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Wed, 08 Jul 2026 06:47:18 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (smtpav06.fra02v.mail.ibm.com [10.20.54.105]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 6686lGMb12976422 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 8 Jul 2026 06:47:16 GMT Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 84BCD20049; Wed, 8 Jul 2026 06:47:16 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 09F8D20040; Wed, 8 Jul 2026 06:47:16 +0000 (GMT) Received: from tuxmaker.linux.ibm.com (unknown [9.87.85.9]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTPS; Wed, 8 Jul 2026 06:47:15 +0000 (GMT) From: Sven Schnelle To: Thomas Gleixner Cc: LKML , Peter Zijlstra , linux-s390@vger.kernel.org, Michael Ellerman , Shrikanth Hegde , linuxppc-dev@lists.ozlabs.org, Kees Cook , Huacai Chen , loongarch@lists.linux.dev, Paul Walmsley , Palmer Dabbelt , linux-riscv@lists.infradead.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, Michal =?utf-8?Q?Such=C3=A1nek?= , Jonathan Corbet , linux-doc@vger.kernel.org Subject: Re: [patch 07/18] s390/syscall: Use enter_from_user_mode_randomize_stack() In-Reply-To: <20260707190254.030598804@kernel.org> References: <20260707181957.433213175@kernel.org> <20260707190254.030598804@kernel.org> Date: Wed, 08 Jul 2026 08:47:15 +0200 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-GUID: _L7edkq3BwnBWML6vUHeJ0rb1UtEu9CY X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzA4MDA1OCBTYWx0ZWRfXy3LHxWa7PIH+ 8urugSBuUbrtJi57OI87IYjkuqIiXGOGFK+88q8gEVOe7ERBr8TsrVGypKfNgvFuShFuK5wtiHj Zfx4VvtSTJG9XBXaO4MYfRBFI5rBkjhHVxI5WzazNrE1rEbw178sbd/cxA6Auww+KIhdddwtejJ 248bkWj12S+T6W3/mrf0LUiPVaXvbe32OIrqpAKj3jON8/Z4sW461FTCn6oauugcrSdf4ngCG9A Bjd+1hUZ81iR2MpsmkN2NtBwDJEQ+ZZf2mqghRWaGHeLLWTgm34cVk/vHeRpsZXUWFoQ1vYe+5X tbeYGoFzMCGLc9Qs5veIX8EC8xAv74iY/tqVUC8qt3d6EAvNIn5PzUFU1St8HVwn1XFeDmcRHny oEoQT+YS+miZuXlhWPhpBKCjMLxdBjJ9JOvWOsxszLTqO3yRBp31v2W/sChgHwIr1VV7XgJC5Cp eAQ5TpTCNimIS0W4vmA== X-Proofpoint-ORIG-GUID: pEfjwvvoAjoHowG9Dv6PDIJZE3RmcFmr X-Authority-Analysis: v=2.4 cv=FqQ1OWrq c=1 sm=1 tr=0 ts=6a4df278 cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=RAioF0-LDSMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=U7nrCbtTmkRpXpFmAIza:22 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=buEBMWGfP5CXRQqppmAA:9 X-Proofpoint-Spam-Info: AW1haW4tMjYwNzA4MDA1OCBTYWx0ZWRfX+R5HcxjXVv1w RVsRwLeD9F3N1eXzMOe+apX4IAesgta7GXGOixJqeU/NBHDn+tO8IhjIk+MU7dU+sY37T5/6W7w fxWFhXVc37deMYvOOlkRHjGNzgYwS7c= 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=2026-07-07_06,2026-07-06_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 clxscore=1011 malwarescore=0 lowpriorityscore=0 priorityscore=1501 bulkscore=0 suspectscore=0 spamscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607080058 Thomas Gleixner writes: > enter_from_user_mode_randomize_stack() replaces enter_from_user_mode() and > the subsequent invocation of add_random_kstack_offset_irqsoff(). > > As a bonus this avoids the overhead of get/put_cpu_var() in > add_random_kstack_offset(). > > No functional change. > > Signed-off-by: Thomas Gleixner > Cc: Sven Schnelle > Cc: linux-s390@vger.kernel.org > --- > arch/s390/kernel/syscall.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > --- a/arch/s390/kernel/syscall.c > +++ b/arch/s390/kernel/syscall.c > @@ -97,8 +97,8 @@ void noinstr __do_syscall(struct pt_regs > { > unsigned long nr; > > - enter_from_user_mode(regs); > - add_random_kstack_offset(); > + enter_from_user_mode_randomize_stack(regs); > + > regs->psw = get_lowcore()->svc_old_psw; > regs->int_code = get_lowcore()->svc_int_code; > update_timer_sys(); Reviewed-by: Sven Schnelle