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 3A4D4C44501 for ; Thu, 9 Jul 2026 02:47:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:CC:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=kv8IL35UvaNtNSUMIaLZRkq9pv8ulEOI7gP7hRHl8KE=; b=HDbPETqnVklYAHgyV8IvWqIIJn IhqwtHjvk+PW9uBIFkiUm9dCL06RhIGDbXe6dfOAdHCwpIYfLPC5r+E1o35/qj5kgif+2xEE8Fjid 4nFm8T+WH+wcWY0N8SIXtFRiNXFbStVrYpkCRyG6mFHW7NRElUKrnQJ+lw/odCd53JJW0a4qX5tPp Bd/+XfsvSINFfHwYTgM0snmzU3XRtGmGCoVlcfUixinB+hVkIWqTv+73Kmxo5ANPOCgiScgdrO00L 4aL8flJDRLwI34ZRKLhXvCaCpdGR4/IzGb9lK/tgyU/BGzBUTMzTA8Wb10xVgRDu9kjan/DS8trmk 0TjxSjsA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whemx-00000000rfd-30JN; Thu, 09 Jul 2026 02:46:59 +0000 Received: from canpmsgout03.his.huawei.com ([113.46.200.218]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1whemu-00000000reu-34Te; Thu, 09 Jul 2026 02:46:58 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=kv8IL35UvaNtNSUMIaLZRkq9pv8ulEOI7gP7hRHl8KE=; b=On7r31a+HPKtqYCFGKCz4xqmSm+Xp8N2LTAjxPpcAv4gJhYIcSVayrLTG5iBdCMzOqUT02IrL XwrnDkN0nCnpOlz6679vIblC0MGBbYdgb5gp/4+6hf1F9Yi4y2WjjW/XV4WC9/v5qLynobzorwW 7UPpvG0wGL8s6DBSn4wLi4k= Received: from mail.maildlp.com (unknown [172.19.162.144]) by canpmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4gwfJv5NHxzpTBG; Thu, 9 Jul 2026 10:38:07 +0800 (CST) Received: from dggpemf500011.china.huawei.com (unknown [7.185.36.131]) by mail.maildlp.com (Postfix) with ESMTPS id 38F8540538; Thu, 9 Jul 2026 10:46:49 +0800 (CST) Received: from [10.67.109.254] (10.67.109.254) by dggpemf500011.china.huawei.com (7.185.36.131) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 9 Jul 2026 10:46:46 +0800 Message-ID: <499eca86-8def-4044-8b69-8f290528e10f@huawei.com> Date: Thu, 9 Jul 2026 10:46:44 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [patch 07/18] s390/syscall: Use enter_from_user_mode_randomize_stack() To: Thomas Gleixner , LKML CC: Peter Zijlstra , Sven Schnelle , , Michael Ellerman , Shrikanth Hegde , , Kees Cook , Huacai Chen , , Paul Walmsley , Palmer Dabbelt , , , Mark Rutland , Andy Lutomirski , Oleg Nesterov , Richard Henderson , Russell King , Catalin Marinas , Guo Ren , Geert Uytterhoeven , Thomas Bogendoerfer , Helge Deller , Yoshinori Sato , Richard Weinberger , Chris Zankel , , , , , , , , , Arnd Bergmann , Vineet Gupta , Will Deacon , Brian Cain , Michal Simek , Dinh Nguyen , "David S. Miller" , Andreas Larsson , , , , , , =?UTF-8?Q?Michal_Such=C3=A1nek?= , Jonathan Corbet , References: <20260707181957.433213175@kernel.org> <20260707190254.030598804@kernel.org> From: Jinjie Ruan In-Reply-To: <20260707190254.030598804@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To dggpemf500011.china.huawei.com (7.185.36.131) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260708_194657_152984_3E3F81E3 X-CRM114-Status: GOOD ( 12.56 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On 7/8/2026 3:06 AM, Thomas Gleixner wrote: > 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); The #include can be removed. > + > regs->psw = get_lowcore()->svc_old_psw; > regs->int_code = get_lowcore()->svc_int_code; > update_timer_sys(); >