From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 CD2113951884 for ; Sun, 9 May 2021 21:42:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org CD2113951884 Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-19-IqcUmIU5N8GrOz9GBkn08A-1; Sun, 09 May 2021 17:42:22 -0400 X-MC-Unique: IqcUmIU5N8GrOz9GBkn08A-1 Received: by mail-qv1-f69.google.com with SMTP id r11-20020a0cb28b0000b02901c87a178503so10956653qve.22 for ; Sun, 09 May 2021 14:42:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=lffvuKTYKHSB2CKWOJuqdWm9xtTBG11dvLP/aAwsXEo=; b=s7w0RoCO3I7Oo3B5+YZ/YOxnsv8R1KQ86j2nddwQgplQ6uQ2n3geTL0q2XfFLuxjRm ZGBILH0h/IEE4wB1toM31xHB8Bh5U2ngx/w3zZ6CTTiEa6ElHo75stexepcbwtgVc5Tt qElYrEcb0aKS/UXZmdlXNXclUVf0E3r6XyOG9HcGbKPQV3YsGr3qIjGB9wiIRICH47up rfjp2KyRz54L+R8b+thN6mb74RQ16pyOw1nwcKdDbfjW5BfGHpz10lGuGsCNp8+xPyDD wzVxlLEhNnC4XZ7vtS7Ka/zfl1jq3oeNizcLTibU1cvtB6rJ3X8+9TNM91tHj4LfgIcO wB+g== X-Gm-Message-State: AOAM532Nu0y4ZgY5GgYdUv2XdM6oBgVvEcoCYY/0W1AiYvrzEIKyoDcT BSIUGVrW+UmNQeB0v36lRNRCCopb0mQrcRZFcxcYJKv/93Xr6Q3UdU+YniGuVpJw9CctgwR4z6+ ykTFexbz7/Y8jdI/dIvjMmiJiOKU+EMEQ9m7k4JJg/XtODuUwWtbrRVkjUJJ57BMIsUwVZg== X-Received: by 2002:ae9:dc41:: with SMTP id q62mr19437940qkf.22.1620596542073; Sun, 09 May 2021 14:42:22 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwRCIDKV4cjHzl6vUdhK5mfKmWL4djDwcR7C1MFFibFKSmVfUcvKDv0VCvnryd75oiO5qS9sA== X-Received: by 2002:ae9:dc41:: with SMTP id q62mr19437926qkf.22.1620596541792; Sun, 09 May 2021 14:42:21 -0700 (PDT) Received: from [192.168.1.16] (198-84-214-74.cpe.teksavvy.com. [198.84.214.74]) by smtp.gmail.com with ESMTPSA id a10sm10619518qtm.16.2021.05.09.14.42.20 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 09 May 2021 14:42:21 -0700 (PDT) Subject: Re: [PATCH 03/13] nptl: Export __libc_multiple_threads from libc as an internal symbol To: Florian Weimer , libc-alpha@sourceware.org References: <01385e388d7d2659f3562229d5cd61d27683f40a.1620323953.git.fweimer@redhat.com> From: Carlos O'Donell Organization: Red Hat Message-ID: <1d8f3c3d-dd55-80c4-ad41-869c100a39d5@redhat.com> Date: Sun, 9 May 2021 17:42:20 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <01385e388d7d2659f3562229d5cd61d27683f40a.1620323953.git.fweimer@redhat.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-12.0 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, NICE_REPLY_A, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, 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-List-Received-Date: Sun, 09 May 2021 21:42:26 -0000 On 5/6/21 2:10 PM, Florian Weimer via Libc-alpha wrote: > This allows the elimination of the __libc_multiple_threads_ptr > variable in libpthread and its initialization procedure. LGTM. Tested on x86_64 and i686 without regression. Tested-by: Carlos O'Donell Reviewed-by: Carlos O'Donell > --- > nptl/Versions | 1 + > nptl/allocatestack.c | 4 ++-- > nptl/libc_multiple_threads.c | 3 ++- > nptl/libc_pthread_init.c | 11 ----------- > nptl/nptl-init.c | 10 +--------- > nptl/pthreadP.h | 6 +----- > nptl/pthread_cancel.c | 2 +- > sysdeps/unix/sysv/linux/single-thread.h | 6 +++++- > 8 files changed, 13 insertions(+), 30 deletions(-) > > diff --git a/nptl/Versions b/nptl/Versions > index f950b77969..fb15a7e8eb 100644 > --- a/nptl/Versions > +++ b/nptl/Versions > @@ -305,6 +305,7 @@ libc { > __libc_cleanup_pop_restore; > __libc_cleanup_push_defer; > __libc_dl_error_tsd; > + __libc_multiple_threads; > __libc_pthread_init; > __lll_clocklock_elision; > __lll_lock_elision; > diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c > index 8aaba088b1..059786192e 100644 > --- a/nptl/allocatestack.c > +++ b/nptl/allocatestack.c > @@ -477,7 +477,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, > /* This is at least the second thread. */ > pd->header.multiple_threads = 1; > #ifndef TLS_MULTIPLE_THREADS_IN_TCB > - __pthread_multiple_threads = *__libc_multiple_threads_ptr = 1; > + __pthread_multiple_threads = __libc_multiple_threads = 1; > #endif > > #ifdef NEED_DL_SYSINFO > @@ -598,7 +598,7 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, > /* This is at least the second thread. */ > pd->header.multiple_threads = 1; > #ifndef TLS_MULTIPLE_THREADS_IN_TCB > - __pthread_multiple_threads = *__libc_multiple_threads_ptr = 1; > + __pthread_multiple_threads = __libc_multiple_threads = 1; > #endif > > #ifdef NEED_DL_SYSINFO > diff --git