From patchwork Mon Jul 16 16:10:55 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 142047 Delivered-To: patch@linaro.org Received: by 2002:a2e:9754:0:0:0:0:0 with SMTP id f20-v6csp2604204ljj; Mon, 16 Jul 2018 09:12:10 -0700 (PDT) X-Google-Smtp-Source: AAOMgpf26biWypgt83TtV1BRYQuJYsUK0uJDWc120DPDSNqGPTpFupbI9Vp4rESaInPkc+Qe6852 X-Received: by 2002:a62:4308:: with SMTP id q8-v6mr18939551pfa.86.1531757530548; Mon, 16 Jul 2018 09:12:10 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531757530; cv=none; d=google.com; s=arc-20160816; b=OA9W/b2GN+713SsmqkDdCzu6xYn9CH7QBIye1xvFGs3hVwvFui1xW4/+YLrbtFc/tb 4mi2CNbkdG+K3qbTJFYS8w2r0vBpQ6chlVDvByBvv3UHADl4n/JArw/eGcPP0GzgcWLZ 1kERQe3LM+Uk/8jWR6flJPRmzSgDGqL282FW+3YES3gheUppZqeaJfuqPlOhJZYFjiZ8 j2VcnReMa0kRj7u5hT/V8jEHkd2mQZEjleF/si3bqI6KkbuuXqMbOP1x8BlH2hYRepZZ 3EvMCI3znGpKFw1MKDTif66xy1KTkM4+ieBd6rzYBbKRsdNcVrA/cXX5Itu/Y+LbtpIX nDsA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=+ebaR0Hlge/KfMdjinA/Vn4S6UmxI0FOFPhykmF9yPM=; b=UNKLqEw1qk3yGKpRKKv0tvDImeYh0wQCm5BWGgFOKadbEBdOtYkDUuun/DQwyUF0fm KPGE3BcVUpmtiQXcGuyV46IoNG+DM4+STDIl/T768hw6H+hYAUj0l2ieHoGdZCwndBxy zN379B8APR9zQaF6t2zBcz2wWvExzo2kCHEXaXMorEOp3uVTIVHGn1pQnDjoxTRcwjfl op62dp8b2oIJBqgoX3mj1icQQaROkHCIL7nFyLNRk91pF4nHELk+if6Mn9wo9I3lPLKk 2Xym9MFWkfAo3SsNpl6t4b+doRZCLXGjqRl70LvOpWsiqh5fZgNoY03kKmhiVs0Fl66O 3Q5g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of netdev-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=netdev-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id x18-v6si30410996pfh.84.2018.07.16.09.12.10; Mon, 16 Jul 2018 09:12:10 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of netdev-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of netdev-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=netdev-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731175AbeGPQkO (ORCPT + 10 others); Mon, 16 Jul 2018 12:40:14 -0400 Received: from mout.kundenserver.de ([212.227.126.133]:47067 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730621AbeGPQkO (ORCPT ); Mon, 16 Jul 2018 12:40:14 -0400 Received: from wuerfel.lan ([46.223.138.35]) by mrelayeu.kundenserver.de (mreue007 [212.227.15.129]) with ESMTPA (Nemesis) id 0MTrXg-1fWGQ30pdY-00QXBW; Mon, 16 Jul 2018 18:11:11 +0200 From: Arnd Bergmann To: tglx@linutronix.de Cc: y2038@lists.linaro.org, hch@infradead.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, libc-alpha@sourceware.org, albert.aribaud@3adev.fr, netdev@vger.kernel.org, viro@zeniv.linux.org.uk, peterz@infradead.org, dvhart@infradead.org, ebiederm@xmission.com, linux@dominikbrodowski.net, Arnd Bergmann Subject: [PATCH v2 09/17] y2038: futex: Move compat implementation into futex.c Date: Mon, 16 Jul 2018 18:10:55 +0200 Message-Id: <20180716161103.16239-10-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20180716161103.16239-1-arnd@arndb.de> References: <20180716161103.16239-1-arnd@arndb.de> X-Provags-ID: V03:K1:Kgt2Q5fIjXWoSGBaADrtlyO2LyhMoi3DhtgqeXhR7MiUTwSame3 xBlmJ9rBh4wHT01tc52GDpnWmLnFxZfWVYwnhUm+K3IBk6A6mP+ZFyDm4yI/DzezmVswM0H brBfleLR3SXyT/vqQiQYBh2CfdqMKg8iU2Q+1Wdj2hSUDRAropbidYSRSvXZeDGtK65A4Yc ahEswYU2o3xdWhnCQcYRw== X-UI-Out-Filterresults: notjunk:1; V01:K0:KKIs+bEbAF0=:+So299GCu/sS05kGhL+fdb J6nOS+lHm/i6voNu+vpRImn/43QkIN/YdN4BeGQAYwEQ2H5aAy3H8iaoucftNVJ164ARfeExt