From nobody Thu Nov 14 01:34:26 2024 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4XpjPH3Zm4z5cskP; Thu, 14 Nov 2024 01:34:27 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R10" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4XpjPH1cVcz42Sy; Thu, 14 Nov 2024 01:34:27 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1731548067; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ooJ9eFjnV+1AY8URObRU2Iyt/xEU3d211+wQ23itRx4=; b=K1UUcYZAqBNIySbtGvfCQCS4cdvrAeuMNYVkXa2mg5Vk97Cs6lpdwau86fbu86b/IVer9o fYBvBJT7P4ZIvCVLsUHhlYYdGDJxXBWCtaePb9C83KYSED2Y4XdJmvw12wqbkjYSNrNqh4 IJIfyYPKoLU+HIj+CtkX5PZSpdZd/POjCuPuHCzyRSEq0Cv21vEmJPstSTYQNe93HGCxCT UqFVpbU8Cn1WZ1rEwb195UIkILPNJvqaG/ejQcnO0MUgz2iKlSzEMqwB7ImzQJm+NHxSzM xA5KB+d/p15LjVxsa019wSLn73Sil2iX+fmyqT2FnvlCTaQ+t35HQRbWgdc7rQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1731548067; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ooJ9eFjnV+1AY8URObRU2Iyt/xEU3d211+wQ23itRx4=; b=flkM8YnD23tU9qYQSH72AcFEJhpJCRH6x+4ODHuZMeft9r2/K1MLDiTxESd0W9PaDvyyoF EGBIKt0h0XbO6akoBVUM8W5khl2qgKDQDH7tjCE0TIdRkKXfhckqxqS2D1AGi5eRKL3OK8 EM/nR4UqF/JM5DZBw89qKLDDz5lQutyhzZRXXPICIGO7HFOZ2NK4UFXLnp7iTRDesv6IG7 gou6zc9p4IMeGa0jMejArhWzHXUg7GnWtPItCnnr/pApXW6ZKP3qpH/4+vDPudgdxCqEkT trQjkDHFTLWSOP5nCfO0M1U/Iiu/HWE8up9jrHkLF/EsYEIq5Gyzk9ttR8bltA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1731548067; a=rsa-sha256; cv=none; b=QrDQIkvZ73efNr5lk4cBgfoY7XKMwIaJWALEvmlOpx96nwiOhPBPN14xxFysMOC0Qm2iRZ 7iOsMlpjyvuMPVmkYIY46YiFbje8w4sVIa8QZMJ7H8gETU3hhwrgquIC/4JRYbZ4Q+UGhK lEXGtB0EjR7QjefS8AtKXPDdmgUicsufHizlbBgDeU2QyyY2ac4sdX1fHWsphPZHDak6mc n9GP4GDH/F0iVmPQnky7L74e0c+G/qqPiLJslPK5jue8tdI3IUunkmSoZwD7DZRGrGSvsI +BRLEd2vaLFVXLyc1WLR+6Pq9OgX+0h8a0UVQYqPnkfwyb8SWxHxMsGLylg4kg== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4XpjPH0MsyzJZZ; Thu, 14 Nov 2024 01:34:27 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 4AE1YQB6018030; Thu, 14 Nov 2024 01:34:26 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 4AE1YQmG018027; Thu, 14 Nov 2024 01:34:26 GMT (envelope-from git) Date: Thu, 14 Nov 2024 01:34:26 GMT Message-Id: <202411140134.4AE1YQmG018027@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Kyle Evans Subject: git: 4b202f4faf40 - main - libthr: allow very early atfork registration List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kevans X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 4b202f4faf40fd7af8b84491360186aed8ce5733 Auto-Submitted: auto-generated The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=4b202f4faf40fd7af8b84491360186aed8ce5733 commit 4b202f4faf40fd7af8b84491360186aed8ce5733 Author: Kyle Evans AuthorDate: 2024-11-14 01:33:44 +0000 Commit: Kyle Evans CommitDate: 2024-11-14 01:33:44 +0000 libthr: allow very early atfork registration LSan wants to be able to register atfork handlers at __lsan_init time, which can happen either at the first intercepted function call or in a .preinit_array function. Both of these end up being very early in rtld and executed with the bind lock held, which ends up causing problems when we go to _libpthread_init(). Instead of requiring libpthread to be