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 X-Spam-Level: X-Spam-Status: No, score=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9106AC433EF for ; Mon, 13 Sep 2021 16:21:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 734DD60295 for ; Mon, 13 Sep 2021 16:21:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236244AbhIMQXL (ORCPT ); Mon, 13 Sep 2021 12:23:11 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:37834 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235632AbhIMQXH (ORCPT ); Mon, 13 Sep 2021 12:23:07 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]:36934) by out03.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mPoiL-003rDB-KW; Mon, 13 Sep 2021 10:21:49 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:47520 helo=email.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mPoiJ-00GFz6-JY; Mon, 13 Sep 2021 10:21:48 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Christophe Leroy Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , hch@infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org References: <1718f38859d5366f82d5bef531f255cedf537b5d.1631537060.git.christophe.leroy@csgroup.eu> <2b179deba4fd4ec0868cdc48a0230dfa3aa5a22f.1631537060.git.christophe.leroy@csgroup.eu> <87h7eopixa.fsf@disp2133> Date: Mon, 13 Sep 2021 11:21:41 -0500 In-Reply-To: <87h7eopixa.fsf@disp2133> (Eric W. Biederman's message of "Mon, 13 Sep 2021 10:57:37 -0500") Message-ID: <87y280o38q.fsf@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1mPoiJ-00GFz6-JY;;;mid=<87y280o38q.fsf@disp2133>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19YOxK9unwbVjxKnnW7IzmHNswDYE8PXPw= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH RESEND v3 6/6] powerpc/signal: Use unsafe_copy_siginfo_to_user() X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ebiederm@xmission.com (Eric W. Biederman) writes: > Christophe Leroy writes: > >> Use unsafe_copy_siginfo_to_user() in order to do the copy >> within the user access block. >> >> On an mpc 8321 (book3s/32) the improvment is about 5% on a process >> sending a signal to itself. If you can't make function calls from an unsafe macro there is another way to handle this that doesn't require everything to be inline. >From a safety perspective it is probably even a better approach. Eric diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 0608581967f0..1b30bb78b863 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -205,6 +205,12 @@ struct sigframe { int abigap[56]; }; +#ifdef CONFIG_PPC64 +# define user_siginfo_t compat_siginfo_t +#else +# define user_siginfo_t siginfo_t +#endif + /* * When we have rt signals to deliver, we set up on the * user stack, going down from the original stack pointer: @@ -217,11 +223,7 @@ struct sigframe { * */ struct rt_sigframe { -#ifdef CONFIG_PPC64 - compat_siginfo_t info; -#else - struct siginfo info; -#endif + user_siginfo_t info; struct ucontext uc; #ifdef CONFIG_PPC_TRANSACTIONAL_MEM struct ucontext uc_transact; @@ -712,7 +714,7 @@ static long restore_tm_user_regs(struct pt_regs *regs, struct mcontext __user *s #ifdef CONFIG_PPC64 -#define copy_siginfo_to_user copy_siginfo_to_user32 +#define copy_siginfo_to_external copy_siginfo_to_external32 #endif /* CONFIG_PPC64 */ @@ -731,6 +733,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs = tsk->thread.regs; /* Save the thread's msr before get_tm_stackpointer() changes it */ unsigned long msr = regs->msr; + user_siginfo_t uinfo; /* Set up Signal Frame */ frame = get_sigframe(ksig, tsk, sizeof(*frame), 1); @@ -743,6 +746,8 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, else prepare_save_user_regs(1); + copy_siginfo_to_external(&uinfo, &ksig->info); + if (!user_access_begin(frame, sizeof(*frame))) goto badframe; @@ -778,12 +783,10 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset, asm("dcbst %y0; sync; icbi %y0; sync" :: "Z" (mctx->mc_pad[0])); } unsafe_put_sigset_t(&frame->uc.uc_sigmask, oldset, failed); + unsafe_copy_to_user(&frame->info, &uinfo, failed); user_access_end(); - if (copy_siginfo_to_user(&frame->info, &ksig->info)) - goto badframe; - regs->link = tramp; #ifdef CONFIG_PPC_FPU_REGS Eric