a/nptl/libc_multiple_threads.c b/nptl/libc_multiple_threads.c > index 60328023cd..a0e7932c26 100644 > --- a/nptl/libc_multiple_threads.c > +++ b/nptl/libc_multiple_threads.c > @@ -23,6 +23,7 @@ > /* Variable set to a nonzero value either if more than one thread runs or ran, > or if a single-threaded process is trying to cancel itself. See > nptl/descr.h for more context on the single-threaded process case. */ > -int __libc_multiple_threads attribute_hidden; > +int __libc_multiple_threads __attribute__ ((nocommon)); > +libc_hidden_data_def (__libc_multiple_threads) > # endif > #endif > diff --git a/nptl/libc_pthread_init.c b/nptl/libc_pthread_init.c > index 397b83beb6..75f5d28ed6 100644 > --- a/nptl/libc_pthread_init.c > +++ b/nptl/libc_pthread_init.c > @@ -27,20 +27,9 @@ > #include > #include > > - > -#ifdef TLS_MULTIPLE_THREADS_IN_TCB > void > -#else > -extern int __libc_multiple_threads attribute_hidden; > - > -int * > -#endif > __libc_pthread_init (void (*reclaim) (void)) > { > /* Called by a child after fork. */ > __register_atfork (NULL, NULL, reclaim, NULL); > - > -#ifndef TLS_MULTIPLE_THREADS_IN_TCB > - return &__libc_multiple_threads; > -#endif > } > diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c > index 2724770533..2fb1117f3e 100644 > --- a/nptl/nptl-init.c > +++ b/nptl/nptl-init.c > @@ -37,11 +37,6 @@ > #include > #include > > -#ifndef TLS_MULTIPLE_THREADS_IN_TCB > -/* Pointer to the corresponding variable in libc. */ > -int *__libc_multiple_threads_ptr attribute_hidden; > -#endif > - > /* Size and alignment of static TLS block. */ > size_t __static_tls_size; > size_t __static_tls_align_m1; > @@ -183,10 +178,7 @@ __pthread_initialize_minimal_internal (void) > #endif > > /* Register the fork generation counter with the libc. */ > -#ifndef TLS_MULTIPLE_THREADS_IN_TCB > - __libc_multiple_threads_ptr = > -#endif > - __libc_pthread_init (__reclaim_stacks); > + __libc_pthread_init (__reclaim_stacks); > } > strong_alias (__pthread_initialize_minimal_internal, > __pthread_initialize_minimal) > diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h > index 6b52ca158e..dd6d6c6342 100644 > --- a/nptl/pthreadP.h > +++ b/nptl/pthreadP.h > @@ -368,17 +368,13 @@ extern unsigned long int __fork_generation attribute_hidden; > extern unsigned long int *__fork_generation_pointer attribute_hidden; > > /* Register the generation counter in the libpthread with the libc. */ > -#ifdef TLS_MULTIPLE_THREADS_IN_TCB > extern void __libc_pthread_init (void (*reclaim) (void)); > -#else > -extern int *__libc_pthread_init (void (*reclaim) (void)); > > +#ifndef TLS_MULTIPLE_THREADS_IN_TCB > /* Variable set to a nonzero value either if more than one thread runs or ran, > or if a single-threaded process is trying to cancel itself. See > nptl/descr.h for more context on the single-threaded process case. */ > extern int __pthread_multiple_threads attribute_hidden; > -/* Pointer to the corresponding variable in libc. */ > -extern int *__libc_multiple_threads_ptr attribute_hidden; > #endif > > extern size_t __pthread_get_minstack (const pthread_attr_t *attr); > diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c > index 060484cdc8..2cab8f0a34 100644 > --- a/nptl/pthread_cancel.c > +++ b/nptl/pthread_cancel.c > @@ -90,7 +90,7 @@ __pthread_cancel (pthread_t th) > points get executed. */ > THREAD_SETMEM (THREAD_SELF, header.multiple_threads, 1); > #ifndef TLS_MULTIPLE_THREADS_IN_TCB > - __pthread_multiple_threads = *__libc_multiple_threads_ptr = 1; > + __pthread_multiple_threads = __libc_multiple_threads = 1; > #endif > } > /* Mark the thread as canceled. This has to be done > diff --git a/sysdeps/unix/sysv/linux/single-thread.h b/sysdeps/unix/sysv/linux/single-thread.h > index a28aaed04d..841f8c69d5 100644 > --- a/sysdeps/unix/sysv/linux/single-thread.h > +++ b/sysdeps/unix/sysv/linux/single-thread.h > @@ -27,9 +27,13 @@ > The ABI might define SINGLE_THREAD_BY_GLOBAL to enable the single thread > check to use global variables instead of the pthread_t field. */ > > +#ifndef __ASSEMBLER__ > +extern int __libc_multiple_threads; > +libc_hidden_proto (__libc_multiple_threads) > +#endif > + > #ifdef SINGLE_THREAD_BY_GLOBAL > # if IS_IN (libc) > -extern int __libc_multiple_threads; > # define SINGLE_THREAD_P \ > __glibc_likely (__libc_multiple_threads == 0) > # elif IS_IN (libpthread) > -- Cheers, Carlos.