 -0700 (PDT) Received: from [10.211.55.246] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EEB233F66F; Tue, 30 Jun 2026 08:10:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=foss.arm.com; s=main; t=1782832242; bh=IJN8GCa75tXNOusahS2SS6FLKbmYA/g4TDhS1/Bnexs=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=N4rTq1+XJ5MZWK5epRjs6xByi4TTG70VNWthnJlC8jJwI278e2E1e/fm+cNZq3Pft L/NAG87p9H2OJSj9kmTzGAcN40zWWlYJEdxtMCi/744noD9aXOZHYMM0wOHhVMN+iZ WtxMPaMyFplX6WXbGMItHU3P+/VcJG1TikDZ00+Q= Message-ID: <9e3ca6bd-bd05-40b3-9b6f-85552009537a@foss.arm.com> Date: Mon, 29 Jun 2026 12:09:27 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] selftest/x86: test ARCH_SHSTK_UNLOCK To: "Edgecombe, Rick P" , "x86@kernel.org" , "dave.hansen@linux.intel.com" , "shuah@kernel.org" , "mingo@redhat.com" , "bp@alien8.de" , "tglx@kernel.org" , "hpa@zytor.com" Cc: "linux-kernel@vger.kernel.org" , "linux-kselftest@vger.kernel.org" References: <20260615195156.257950-1-bill.roberts@arm.com> <20260615195156.257950-2-bill.roberts@arm.com> <67e700c8bed2e082efaf68de33ee2c46d16033f3.camel@intel.com> Content-Language: en-US From: Bill Roberts In-Reply-To: <67e700c8bed2e082efaf68de33ee2c46d16033f3.camel@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/29/26 4:46 PM, Edgecombe, Rick P wrote: > On Mon, 2026-06-15 at 14:51 -0500, Bill Roberts wrote: >> One should not be able to use ARCH_SHSTK_UNLOCK via arch_prctl to twiddle >> feature bits, test that this is the case. >> >> Signed-off-by: Bill Roberts >> --- >> tools/testing/selftests/x86/test_shadow_stack.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/tools/testing/selftests/x86/test_shadow_stack.c b/tools/testing/selftests/x86/test_shadow_stack.c >> index 21af54d5f4ea..82a5fefa9df5 100644 >> --- a/tools/testing/selftests/x86/test_shadow_stack.c >> +++ b/tools/testing/selftests/x86/test_shadow_stack.c >> @@ -979,6 +979,14 @@ int main(int argc, char *argv[]) >> { >> int ret = 0; >> >> + /* test that we can't use unlock to set shadow stack */ >> + if (!ARCH_PRCTL(ARCH_SHSTK_UNLOCK, ARCH_SHSTK_SHSTK)) { >> + printf("[SKIP]\tCould enable Shadow stack via UNLOCK\n"); >> + return 1; >> + } > More generally, we should not be able to use ARCH_SHSTK_UNLOCK here. Can we make > the comment generic and not checking for a specific bug? Because it does more > than that. Hey Rick, not really sure how I could make the git commit message and the comment more generic, as they seem really generic, can you please be more specific or give me a blurb you're looking for here? > >> + >> + printf("[OK]\tCouldn't enable Shadow stack via UNLOCK\n"); >> + >> if (ARCH_PRCTL(ARCH_SHSTK_ENABLE, ARCH_SHSTK_SHSTK)) { >> printf("[SKIP]\tCould not enable Shadow stack\n"); >> return 1;