n6tOwVJ+aLOMsY8oNdFu7Ef7bpR9XJFvysS9WeqUMRKNxP/xFfHZBhMkLZgKxCCtN1K3kQkd0 Byki7bVUSJuq99+kBLMFLTLk0obCT+PMszPQv+3jmwO1fdviMqlmOT9X6Fi/z/lPMyZLrm6of Ohj4rOduLqk/dY4h4m1eLBoK6B9EmR7YYw4qYO29nEbBvfwyv/7i+aVV26Ebjo6EyfIjd2eUs EyX2/17QRgiZgZRX21ynXii4Wm/dhFc4/5N6osW7hSiAwBmNVQRqpGHeI+F9mFzdnYuPoLG86 zgbCYDB00+DobtmwAl95NAlHAGgfxWswXgtnCKQEnx+xigtE4AGHO4uMpBN4Zjv+kbX1hfH9c aXwKxQ97X0k2ocYH0Zb+LM3u19CIHvIrDUyyqEc9KNmdqB5EM+KXvpPhUtTb3Ie1vvUjnivMV JmSN112Of9cgQ2qJvvCDbj5iEU9TRHpv5tr14EBLQKns1wZlZT8MNKmthyKT+V0w0PIOQSCjq ggcHsAzfU49GE4ZiUw9/cYkZiKh1aG2nJj9jWKlbOn84x/l8mzM7zZeDWFMD5Uzrg7E3yGnuU jUdwNGZDjtRP08c5xrIEsaFdZcvP8ywcQDvIfDfwsFnwmNNP/iNO5K4WB1iX9Hc4uExs= Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We are going to share the compat_sys_futex() handler between 64-bit architectures and 32-bit architectures that need to deal with both 32-bit and 64-bit time_t, and this is easier if both entry points are in the same file. In fact, most other system call handlers do the same thing these days, so let's follow the trend here and merge all of futex_compat.c into futex.c. In the process, a few minor changes have to be done to make sure everything still makes sense: handle_futex_death() and futex_cmpxchg_enabled() become local symbol, and the compat version of the fetch_robust_entry() function gets renamed to compat_fetch_robust_entry() to avoid a symbol clash. This is intended as a purely cosmetic patch, no behavior should change. Signed-off-by: Arnd Bergmann --- Regardless of whether we rename all compat time calls or not, moving the compat futex code into the main file helps us clean up the implementation. --- include/linux/futex.h | 8 -- kernel/Makefile | 3 - kernel/futex.c | 195 +++++++++++++++++++++++++++++++++++++++++++++++- kernel/futex_compat.c | 202 -------------------------------------------------- 4 files changed, 192 insertions(+), 216 deletions(-) delete mode 100644 kernel/futex_compat.c -- 2.9.0 diff --git a/include/linux/futex.h b/include/linux/futex.h index 821ae502d3d8..ccaef0097785 100644 --- a/include/linux/futex.h +++ b/include/linux/futex.h @@ -9,9 +9,6 @@ struct inode; struct mm_struct; struct task_struct; -extern int -handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi); - /* * Futexes are matched on equal values of this key. * The key type depends on whether it's a shared or private mapping. @@ -55,11 +52,6 @@ extern void exit_robust_list(struct task_struct *curr); long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout, u32 __user *uaddr2, u32 val2, u32 val3); -#ifdef CONFIG_HAVE_FUTEX_CMPXCHG -#define futex_cmpxchg_enabled 1 -#else -extern int futex_cmpxchg_enabled; -#endif #else static inline void exit_robust_list(struct task_struct *curr) { diff --git a/kernel/Makefile b/kernel/Makefile index 7343b3a9bff0..8e40a6742d23 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -49,9 +49,6 @@ obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += time/ obj-$(CONFIG_FUTEX) += futex.o -ifeq ($(CONFIG_COMPAT),y) -obj-$(CONFIG_FUTEX) += futex_compat.o -endif obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o obj-$(CONFIG_SMP) += smp.o ifneq ($(CONFIG_SMP),y) diff --git a/kernel/futex.c b/kernel/futex.c index 1f450e092c74..e9013d1e65a1 