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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 561A3C2BC73 for ; Wed, 4 Dec 2019 18:20:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1ACA9205ED for ; Wed, 4 Dec 2019 18:20:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575483605; bh=MDnrAbH5LjTTP8lBGz+TFmOLxt8p4m+wC3zXR8K4wA0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vUH5Q4HmsCsUJuIYGQLtkfu+4CuGLtgkFZ8IkG0eo9Ixh4lulfJgIxD3fSKEqlzsw mVzspz7WVZol9ok3T2cc6ZKqk0I+4twnDRJLUMKyq/bPGc9o+yipm7TJkm6uPdsC0a aTpEm6+j6UFDytleJQtNrv5TNaAhdeIcRW5ywdmo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731388AbfLDSUE (ORCPT ); Wed, 4 Dec 2019 13:20:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:33740 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730687AbfLDSI4 (ORCPT ); Wed, 4 Dec 2019 13:08:56 -0500 Received: from localhost (unknown [217.68.49.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EB77720675; Wed, 4 Dec 2019 18:08:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482935; bh=MDnrAbH5LjTTP8lBGz+TFmOLxt8p4m+wC3zXR8K4wA0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YS7a2FXUFFqNX7/8ogvSZJ06BVVilF7JJkI34rdmgv0ahYJsigYqdFCnXvuceHgyJ SF+dt4oi+41jmS+LBT+d8iNdK7wi6BwfwrYHFSyFn9cjZTZ+RYhLLE9eGjh0bGEu1T gZRBKVKxJsyXiHqAaC67qhSdXKZqljXUDK7wHPo8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "Peter Zijlstra (Intel)" Subject: [PATCH 4.14 187/209] futex: Move futex exit handling into futex code Date: Wed, 4 Dec 2019 18:56:39 +0100 Message-Id: <20191204175336.362734251@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204175321.609072813@linuxfoundation.org> References: <20191204175321.609072813@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner commit ba31c1a48538992316cc71ce94fa9cd3e7b427c0 upstream. The futex exit handling is #ifdeffed into mm_release() which is not pretty to begin with. But upcoming changes to address futex exit races need to add more functionality to this exit code. Split it out into a function, move it into futex code and make the various futex exit functions static. Preparatory only and no functional change. Folded build fix from Borislav. Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20191106224556.049705556@linutronix.de Signed-off-by: Greg Kroah-Hartman --- include/linux/compat.h | 2 -- include/linux/futex.h | 25 ++++++++++++++++--------- kernel/fork.c | 25 +++---------------------- kernel/futex.c | 33 +++++++++++++++++++++++++++++---- 4 files changed, 48 insertions(+), 37 deletions(-) --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -324,8 +324,6 @@ struct compat_kexec_segment; struct compat_mq_attr; struct compat_msgbuf; -extern void compat_exit_robust_list(struct task_struct *curr); - asmlinkage long compat_sys_set_robust_list(struct compat_robust_list_head __user *head, compat_size_t len); --- a/include/linux/futex.h +++ b/include/linux/futex.h @@ -2,7 +2,9 @@ #ifndef _LINUX_FUTEX_H #define _LINUX_FUTEX_H +#include #include + #include struct inode; @@ -51,19 +53,24 @@ union futex_key { #define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } } #ifdef CONFIG_FUTEX -extern void exit_robust_list(struct task_struct *curr); -#else -static inline void exit_robust_list(struct task_struct *curr) + +static inline void futex_init_task(struct task_struct *tsk) { -} + tsk->robust_list = NULL; +#ifdef CONFIG_COMPAT + tsk->compat_robust_list = NULL; #endif + INIT_LIST_HEAD(&tsk->pi_state_list); + tsk->pi_state_cache = NULL; +} -#ifdef CONFIG_FUTEX_PI -extern void exit_pi_state_list(struct task_struct *curr); +void