From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 B2444442114; Wed, 8 Jul 2026 14:09:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783519754; cv=none; b=pNQTE2LnWTb/thw3LlB5ODWIM0htL4aPK7RQdBM9szKgKPOIT4IIbQdiJ7ghEHEMO2hXDWJgRE2Dxe6Bt7+5zHa+s7ZVX5Drt308FI+7QDEzIbxBuzz3SnQIGUYQMotnN2VAl2QRV/a3Yxe38ca5dbJlA3WHnVkWr5NRe/0NoCo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783519754; c=relaxed/simple; bh=M1ph9XIqBC2fH+vP/HCbgBGMTjNgNaNhQndf8/PAhgc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jkeXlL+79KIw5bntKWlTTHPxWP0Mjg3fhPYNwfIHwGTEUQT7JcCzZLkqvvuWhV2M+zs4NnLWK2nT5EUB+iJ5vEHGSL2PM3WiwYy+cPc9ozP3J8vga2SfQU8uaCkoD3yTFLaRVDnah5vXzYj5mPFzws3AE0p3BLMC4QectWORV6c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=it1AC++S; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="it1AC++S" Received: from pps.filterd (m0360083.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 668CIYUk3243532; Wed, 8 Jul 2026 14:08:11 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=GEjSUR f+Oc47/KvAIRxIcmtLYIml26GEKQF9rwik+OM=; b=it1AC++SiBIAqAcqiPq93t pjWkqrK605Ig+Fp+n6nyGY4MvyzTT6PVTI1d/QjJkcXBDkutS+kGZr/rMVLnsK20 83Nf2F5IgcwxVpzlmCJx3J59iuz/ImvWoCglnlVb9KpAsAqGRC2XDl/YWK1+5eOp +BnXqWxI/05TkIjjB9RzIa/RPLO8v5Ce+RKot2wZXGgt+unxuZnOVkY/2cx6ABEy pDND8FrIXRdIESKhXHId05Wgv68LATT9kkNZiQhQN6JLtMmcnTyzSWeq/RWgrKZd 4CNMJriX/u2aMZKyKFDeU3Xj3NqrL5l0d7VK7IFQCg9CIUGyvE7hFtSo7NlZk0Qw == Received: from ppma12.dal12v.mail.ibm.com (dc.9e.1632.ip4.static.sl-reverse.com [50.22.158.220]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4f6sp3vt4n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Jul 2026 14:08:10 +0000 (GMT) Received: from pps.filterd (ppma12.dal12v.mail.ibm.com [127.0.0.1]) by ppma12.dal12v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 668E4aiX000987; Wed, 8 Jul 2026 14:08:09 GMT Received: from smtprelay02.fra02v.mail.ibm.com ([9.218.2.226]) by ppma12.dal12v.mail.ibm.com (PPS) with ESMTPS id 4f7cgq8hub-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Jul 2026 14:08:09 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay02.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 668E87B552953472 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 8 Jul 2026 14:08:07 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5893220043; Wed, 8 Jul 2026 14:08:07 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 31CB520040; Wed, 8 Jul 2026 14:07:52 +0000 (GMT) Received: from [9.39.26.208] (unknown [9.39.26.208]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 8 Jul 2026 14:07:51 +0000 (GMT) Message-ID: <771d3150-7650-4ba6-b9d7-31a534f72cb5@linux.ibm.com> Date: Wed, 8 Jul 2026 19:37:51 +0530 Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [patch 01/18] powerpc: Move stack randomization after syscall_enter_from_user_mode() To: Thomas Gleixner , LKML Cc: Peter Zijlstra , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Kees Cook , Huacai Chen , loongarch@lists.linux.dev, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.org, Sven Schnelle , linux-s390@vger.kernel.org, x86@kernel.org, Mark Rutland , Jinjie Ruan , Andy Lutomirski , Oleg Nesterov , Richard Henderson , Russell King , Catalin Marinas , Guo Ren , Geert Uytterhoeven , Thomas Bogendoerfer , Helge Deller , Yoshinori