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -44,6 +44,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include #include #include #include @@ -173,8 +174,10 @@ * double_lock_hb() and double_unlock_hb(), respectively. */ -#ifndef CONFIG_HAVE_FUTEX_CMPXCHG -int __read_mostly futex_cmpxchg_enabled; +#ifdef CONFIG_HAVE_FUTEX_CMPXCHG +#define futex_cmpxchg_enabled 1 +#else +static int __read_mostly futex_cmpxchg_enabled; #endif /* @@ -3360,7 +3363,7 @@ SYSCALL_DEFINE3(get_robust_list, int, pid, * Process a futex-list entry, check whether it's owned by the * dying task, and do notification if so: */ -int handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi) +static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr, int pi) { u32 uval, uninitialized_var(nval), mval; @@ -3587,6 +3590,192 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); } +#ifdef CONFIG_COMPAT +/* + * Fetch a robust-list pointer. Bit 0 signals PI futexes: + */ +static inline int +compat_fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry, + compat_uptr_t __user *head, unsigned int *pi) +{ + if (get_user(*uentry, head)) + return -EFAULT; + + *entry = compat_ptr((*uentry) & ~1); + *pi = (unsigned int)(*uentry) & 1; + + return 0; +} + +static void __user *futex_uaddr(struct robust_list __user *entry, + compat_long_t futex_offset) +{ + compat_uptr_t base = ptr_to_compat(entry); + void __user *uaddr = compat_ptr(base + futex_offset); + + return uaddr; +} + +/* + * Walk curr->robust_list (very carefully, it's a userspace list!) + * and mark any locks found there dead, and notify any waiters. + * + * We silently return on any sign of list-walking problem. + */ +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; + unsigned int limit = ROBUST_LIST_LIMIT, pi, pip; + unsigned int uninitialized_var(next_pi); + compat_uptr_t uentry, next_uentry, upending; + compat_long_t futex_offset; + int rc; + + if (!futex_cmpxchg_enabled) + return; + + /* + * Fetch the list head (which was registered earlier, via + * sys_set_robust_list()): + */ + if (compat_fetch_robust_entry(&uentry, &entry, &head->list.next, &pi)) + return; + /* + * Fetch the relative futex offset: + */ + if (get_user(futex_offset, &head->futex_offset)) + return; + /* + * Fetch any possibly pending lock-add first, and handle it + * if it exists: + */ + if (compat_fetch_robust_entry(&upending, &pending, + &head->list_op_pending, &pip)) + return; + + next_entry = NULL; /* avoid warning with gcc */ + while (entry != (struct robust_list __user *) &head->list) { + /* + * Fetch the next entry in the list before calling + * handle_futex_death: + */ + rc = compat_fetch_robust_entry(&next_uentry, &next_entry, + (compat_uptr_t __user *)&entry->next, &next_pi); + /* + * A pending lock might already be on the list, so + * dont process it twice: + */ + if (entry != pending) { + void __user *uaddr = futex_uaddr(entry, futex_offset); + + if (handle_futex_death(uaddr, curr, pi)) + return; + } + if (rc) + return; + uentry = next_uentry; + entry = next_entry; + pi = next_pi; + /* + * Avoid excessively long or circular lists: + */ + if (!