From patchwork Tue Mar 16 17:30:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 42614 X-Patchwork-Delegate: azanella@linux.vnet.ibm.com 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 4A6AD385480F; Tue, 16 Mar 2021 17:30:32 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4A6AD385480F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1615915832; bh=PRAF8oTTjzSzmMH2J7ivPXnbcgljMopP3ho+NvfFCqE=; h=To:Subject:In-Reply-To:References:Date:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=EHXRSb8RA/JfhM0mNHWOKl2306an4HnC2L9vTPshCb9//MSTRr5KJbu3bKNr+BHMd ZsXD+o5KwCj7NzI0yQxNfvyx/fwRKApIusemRY6omvDzgwQREAIfRAgzr8+S5wuXKr OAStW3h1UhnX6JSLgQuihXlxioYKxA/1g+Rbh3MQ= 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 [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id 631D6385480F for ; Tue, 16 Mar 2021 17:30:29 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 631D6385480F Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-519-9_AyKv4fPsukvRlg5hklJA-1; Tue, 16 Mar 2021 13:30:27 -0400 X-MC-Unique: 9_AyKv4fPsukvRlg5hklJA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 52F6E1934102 for ; Tue, 16 Mar 2021 17:30:26 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-112-254.ams2.redhat.com [10.36.112.254]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3F83E5D9C0 for ; Tue, 16 Mar 2021 17:30:24 +0000 (UTC) To: libc-alpha@sourceware.org Subject: [PATCH v3 23/37] nptl: Move part of TCB initialization from libpthread to __tls_init_tp In-Reply-To: References: Message-Id: <1d0192110720b4515f29fc46254ae92e6fe744e7.1615914632.git.fweimer@redhat.com> Date: Tue, 16 Mar 2021 18:30:33 +0100 User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.5 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_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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 Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" This initalization should only happen once for the main thread's TCB. At present, auditors can achieve this by not linking against libpthread. If libpthread becomes part of libc, doing this initialization in libc would happen for every audit namespace, or too late (if it happens from the main libc only). That's why moving this code into ld.so seems the right thing to do, right after the TCB initialization. For !__ASSUME_SET_ROBUST_LIST ports, this also moves the symbol __set_robust_list_avail into ld.so, as __nptl_set_robust_list_avail. It also turned into a proper boolean flag. Inline the __pthread_initialize_pids function because it seems no longer useful as a separate function. Reviewed-by: Adhemerval Zanella --- nptl/Versions | 6 +++++ nptl/nptl-init.c | 36 ++----------------------- nptl/pthread-pids.h | 29 -------------------- nptl/pthreadP.h | 6 +++-- nptl/pthread_create.c | 4 +-- nptl/pthread_mutex_init.c | 2 +- sysdeps/nptl/dl-tls_init_tp.c | 37 ++++++++++++++++++++++++++ sysdeps/unix/sysv/linux/pthread-pids.h | 29 -------------------- 8 files changed, 52 insertions(+), 97 deletions(-) delete mode 100644 nptl/pthread-pids.h delete mode 100644 sysdeps/unix/sysv/linux/pthread-pids.h diff --git a/nptl/Versions b/nptl/Versions index b619df41fb..c50a5442af 100644 --- a/nptl/Versions +++ b/nptl/Versions @@ -417,3 +417,9 @@ libpthread { __pthread_initialize_minimal; } } + +ld { + GLIBC_PRIVATE { + __nptl_set_robust_list_avail; + } +} \ No newline at end of file diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c index de64e34783..5913bf7272 100644 --- a/nptl/nptl-init.c +++ b/nptl/nptl-init.c @@ -36,7 +36,6 @@ #include #include #include -#include #include #ifndef TLS_MULTIPLE_THREADS_IN_TCB @@ -48,15 +47,6 @@ int *__libc_multiple_threads_ptr attribute_hidden; size_t __static_tls_size; size_t __static_tls_align_m1; -#ifndef __ASSUME_SET_ROBUST_LIST -/* Negative if we do not have the system call and we can use it. */ -int __set_robust_list_avail; -# define set_robust_list_not_avail() \ - __set_robust_list_avail = -1 -#else -# define set_robust_list_not_avail() do { } while (0) -#endif - /* Version of the library, used in libthread_db to detect mismatches. */ static const char nptl_version[] __attribute_used__ = VERSION; @@ -194,31 +184,9 @@ static bool __nptl_initial_report_events __attribute_used__; void __pthread_initialize_minimal_internal (void) { - /* Minimal initialization of the thread descriptor. */ + /* Partial initialization of the TCB already happened in TLS_INIT_TP + and __tls_init_tp. */ struct pthread *pd = THREAD_SELF; - __pthread_initialize_pids (pd); - THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]); - THREAD_SETMEM (pd, user_stack, true); - - /* Initialize the robust mutex data. */ - { -#if __PTHREAD_MUTEX_HAVE_PREV - pd->robust_prev = &pd->robust_head; -#endif - pd->robust_head.list = &pd->robust_head; - pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock) - - offsetof (pthread_mutex_t, - __data.__list.