From patchwork Fri Dec 7 21:18:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 153215 Delivered-To: patch@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp982080ljp; Fri, 7 Dec 2018 13:18:41 -0800 (PST) X-Google-Smtp-Source: AFSGD/VWLEp4pVTP/wKwMOHkH74E/jWQfWfUv6x0ILJPhBpQgV8RnvRn6uQ9Ua6mjjJ64TZbEY+l X-Received: by 2002:a17:902:2862:: with SMTP id e89mr3697518plb.158.1544217520982; Fri, 07 Dec 2018 13:18:40 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1544217520; cv=none; d=google.com; s=arc-20160816; b=JTo2o55ItgSwhhfzf79N7gXPSd/9kDi98dyT2m0XoUEGV6bQ7zrcgZnWo6wvsdrvmk Ir29veZ9Gqqu6x4KuJAmSNHWREP6MQAtSQuQrAAcLUTNEGJ/DQqhu0P4uA1k7Sna3YRT r8VJapb3orAF9WSauBR3dz48s5ZxcawN9eGCbcObHvM9TKhdA5/heAZdjo1W8j1HJXH1 2DIhXyuDGX7/a7QTXLgAvAtE3CEgU3M0uKoSjxIBsWcUSIiYDdgUBwqY27TDXD13abwW kvU2iHORPCi2YRCbmgBlCe6ddtKkMLjJT2FpYpNzff9g32mOslGuNGNZzJVZ1uiwpu6T TP+Q== 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; bh=Yskc8CimzkLWSHK0I2AvTq9v4OpR7z7/pvc2TCvWL88=; b=m/Ww4S1hbxt04CZ11og+lipSMlMZ0sk0JZEtr2x3ZNA5AKoz21UKJpp4d7Qj/PdIs7 3GRn09qzyY7gEyG3TwJlpLugW0oODWPJb1wTny6k3giB7KgPYzVk+oSH4Sos/Lu73LbS GabZeH4NDRsfyqfC5T11JehoD9t8y/ZD07m/U0YUY3+rPRcZ4DUz6omSfFm4gk5YEAWt +I1S/+oY9YM0mtf1wS9O5ckpT51xfXyTfpCPZ4JNTF+QzgQI2dSYumGkDnwHVDXjVKi9 0IPC7oUVjcVV6XZdlOBEQ6KAe1AshDU0iSllqdOg6/nPw0vWLoLyhG9xJOyuCZYyTVgE iTQw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-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 n18si4080282pfj.30.2018.12.07.13.18.40; Fri, 07 Dec 2018 13:18:40 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-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 linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726270AbeLGVSh (ORCPT + 31 others); Fri, 7 Dec 2018 16:18:37 -0500 Received: from mout.kundenserver.de ([212.227.126.130]:39695 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726041AbeLGVSV (ORCPT ); Fri, 7 Dec 2018 16:18:21 -0500 Received: from wuerfel.lan ([109.192.41.194]) by mrelayeu.kundenserver.de (mreue009 [212.227.15.129]) with ESMTPA (Nemesis) id 1MsYzD-1hJUzZ40SZ-00tzHj; Fri, 07 Dec 2018 22:18:11 +0100 From: Arnd Bergmann To: y2038@lists.linaro.org Cc: linux-kernel@vger.kernel.org, Deepa Dinamani , John Stultz , Thomas Gleixner , linux-api@vger.kernel.org, Arnd Bergmann Subject: [PATCH 1/5] y2038: futex: Move compat implementation into futex.c Date: Fri, 7 Dec 2018 22:18:04 +0100 Message-Id: <20181207211808.328719-2-arnd@arndb.de> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20181207211808.328719-1-arnd@arndb.de> References: <20181207211808.328719-1-arnd@arndb.de> X-Provags-ID: V03:K1:l9X29fKB2TzHub3lxGs6a6uk9ozAb5My4ZxqYnF1Wc8SxZnpKWj qCPttoMkrI6PYxQfivJGEtlD5PATMocHuLGe21OI/FhI2DzJN06RHUDwGHjMTKwDbmnFHH4 kZtm2gtAePbb8r9LiVJP1jsTKbPYx2gd/xi4Ha1aysADyhG4Vjm4i6LVY00RVXIuW1PfLTR QAA8/4BLl0yXo0PqQnPJw== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1; V03:K0:3bcp9Hjq7kQ=:LwnBFx33KMah5m0wj132EU LbTczo+4JDDIXgP5QKfkub8MqUfrSBZ7WrKIq6R+8GnViOYF4Y43VhgvwyM6ue1t+zqnV4mWd 17EHqi2MeahPMY5hTFP3z0TGWKdKnQy+IBAvvSzhb2WGeU+jZxB4SbuF/qwUWBITiuYEIANq4 n4Tp+3LHt8cCgA1/0JEm/2eTQG1tu+tYqXhWki8j8G1ApYnyH+C9tyEZq3slgHfTQqEW5G3Nq 5PR77czoyRaK3flEBO/01AP1q5LPMJ3f0PGwSZSQxtGPXRUQ1dZCiIQhsGYaqLS1WDC8FaAEs 2MfFS/6ERBRG9Sq1+TV9ZbnyIj771WeIXEco4bXwz1C+fNTdAq7AIw1TnN1lkGfBuWULqkVj+ VjYV8Yvn9//Gaf/LF22eHhNBL4Fp/ea9a6PGdzer6CU8XqzgWowdRl/hd/rlMp/jtYutTtNcP BDT4vEDqaDopr5feAs0l+QkS4+BHcHnaIlgAUrwovyqXQYirJlekM8CH4utq99FYxMCwNU55a 1XnyGPWiu9fv7lIB1sB0q4HghBcLBu3HIBETimjaBEjy4N+yx9WnUTTRGtX1VFSoy/JgSZzn5 etlpBx4zg3Nnr0+IRtIKF5pZuttPmC/46xHY8XRuzqqfVGpIREDNcTDMqLB0QZMTUEAhidNr3 uJFggVb/KI7idF8QMV4qnNpO7XLQG8R1kRV4J1QudqBpdgCVTxXKVgMmCRunwxzabpSrkm6om 9X0O7um+5xZZcdbH3Ppjk8JaQoTVKEuVERwtHw== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 --- 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 -- 2.18.0 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 f423f9b6577e..5cc7c3b098e9 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; @@ -3589,6 +3592,192 @@ 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 old_timespec32 __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 410a77a8f6e2..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 old_timespec32 __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); -}