--limit) + break; + + cond_resched(); + } + if (pending) { + void __user *uaddr = futex_uaddr(pending, futex_offset); + + handle_futex_death(uaddr, curr, pip); + } +} + +COMPAT_SYSCALL_DEFINE2(set_robust_list, + struct compat_robust_list_head __user *, head, + compat_size_t, len) +{ + if (!futex_cmpxchg_enabled) + return -ENOSYS; + + if (unlikely(len != sizeof(*head))) + return -EINVAL; + + current->compat_robust_list = head; + + return 0; +} + +COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid, + compat_uptr_t __user *, head_ptr, + compat_size_t __user *, len_ptr) +{ + struct compat_robust_list_head __user *head; + unsigned long ret; + struct task_struct *p; + + if (!futex_cmpxchg_enabled) + return -ENOSYS; + + rcu_read_lock(); + + ret = -ESRCH; + if (!pid) + p = current; + else { + p = find_task_by_vpid(pid); + if (!p) + goto err_unlock; + } + + ret = -EPERM; + if (!ptrace_may_access(p, PTRACE_MODE_READ_REALCREDS)) + goto err_unlock; + + head = p->compat_robust_list; + rcu_read_unlock(); + + if (put_user(sizeof(*head), len_ptr)) + return -EFAULT; + return put_user(ptr_to_compat(head), head_ptr); + +err_unlock: + rcu_read_unlock(); + + return ret; +} + +COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, + struct compat_timespec __user *, utime, u32 __user *, uaddr2, + u32, val3) +{ + struct timespec ts; + ktime_t t, *tp = NULL; + int val2 = 0; + int cmd = op & FUTEX_CMD_MASK; + + if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI || + cmd == FUTEX_WAIT_BITSET || + cmd == FUTEX_WAIT_REQUEUE_PI)) { + if (compat_get_timespec(&ts, utime)) + return -EFAULT; + if (!timespec_valid(&ts)) + return -EINVAL; + + t = timespec_to_ktime(ts); + if (cmd == FUTEX_WAIT) + t = ktime_add_safe(ktime_get(), t); + tp = &t; + } + if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE || + cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP) + val2 = (int) (unsigned long) utime; + + return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); +} +#endif /* CONFIG_COMPAT */ + static void __init futex_detect_cmpxchg(void) { #ifndef CONFIG_HAVE_FUTEX_CMPXCHG diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c deleted file mode 100644 index 83f830acbb5f..000000000000 --- a/kernel/futex_compat.c +++ /dev/null @@ -1,202 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * linux/kernel/futex_compat.c - * - * Futex compatibililty routines. - * - * Copyright 2006, Red Hat, Inc., Ingo Molnar - */ - -#include -#include -#include -#include -#include -#include - -#include - - -/* - * Fetch a robust-list pointer. Bit 0 signals PI futexes: - */ -static inline int -fetch_robust_entry(compat_uptr_t *uentry, struct robust_list __user **entry, - compat_uptr_t __user *head, unsigned int *pi) -{ - if (get_user(*uentry, head)) - return -EFAULT; - - *entry = compat_ptr((*uentry) & ~1); - *pi = (unsigned int)(*uentry) & 1; - - return 0; -} - -static void __user *futex_uaddr(struct robust_list __user *entry, - compat_long_t futex_offset) -{ - compat_uptr_t base = ptr_to_compat(entry); - void __user *uaddr = compat_ptr(base + futex_offset); - - return uaddr; -} - -/* - * Walk curr->robust_list (very carefully, it's a userspace list!) - * and mark any locks found there dead, and notify any waiters. - * - * We silently return on any sign of list-walking problem. - */ -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; - unsigned int limit = ROBUST_LIST_LIMIT, pi, pip; - unsigned int