Sato , Richard Weinberger , Chris Zankel , linux-arm-kernel@lists.infradead.org, linux-alpha@vger.kernel.org, linux-csky@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-sh@vger.kernel.org, linux-um@lists.infradead.org, Arnd Bergmann , Vineet Gupta , Will Deacon , Brian Cain , Michal Simek , Dinh Nguyen , "David S. Miller" , Andreas Larsson , linux-snps-arc@lists.infradead.org, linux-hexagon@vger.kernel.org, linux-openrisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, =?UTF-8?Q?Michal_Such=C3=A1nek?= , Jonathan Corbet , linux-doc@vger.kernel.org References: <20260707181957.433213175@kernel.org> <20260707190253.718191130@kernel.org> Content-Language: en-US From: Shrikanth Hegde In-Reply-To: <20260707190253.718191130@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Authority-Analysis: v=2.4 cv=KsJ9H2WN c=1 sm=1 tr=0 ts=6a4e59cb cx=c_pps a=bLidbwmWQ0KltjZqbj+ezA==:117 a=bLidbwmWQ0KltjZqbj+ezA==:17 a=IkcTkHD0fZMA:10 a=RAioF0-LDSMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=iQ6ETzBq9ecOQQE5vZCe:22 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=voM4FWlXAAAA:8 a=xoOMMzrzzHNEA0Jk9MYA:9 a=QEXdDO2ut3YA:10 a=IC2XNlieTeVoXbcui8wp:22 X-Proofpoint-Spam-Info: AW1haW4tMjYwNzA4MDEzNSBTYWx0ZWRfX3Hbrj21CCLzB kKSW8jXH6Bj74UUfNzioqmwVCV/ijDVvhJAjSPEr0PRBP7f/C8rZNu60kYcZr5VFMnqEWqfDA++ inZSpN3ruIS55U0sAZiMr1mp3yETXqg= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzA4MDEzNSBTYWx0ZWRfX1zZjIJAFUCrC DZZFHPLhsL8y5odyoK2G1FgYpxRt932tRoGDWK0fyKR4ICWQTR7y9CixTwoRlTEsJgHxYdDsxW/ vDCytNNTBf9qGopcuoTa/AfoIYP5/zKMOESsc5h8MkN4K+Uf4AdxEGyFCI5+vOxHPIbB8IqmeJm pofTRmoVVtdakQlcUwa/5iQWPHLRHFh3nnXP7i2wdhEwKU50t4+I1IxbYK74aJOGz40WRB4Y+V4 4L8Sbqh1GTuOEjLQb44e8SVXpvqwnYBDql+ViuMKMw7GgSmmOYeHOKcPR0lJvuu+XVbWRZ1EUzc 6crZl+xqk34xyqm/WMIBKetDHnyOG4hsMvqdfd6LFN/EzEGxxsXwZFa2vrz4uXcEoEG8vRy8hAQ jQT68kRhg96HNn0D/8F1334ciC2LdYUUMBojPYYvDfcCxB6zftVE1+6IswOt2cm6NCMaXOgtD9o i6zmvswRSv/7ugcSyPw== X-Proofpoint-ORIG-GUID: -jmj0fPWFB_5RGym_5okOoW04BYgxv97 X-Proofpoint-GUID: UewskUPBCDVeXb9KcNrW_7wrTfTPl4fV X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-07-08_02,2026-07-08_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 malwarescore=0 spamscore=0 adultscore=0 clxscore=1015 suspectscore=0 lowpriorityscore=0 priorityscore=1501 bulkscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607080135 On 7/8/26 12:35 AM, Thomas Gleixner wrote: > add_random_kstack_offset() is invoked before syscall_enter_from_user_mode() > establishes state. That's wrong because add_random_kstack_offset() calls > into instrumentable code. Thanks for fixing that. > > Move it after syscall_enter_from_user_mode() to ensure that state is > correctly established. > > Signed-off-by: Thomas Gleixner > Cc: Michael Ellerman > Cc: Shrikanth Hegde > Cc: linuxppc-dev@lists.ozlabs.org > --- > arch/powerpc/kernel/syscall.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/arch/powerpc/kernel/syscall.c > +++ b/arch/powerpc/kernel/syscall.c > @@ -19,8 +19,8 @@ notrace long system_call_exception(struc > long ret; > syscall_fn f; > > - add_random_kstack_offset(); > r0 = syscall_enter_from_user_mode(regs, r0); > + add_random_kstack_offset(); > > if (unlikely(r0 >= NR_syscalls)) { > if (unlikely(trap_is_unsupported_scv(regs))) { > Reviewed-by: Shrikanth Hegde