futex_mm_release(struct task_struct *tsk); + +long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, + u32 __user *uaddr2, u32 val2, u32 val3); #else -static inline void exit_pi_state_list(struct task_struct *curr) -{ -} +static inline void futex_init_task(struct task_struct *tsk) { } +static inline void futex_mm_release(struct task_struct *tsk) { } #endif #endif --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1135,20 +1135,7 @@ static int wait_for_vfork_done(struct ta void mm_release(struct task_struct *tsk, struct mm_struct *mm) { /* Get rid of any futexes when releasing the mm */ -#ifdef CONFIG_FUTEX - if (unlikely(tsk->robust_list)) { - exit_robust_list(tsk); - tsk->robust_list = NULL; - } -#ifdef CONFIG_COMPAT - if (unlikely(tsk->compat_robust_list)) { - compat_exit_robust_list(tsk); - tsk->compat_robust_list = NULL; - } -#endif - if (unlikely(!list_empty(&tsk->pi_state_list))) - exit_pi_state_list(tsk); -#endif + futex_mm_release(tsk); uprobe_free_utask(tsk); @@ -1796,14 +1783,8 @@ static __latent_entropy struct task_stru #ifdef CONFIG_BLOCK p->plug = NULL; #endif -#ifdef CONFIG_FUTEX - p->robust_list = NULL; -#ifdef CONFIG_COMPAT - p->compat_robust_list = NULL; -#endif - INIT_LIST_HEAD(&p->pi_state_list); - p->pi_state_cache = NULL; -#endif + futex_init_task(p); + /* * sigaltstack should be cleared when sharing the same VM */ --- a/kernel/futex.c +++ b/kernel/futex.c @@ -341,6 +341,12 @@ static inline bool should_fail_futex(boo } #endif /* CONFIG_FAIL_FUTEX */ +#ifdef CONFIG_COMPAT +static void compat_exit_robust_list(struct task_struct *curr); +#else +static inline void compat_exit_robust_list(struct task_struct *curr) { } +#endif + static inline void futex_get_mm(union futex_key *key) { mmgrab(key->private.mm); @@ -890,7 +896,7 @@ static struct task_struct *futex_find_ge * Kernel cleans up PI-state, but userspace is likely hosed. * (Robust-futex cleanup is separate and might save the day for userspace.) */ -void exit_pi_state_list(struct task_struct *curr) +static void exit_pi_state_list(struct task_struct *curr) { struct list_head *next, *head = &curr->pi_state_list; struct futex_pi_state *pi_state; @@ -960,7 +966,8 @@ void exit_pi_state_list(struct task_stru } raw_spin_unlock_irq(&curr->pi_lock); } - +#else +static inline void exit_pi_state_list(struct task_struct *curr) { } #endif /* @@ -3611,7 +3618,7 @@ static inline int fetch_robust_entry(str * * We silently return on any sign of list-walking problem. */ -void exit_robust_list(struct task_struct *curr) +static void exit_robust_list(struct task_struct *curr) { struct robust_list_head __user *head = curr->robust_list; struct robust_list __user *entry, *next_entry, *pending; @@ -3676,6 +3683,24 @@ void exit_robust_list(struct task_struct } } +void futex_mm_release(struct task_struct *tsk) +{ + if (unlikely(tsk->robust_list)) { + exit_robust_list(tsk); + tsk->robust_list = NULL; + } + +#ifdef CONFIG_COMPAT + if (unlikely(tsk->compat_robust_list)) { + compat_exit_robust_list(tsk); + tsk->compat_robust_list = NULL; + } +#endif + + if (unlikely(!list_empty(&tsk->pi_state_list))) + exit_pi_state_list(tsk); +} + long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3) { @@ -3801,7 +3826,7 @@ static void __user *futex_uaddr(struct r * * We silently return on any sign of list-walking problem. */ -void compat_exit_robust_list(struct task_struct *curr) +static void compat_exit_robust_list(struct task_struct *curr) { struct compat_robust_list_head __user *head = curr->compat_robust_list; struct robust_list __user *entry, *next_entry, *pending;