uninitialized_var(next_pi); - compat_uptr_t uentry, next_uentry, upending; - compat_long_t futex_offset; - int rc; - - if (!futex_cmpxchg_enabled) - return; - - /* - * Fetch the list head (which was registered earlier, via - * sys_set_robust_list()): - */ - if (fetch_robust_entry(&uentry, &entry, &head->list.next, &pi)) - return; - /* - * Fetch the relative futex offset: - */ - if (get_user(futex_offset, &head->futex_offset)) - return; - /* - * Fetch any possibly pending lock-add first, and handle it - * if it exists: - */ - if (fetch_robust_entry(&upending, &pending, - &head->list_op_pending, &pip)) - return; - - next_entry = NULL; /* avoid warning with gcc */ - while (entry != (struct robust_list __user *) &head->list) { - /* - * Fetch the next entry in the list before calling - * handle_futex_death: - */ - rc = fetch_robust_entry(&next_uentry, &next_entry, - (compat_uptr_t __user *)&entry->next, &next_pi); - /* - * A pending lock might already be on the list, so - * dont process it twice: - */ - if (entry != pending) { - void __user *uaddr = futex_uaddr(entry, futex_offset); - - if (handle_futex_death(uaddr, curr, pi)) - return; - } - if (rc) - return; - uentry = next_uentry; - entry = next_entry; - pi = next_pi; - /* - * Avoid excessively long or circular lists: - */ - if (!--limit) - break; - - cond_resched(); - } - if (pending) { - void __user *uaddr = futex_uaddr(pending, futex_offset); - - handle_futex_death(uaddr, curr, pip); - } -} - -COMPAT_SYSCALL_DEFINE2(set_robust_list, - struct compat_robust_list_head __user *, head, - compat_size_t, len) -{ - if (!futex_cmpxchg_enabled) - return -ENOSYS; - - if (unlikely(len != sizeof(*head))) - return -EINVAL; - - current->compat_robust_list = head; - - return 0; -} - -COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid, - compat_uptr_t __user *, head_ptr, - compat_size_t __user *, len_ptr) -{ - struct compat_robust_list_head __user *head; - unsigned long ret; - struct task_struct *p; - - if (!futex_cmpxchg_enabled) - return -ENOSYS; - - rcu_read_lock(); - - ret = -ESRCH; - if (!pid) - p = current; - else { - p = find_task_by_vpid(pid); - if (!p) - goto err_unlock; - } - - ret = -EPERM; - if (!ptrace_may_access(p, PTRACE_MODE_READ_REALCREDS)) - goto err_unlock; - - head = p->compat_robust_list; - rcu_read_unlock(); - - if (put_user(sizeof(*head), len_ptr)) - return -EFAULT; - return put_user(ptr_to_compat(head), head_ptr); - -err_unlock: - rcu_read_unlock(); - - return ret; -} - -COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val, - struct compat_timespec __user *, utime, u32 __user *, uaddr2, - u32, val3) -{ - struct timespec ts; - ktime_t t, *tp = NULL; - int val2 = 0; - int cmd = op & FUTEX_CMD_MASK; - - if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI || - cmd == FUTEX_WAIT_BITSET || - cmd == FUTEX_WAIT_REQUEUE_PI)) { - if (compat_get_timespec(&ts, utime)) - return -EFAULT; - if (!timespec_valid(&ts)) - return -EINVAL; - - t = timespec_to_ktime(ts); - if (cmd == FUTEX_WAIT) - t = ktime_add_safe(ktime_get(), t); - tp = &t; - } - if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE || - cmd == FUTEX_CMP_REQUEUE_PI || cmd == FUTEX_WAKE_OP) - val2 = (int) (unsigned long) utime; - - return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); -}