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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 9A8B5C43331 for ; Sat, 28 Mar 2020 11:00:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CE3E20723 for ; Sat, 28 Mar 2020 11:00:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727795AbgC1LAf (ORCPT ); Sat, 28 Mar 2020 07:00:35 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:55535 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727067AbgC1LAE (ORCPT ); Sat, 28 Mar 2020 07:00:04 -0400 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jI9C4-0003bt-Pj; Sat, 28 Mar 2020 12:00:00 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 596451C0470; Sat, 28 Mar 2020 11:59:57 +0100 (CET) Date: Sat, 28 Mar 2020 10:59:57 -0000 From: "tip-bot2 for Al Viro" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/cleanups] x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame() Cc: Al Viro , x86 , LKML MIME-Version: 1.0 Message-ID: <158539319701.28353.6658289032826087569.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/cleanups branch of tip: Commit-ID: 39f16c1c0f14e9794545dbf6a64c909d5e16a2ea Gitweb: https://git.kernel.org/tip/39f16c1c0f14e9794545dbf6a64c909d5e16a2ea Author: Al Viro AuthorDate: Sat, 15 Feb 2020 18:39:17 -05:00 Committer: Al Viro CommitterDate: Thu, 19 Mar 2020 00:37:49 -04:00 x86: get rid of put_user_try in {ia32,x32}_setup_rt_frame() Straightforward, except for compat_save_altstack_ex() stuck in those. Replace that thing with an analogue that would use unsafe_put_user() instead of put_user_ex() (called unsafe_compat_save_altstack()) and be done with that... Signed-off-by: Al Viro --- arch/x86/ia32/ia32_signal.c | 50 ++++++++++++++++++------------------ arch/x86/kernel/signal.c | 33 +++++++++++++----------- include/linux/compat.h | 9 +++--- 3 files changed, 49 insertions(+), 43 deletions(-) diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c index af673ec..a96995a 100644 --- a/arch/x86/ia32/ia32_signal.c +++ b/arch/x86/ia32/ia32_signal.c @@ -326,35 +326,34 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig, frame = get_sigframe(ksig, regs, sizeof(*frame), &fpstate); - if (!access_ok(frame, sizeof(*frame))) + if (!user_access_begin(frame, sizeof(*frame))) return -EFAULT; - put_user_try { - put_user_ex(sig, &frame->sig); - put_user_ex(ptr_to_compat(&frame->info), &frame->pinfo); - put_user_ex(ptr_to_compat(&frame->uc), &frame->puc); + unsafe_put_user(sig, &frame->sig, Efault); + unsafe_put_user(ptr_to_compat(&frame->info), &frame->pinfo, Efault); + unsafe_put_user(ptr_to_compat(&frame->uc), &frame->puc, Efault); - /* Create the ucontext. */ - if (static_cpu_has(X86_FEATURE_XSAVE)) - put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags); - else - put_user_ex(0, &frame->uc.uc_flags); - put_user_ex(0, &frame->uc.uc_link); - compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); + /* Create the ucontext. */ + if (static_cpu_has(X86_FEATURE_XSAVE)) + unsafe_put_user(UC_FP_XSTATE, &frame->uc.uc_flags, Efault); + else + unsafe_put_user(0, &frame->uc.uc_flags, Efault); + unsafe_put_user(0, &frame->uc.uc_link, Efault); + unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault); - if (ksig->ka.sa.sa_flags & SA_RESTORER) - restorer = ksig->ka.sa.sa_restorer; - else - restorer = current->mm->context.vdso + - vdso_image_32.sym___kernel_rt_sigreturn; - put_user_ex(ptr_to_compat(restorer), &frame->pretcode); + if (ksig->ka.sa.sa_flags & SA_RESTORER) + restorer = ksig->ka.sa.sa_restorer; + else + restorer = current->mm->context.vdso + + vdso_image_32.sym___kernel_rt_sigreturn; + unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault); - /* - * Not actually used anymore, but left because some gdb - * versions need it. - */ - put_user_ex(*((u64 *)&code), (u64 __user *)frame->retcode); - } put_user_catch(err); + /* + * Not actually used anymore, but left because some gdb + * versions need it. + */ + unsafe_put_user(*((u64 *)&code), (u64 __user *)frame->retcode, Efault); + user_access_end(); err |= __copy_siginfo_to_user32(&frame->info, &ksig->info, false); err |= ia32_setup_sigcontext(&frame->uc.uc_mcontext, fpstate, @@ -380,4 +379,7 @@ int ia32_setup_rt_frame(int sig, struct ksignal *ksig, regs->ss = __USER32_DS; return 0; +Efault: + user_access_end(); + return -EFAULT; } diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 3b4ca48..29abad2 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -529,6 +529,9 @@ static int x32_setup_rt_frame(struct ksignal *ksig, int err = 0; void __user *fpstate = NULL; + if (!(ksig->ka.sa.sa_flags & SA_RESTORER)) + return -EFAULT; + frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate); if (!access_ok(frame, sizeof(*frame))) @@ -541,22 +544,17 @@ static int x32_setup_rt_frame(struct ksignal *ksig, uc_flags = frame_uc_flags(regs); - put_user_try { - /* Create the ucontext. */ - put_user_ex(uc_flags, &frame->uc.uc_flags); - put_user_ex(0, &frame->uc.uc_link); - compat_save_altstack_ex(&frame->uc.uc_stack, regs->sp); - put_user_ex(0, &frame->uc.uc__pad0); + if (!user_access_begin(frame, sizeof(*frame))) + return -EFAULT; - if (ksig->ka.sa.sa_flags & SA_RESTORER) { - restorer = ksig->ka.sa.sa_restorer; - } else { - /* could use a vstub here */ - restorer = NULL; - err |= -EFAULT; - } - put_user_ex(restorer, (unsigned long __user *)&frame->pretcode); - } put_user_catch(err); + /* Create the ucontext. */ + unsafe_put_user(uc_flags, &frame->uc.uc_flags, Efault); + unsafe_put_user(0, &frame->uc.uc_link, Efault); + unsafe_compat_save_altstack(&frame->uc.uc_stack, regs->sp, Efault); + unsafe_put_user(0, &frame->uc.uc__pad0, Efault); + restorer = ksig->ka.sa.sa_restorer; + unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault); + user_access_end(); err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, regs, set->sig[0]); @@ -582,6 +580,11 @@ static int x32_setup_rt_frame(struct ksignal *ksig, #endif /* CONFIG_X86_X32_ABI */ return 0; +#ifdef CONFIG_X86_X32_ABI +Efault: + user_access_end(); + return -EFAULT; +#endif } /* diff --git a/include/linux/compat.h b/include/linux/compat.h index 11083d8..224ecb4 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -483,12 +483,13 @@ extern void __user *compat_alloc_user_space(unsigned long len); int compat_restore_altstack(const compat_stack_t __user *uss); int __compat_save_altstack(compat_stack_t __user *, unsigned long); -#define compat_save_altstack_ex(uss, sp) do { \ +#define unsafe_compat_save_altstack(uss, sp, label) do { \ compat_stack_t __user *__uss = uss; \ struct task_struct *t = current; \ - put_user_ex(ptr_to_compat((void __user *)t->sas_ss_sp), &__uss->ss_sp); \ - put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \ - put_user_ex(t->sas_ss_size, &__uss->ss_size); \ + unsafe_put_user(ptr_to_compat((void __user *)t->sas_ss_sp), \ + &__uss->ss_sp, label); \ + unsafe_put_user(t->sas_ss_flags, &__uss->ss_flags, label); \ + unsafe_put_user(t->sas_ss_size, &__uss->ss_size, label); \ if (t->sas_ss_flags & SS_AUTODISARM) \ sas_ss_reset(t); \ } while (0);