From patchwork Thu Jun 6 14:08:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleg Nesterov X-Patchwork-Id: 10979609 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 193106C5 for ; Thu, 6 Jun 2019 14:09:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0903D289D4 for ; Thu, 6 Jun 2019 14:09:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F0DD3289D5; Thu, 6 Jun 2019 14:09:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8EA8B289A1 for ; Thu, 6 Jun 2019 14:09:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728236AbfFFOJM (ORCPT ); Thu, 6 Jun 2019 10:09:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50444 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727603AbfFFOJM (ORCPT ); Thu, 6 Jun 2019 10:09:12 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 14D6E30C34C4; Thu, 6 Jun 2019 14:08:57 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.159]) by smtp.corp.redhat.com (Postfix) with SMTP id D22F01084285; Thu, 6 Jun 2019 14:08:52 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 6 Jun 2019 16:08:56 +0200 (CEST) Date: Thu, 6 Jun 2019 16:08:52 +0200 From: Oleg Nesterov To: Andrew Morton , Deepa Dinamani Cc: linux-kernel@vger.kernel.org, arnd@arndb.de, dbueso@suse.de, axboe@kernel.dk, dave@stgolabs.net, e@80x24.org, jbaron@akamai.com, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, omar.kilani@gmail.com, tglx@linutronix.de, stable@vger.kernel.org, Al Viro , "Eric W. Biederman" , Linus Torvalds , David Laight Subject: [PATCH 1/2] select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR Message-ID: <20190606140852.GB13440@redhat.com> References: <20190522032144.10995-1-deepa.kernel@gmail.com> <20190529161157.GA27659@redhat.com> <20190604134117.GA29963@redhat.com> <20190606140814.GA13440@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190606140814.GA13440@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Thu, 06 Jun 2019 14:09:12 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP do_poll() returns -EINTR if interrupted and after that all its callers have to translate it into -ERESTARTNOHAND. Change do_poll() to return -ERESTARTNOHAND and update (simplify) the callers. Note that this also unifies all users of restore_saved_sigmask_unless(), see the next patch. Signed-off-by: Oleg Nesterov --- fs/select.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) diff --git a/fs/select.c b/fs/select.c index 1fc1b24..57712c3 100644 --- a/fs/select.c +++ b/fs/select.c @@ -925,7 +925,7 @@ static int do_poll(struct poll_list *list, struct poll_wqueues *wait, if (!count) { count = wait->error; if (signal_pending(current)) - count = -EINTR; + count = -ERESTARTNOHAND; } if (count || timed_out) break; @@ -1040,7 +1040,7 @@ static long do_restart_poll(struct restart_block *restart_block) ret = do_sys_poll(ufds, nfds, to); - if (ret == -EINTR) { + if (ret == -ERESTARTNOHAND) { restart_block->fn = do_restart_poll; ret = -ERESTART_RESTARTBLOCK; } @@ -1061,7 +1061,7 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, ret = do_sys_poll(ufds, nfds, to); - if (ret == -EINTR) { + if (ret == -ERESTARTNOHAND) { struct restart_block *restart_block; restart_block = ¤t->restart_block; @@ -1102,11 +1102,7 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, return ret; ret = do_sys_poll(ufds, nfds, to); - - restore_saved_sigmask_unless(ret == -EINTR); - /* We can restart this syscall, usually */ - if (ret == -EINTR) - ret = -ERESTARTNOHAND; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret); return ret; @@ -1135,11 +1131,7 @@ SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, return ret; ret = do_sys_poll(ufds, nfds, to); - - restore_saved_sigmask_unless(ret == -EINTR); - /* We can restart this syscall, usually */ - if (ret == -EINTR) - ret = -ERESTARTNOHAND; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret); return ret; @@ -1413,11 +1405,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, return ret; ret = do_sys_poll(ufds, nfds, to); - - restore_saved_sigmask_unless(ret == -EINTR); - /* We can restart this syscall, usually */ - if (ret == -EINTR) - ret = -ERESTARTNOHAND; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret); return ret; @@ -1446,11 +1434,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds, return ret; ret = do_sys_poll(ufds, nfds, to); - - restore_saved_sigmask_unless(ret == -EINTR); - /* We can restart this syscall, usually */ - if (ret == -EINTR) - ret = -ERESTARTNOHAND; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret); return ret; From patchwork Thu Jun 6 14:09:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleg Nesterov X-Patchwork-Id: 10979611 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0387E6C5 for ; Thu, 6 Jun 2019 14:09:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E45242838F for ; 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Thu, 6 Jun 2019 14:09:22 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.159]) by smtp.corp.redhat.com (Postfix) with SMTP id 37DB68185; Thu, 6 Jun 2019 14:09:16 