__next)); - int res = INTERNAL_SYSCALL_CALL (set_robust_list, &pd->robust_head, - sizeof (struct robust_list_head)); - if (INTERNAL_SYSCALL_ERROR_P (res)) - set_robust_list_not_avail (); - } - - /* Set initial thread's stack block from 0 up to __libc_stack_end. - It will be bigger than it actually is, but for unwind.c/pt-longjmp.c - purposes this is good enough. */ - THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end); /* Before initializing GL (dl_stack_user), the debugger could not find us and had to set __nptl_initial_report_events. Propagate diff --git a/nptl/pthread-pids.h b/nptl/pthread-pids.h deleted file mode 100644 index 1a0e9ade41..0000000000 --- a/nptl/pthread-pids.h +++ /dev/null @@ -1,29 +0,0 @@ -/* Initialize pid and tid fields of struct pthread. Stub version. - Copyright (C) 2015-2021 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 - . */ - -#include - -/* Initialize PD->pid and PD->tid for the initial thread. If there is - setup required to arrange that __exit_thread causes PD->tid to be - cleared and futex-woken, then this function should do that as well. */ -static inline void -__pthread_initialize_pids (struct pthread *pd) -{ -#error "sysdeps pthread-pids.h file required" - pd->pid = pd->tid = -1; -} diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h index 4b486b3577..68f8ef5aa1 100644 --- a/nptl/pthreadP.h +++ b/nptl/pthreadP.h @@ -224,8 +224,10 @@ extern unsigned int __nptl_nthreads; libc_hidden_proto (__nptl_nthreads) #ifndef __ASSUME_SET_ROBUST_LIST -/* Negative if we do not have the system call and we can use it. */ -extern int __set_robust_list_avail attribute_hidden; +/* True if the set_robust_list system call works. Initialized in + __tls_init_tp. */ +extern bool __nptl_set_robust_list_avail; +rtld_hidden_proto (__nptl_set_robust_list_avail) #endif /* Thread Priority Protection. */ diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c index 58e10e7741..51340acc4d 100644 --- a/nptl/pthread_create.c +++ b/nptl/pthread_create.c @@ -289,7 +289,7 @@ START_THREAD_DEFN __ctype_init (); #ifndef __ASSUME_SET_ROBUST_LIST - if (__set_robust_list_avail >= 0) + if (__nptl_set_robust_list_avail) #endif { /* This call should never fail because the initial call in init.c @@ -439,7 +439,7 @@ START_THREAD_DEFN /* We let the kernel do the notification if it is able to do so. If we have to do it here there for sure are no PI mutexes involved since the kernel support for them is even more recent. */ - if (__set_robust_list_avail < 0 + if (!__nptl_set_robust_list_avail && __builtin_expect (robust != (void *) &pd->robust_head, 0)) { do diff --git a/nptl/pthread_mutex_init.c b/nptl/pthread_mutex_init.c index 233cebc504..f5c3a4b464 100644 --- a/nptl/pthread_mutex_init.c +++ b/nptl/pthread_mutex_init.c @@ -95,7 +95,7 @@ __pthread_mutex_init (pthread_mutex_t *mutex, { #ifndef __ASSUME_SET_ROBUST_LIST if ((imutexattr->mutexkind & PTHREAD_MUTEXATTR_FLAG_PSHARED) != 0 - && __set_robust_list_avail < 0) + && !__nptl_set_robust_list_avail) return ENOTSUP; #endif diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c index 8983808233..c5172b7613 100644 --- a/sysdeps/nptl/dl-tls_init_tp.c +++ b/sysdeps/nptl/dl-tls_init_tp.c @@ -16,10 +16,17 @@ License along with the GNU C Library; if not, see . */ +#include #include #include +#include #include +#ifndef __ASSUME_SET_ROBUST_LIST +bool __nptl_set_robust_list_avail; +rtld_hidden_data_def (__nptl_set_robust_list_avail) +#endif + void __tls_init_tp (void) { @@ -27,4 +34,34 @@ __tls_init_tp (void) INIT_LIST_HEAD (&GL (dl_stack_used)); INIT_LIST_HEAD (&GL (dl_stack_user)); list_add (&THREAD_SELF->list, &GL (dl_stack_user)); + + /* Early initialization of the TCB. */ + struct pthread *pd = THREAD_SELF; + pd->tid = INTERNAL_SYSCALL_CALL (set_tid_address, &pd->tid); + THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]); + THREAD_SETMEM (pd, user_stack, true); + + /* Initialize the robust mutex data. */ + { +#if __PTHREAD_MUTEX_HAVE_PREV + pd->robust_prev = &pd->robust_head; +#endif + pd->robust_head.list = &pd->robust_head; + pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock) + - offsetof (pthread_mutex_t, + __data.__list.__next)); + int res = INTERNAL_SYSCALL_CALL (set_robust_list, &pd->robust_head, + sizeof (struct robust_list_head)); + if (!INTERNAL_SYSCALL_ERROR_P (res)) + { +#ifndef __ASSUME_SET_ROBUST_LIST + __nptl_set_robust_list_avail = true; +#endif + } + } + + /* Set initial thread's stack block from 0 up to __libc_stack_end. + It will be bigger than it actually is, but for unwind.c/pt-longjmp.c + purposes this is good enough. */ + THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end); } diff --git a/sysdeps/unix/sysv/linux/pthread-pids.h b/sysdeps/unix/sysv/linux/pthread-pids.h deleted file mode 100644 index 10b58899f5..0000000000 --- a/sysdeps/unix/sysv/linux/pthread-pids.h +++ /dev/null @@ -1,29 +0,0 @@ -/* Initialize pid and tid fields of struct pthread. Linux version. - Copyright (C) 2015-2021 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 - . */ - -#include -#include - -/* Initialize PD->pid and PD->tid for the initial thread. If there is - setup required to arrange that __exit_thread causes PD->tid to be - cleared and futex-woken, then this function should do that as well. */ -static inline void -__pthread_initialize_pids (struct pthread *pd) -{ - pd->tid = INTERNAL_SYSCALL_CALL (set_tid_address, &pd->tid); -}