From patchwork Thu Nov 18 20:03:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 47904 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 9A80F385C413 for ; Thu, 18 Nov 2021 20:04:36 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9A80F385C413 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1637265876; bh=rk8KnGcKxBlANqeQcUB6fGFNaVkc06/VqqFRvZ5jAA4=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:Cc:From; b=TBQ4ESDhC6g34DvBMBq0MM2+N9qnS4y3ePzgkiOiq70p6JezZLB1AvqfSYTr+2avf gXjmwYp+KaZdd7FEaMZ1NGCKlZlUfHg8mCss16z+/Fs4VmS4edDoDRCQlaPZ95alVA ObQ/QuK4m99EsQvcr8NMebqIHN7JWTn4m36NRxis= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id C0D5F385C413 for ; Thu, 18 Nov 2021 20:03:38 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org C0D5F385C413 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-580-1XANCbnsMNOHnHT-KbFfGQ-1; Thu, 18 Nov 2021 15:03:28 -0500 X-MC-Unique: 1XANCbnsMNOHnHT-KbFfGQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E91391019982; Thu, 18 Nov 2021 20:03:27 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.131]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1BBCE57CAD; Thu, 18 Nov 2021 20:03:26 +0000 (UTC) To: libc-alpha@sourceware.org Subject: [PATCH] nptl: Do not set signal mask on second setjmp return [BZ #28607] Date: Thu, 18 Nov 2021 21:03:25 +0100 Message-ID: <87sfvtcjua.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.6 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Florian Weimer via Libc-alpha From: Florian Weimer Reply-To: Florian Weimer Cc: Gibeom Gwon Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" __libc_signal_restore_set was in the wrong place: It also ran when setjmp returned the second time (after pthread_exit or pthread_cancel). This is observable with blocked pending signals during thread exit. Tested on i686-linux-gnu and x86_64-linux-gnu. Reviewed-by: Adhemerval Zanella --- nptl/pthread_create.c | 4 +-- sysdeps/pthread/Makefile | 1 + sysdeps/pthread/tst-pthread-exit-signal.c | 45 +++++++++++++++++++++++++++++++ 3 files changed, 48 insertions(+), 2 deletions(-) diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c index d6ea43a754..bad9eeb52f 100644 --- a/nptl/pthread_create.c +++ b/nptl/pthread_create.c @@ -406,8 +406,6 @@ start_thread (void *arg) unwind_buf.priv.data.prev = NULL; unwind_buf.priv.data.cleanup = NULL; - __libc_signal_restore_set (&pd->sigmask); - /* Allow setxid from now onwards. */ if (__glibc_unlikely (atomic_exchange_acq (&pd->setxid_futex, 0) == -2)) futex_wake (&pd->setxid_futex, 1, FUTEX_PRIVATE); @@ -417,6 +415,8 @@ start_thread (void *arg) /* Store the new cleanup handler info. */ THREAD_SETMEM (pd, cleanup_jmp_buf, &unwind_buf); + __libc_signal_restore_set (&pd->sigmask); + LIBC_PROBE (pthread_start, 3, (pthread_t) pd, pd->start_routine, pd->arg); /* Run the code the user provided. */ diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile index df8943f486..c657101696 100644 --- a/sysdeps/pthread/Makefile +++ b/sysdeps/pthread/Makefile @@ -118,6 +118,7 @@ tests += tst-cnd-basic tst-mtx-trylock tst-cnd-broadcast \ tst-unload \ tst-unwind-thread \ tst-pt-vfork1 tst-pt-vfork2 tst-vfork1x tst-vfork2x \ + tst-pthread-exit-signal \ tst-pthread-setuid-loop \ tst-pthread_cancel-exited \ tst-pthread_cancel-select-loop \ diff --git a/sysdeps/pthread/tst-pthread-exit-signal.c b/sysdeps/pthread/tst-pthread-exit-signal.c new file mode 100644 index 0000000000..b4526fe663 --- /dev/null +++ b/sysdeps/pthread/tst-pthread-exit-signal.c @@ -0,0 +1,45 @@ +/* Test that pending signals are not delivered on thread exit (bug 28607). + Copyright (C) 2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +/* Due to bug 28607, pthread_kill (or pthread_cancel) restored the + signal mask during during thread exit, triggering the delivery of a + blocked pending signal (SIGUSR1 in this test). */ + +#include +#include + +static void * +threadfunc (void *closure) +{ + sigset_t sigmask; + sigfillset (&sigmask); + xpthread_sigmask (SIG_SETMASK, &sigmask, NULL); + xpthread_kill (pthread_self (), SIGUSR1); + pthread_exit (NULL); + return NULL; +} + +static int +do_test (void) +{ + pthread_t thr = xpthread_create (NULL, threadfunc, NULL); + xpthread_join (thr); + return 0; +} + +#include