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Thu, 6 Jun 2019 16:09:22 +0200 (CEST) Date: Thu, 6 Jun 2019 16:09:15 +0200 From: Oleg Nesterov To: Andrew Morton , Deepa Dinamani Cc: linux-kernel@vger.kernel.org, arnd@arndb.de, dbueso@suse.de, axboe@kernel.dk, dave@stgolabs.net, e@80x24.org, jbaron@akamai.com, linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, omar.kilani@gmail.com, tglx@linutronix.de, stable@vger.kernel.org, Al Viro , "Eric W. Biederman" , Linus Torvalds , David Laight Subject: [PATCH 2/2] select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining() Message-ID: <20190606140915.GC13440@redhat.com> References: <20190522032144.10995-1-deepa.kernel@gmail.com> <20190529161157.GA27659@redhat.com> <20190604134117.GA29963@redhat.com> <20190606140814.GA13440@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190606140814.GA13440@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Thu, 06 Jun 2019 14:09:38 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Now that restore_saved_sigmask_unless() is always called with the same argument right before poll_select_copy_remaining() we can move it into poll_select_copy_remaining() and make it the only caller of restore() in fs/select.c. The patch also renames poll_select_copy_remaining(), poll_select_finish() looks better after this change. kern_select() doesn't use set_user_sigmask(), so in this case poll_select_finish() does restore_saved_sigmask_unless() "for no reason". But this won't hurt, and WARN_ON(!TIF_SIGPENDING) is still valid. Signed-off-by: Oleg Nesterov --- fs/select.c | 46 +++++++++++++--------------------------------- 1 file changed, 13 insertions(+), 33 deletions(-) diff --git a/fs/select.c b/fs/select.c index 57712c3..51ceec2 100644 --- a/fs/select.c +++ b/fs/select.c @@ -294,12 +294,14 @@ enum poll_time_type { PT_OLD_TIMESPEC = 3, }; -static int poll_select_copy_remaining(struct timespec64 *end_time, - void __user *p, - enum poll_time_type pt_type, int ret) +static int poll_select_finish(struct timespec64 *end_time, + void __user *p, + enum poll_time_type pt_type, int ret) { struct timespec64 rts; + restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); + if (!p) return ret; @@ -714,9 +716,7 @@ static int kern_select(int n, fd_set __user *inp, fd_set __user *outp, } ret = core_sys_select(n, inp, outp, exp, to); - ret = poll_select_copy_remaining(&end_time, tvp, PT_TIMEVAL, ret); - - return ret; + return poll_select_finish(&end_time, tvp, PT_TIMEVAL, ret); } SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp, @@ -757,10 +757,7 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, return ret; ret = core_sys_select(n, inp, outp, exp, to); - restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); - ret = poll_select_copy_remaining(&end_time, tsp, type, ret); - - return ret; + return poll_select_finish(&end_time, tsp, type, ret); } /* @@ -1102,10 +1099,7 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, return ret; ret = do_sys_poll(ufds, nfds, to); - restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); - ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret); - - return ret; + return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); } #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) @@ -1131,10 +1125,7 @@ SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, return ret; ret = do_sys_poll(ufds, nfds, to); - restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); - ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret); - - return ret; + return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); } #endif @@ -1271,9 +1262,7 @@ static int do_compat_select(int n, compat_ulong_t __user *inp, } ret = compat_core_sys_select(n, inp, outp, exp, to); - ret = poll_select_copy_remaining(&end_time, tvp, PT_OLD_TIMEVAL, ret); - - return ret; + return poll_select_finish(&end_time, tvp, PT_OLD_TIMEVAL, ret); } COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp, @@ -1333,10 +1322,7 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp, return ret; ret = compat_core_sys_select(n, inp, outp, exp, to); - restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); - ret = poll_select_copy_remaining(&end_time, tsp, type, ret); - - return ret; + return poll_select_finish(&end_time, tsp, type, ret); } COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp, @@ -1405,10 +1391,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, return ret; ret = do_sys_poll(ufds, nfds, to); - restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); - ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret); - - return ret; + return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); } #endif @@ -1434,10 +1417,7 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds, return ret; ret = do_sys_poll(ufds, nfds, to); - restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); - ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret); - - return ret; + return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); } #endif