initialized, just insert the new atfork handler straight into the list if it's not ready yet. The critical section and locking should not be necessary if we're really executing this early, as there won't be any threads to contend with. Reviewed by: kib (earlier version), markj Differential Revision: https://reviews.freebsd.org/D47349 --- lib/libthr/tests/atfork_test.c | 53 ++++++++++++++++++++++++++++++++++++++++++ lib/libthr/thread/thr_fork.c | 20 +++++++++------- lib/libthr/thread/thr_init.c | 1 - 3 files changed, 65 insertions(+), 9 deletions(-) diff --git a/lib/libthr/tests/atfork_test.c b/lib/libthr/tests/atfork_test.c index 5133330b1247..cb0fcb7e62db 100644 --- a/lib/libthr/tests/atfork_test.c +++ b/lib/libthr/tests/atfork_test.c @@ -25,6 +25,58 @@ static int child; static int forked; static int parent; +/* + * We'll disable prefork unless we're specifically running the preinit test to + * be sure that we don't mess up any other tests' results. + */ +static bool prefork_enabled; + +static void +prefork(void) +{ + if (prefork_enabled) + forked++; +} + +static void +registrar(void) +{ + pthread_atfork(prefork, NULL, NULL); +} + +static __attribute__((section(".preinit_array"), used)) +void (*preinitfn)(void) = ®istrar; + +/* + * preinit_atfork() just enables the prepare handler that we registered in a + * .preinit_array entry and checks that forking actually invoked that callback. + * We don't bother testing all three callbacks here because the implementation + * doesn't really lend itself to the kind of error where we only have a partial + * set of callbacks registered. + */ +ATF_TC(preinit_atfork); +ATF_TC_HEAD(preinit_atfork, tc) +{ + atf_tc_set_md_var(tc, "descr", + "Checks that atfork callbacks may be registered in .preinit_array functions"); +} +ATF_TC_BODY(preinit_atfork, tc) +{ + pid_t p; + + (void)signal(SIGCHLD, SIG_IGN); + prefork_enabled = true; + p = fork(); + + ATF_REQUIRE(p >= 0); + if (p == 0) + _exit(0); + + prefork_enabled = false; + + ATF_REQUIRE(forked != 0); +} + static void basic_prepare(void) { @@ -221,6 +273,7 @@ ATF_TC_BODY(multi_atfork, tc) ATF_TP_ADD_TCS(tp) { + ATF_TP_ADD_TC(tp, preinit_atfork); ATF_TP_ADD_TC(tp, basic_atfork); ATF_TP_ADD_TC(tp, multi_atfork); return (atf_no_error()); diff --git a/lib/libthr/thread/thr_fork.c b/lib/libthr/thread/thr_fork.c index 614841cc314f..aa54b0444cf4 100644 --- a/lib/libthr/thread/thr_fork.c +++ b/lib/libthr/thread/thr_fork.c @@ -84,20 +84,24 @@ _thr_atfork(void (*prepare)(void), void (*parent)(void), struct pthread *curthread; struct pthread_atfork *af; - _thr_check_init(); - if ((af = malloc(sizeof(struct pthread_atfork))) == NULL) return (ENOMEM); - curthread = _get_curthread(); af->prepare = prepare; af->parent = parent; af->child = child; - THR_CRITICAL_ENTER(curthread); - _thr_rwl_wrlock(&_thr_atfork_lock); - TAILQ_INSERT_TAIL(&_thr_atfork_list, af, qe); - _thr_rwl_unlock(&_thr_atfork_lock); - THR_CRITICAL_LEAVE(curthread); + + if (_thr_initial != NULL) { + curthread = _get_curthread(); + THR_CRITICAL_ENTER(curthread); + _thr_rwl_wrlock(&_thr_atfork_lock); + TAILQ_INSERT_TAIL(&_thr_atfork_list, af, qe); + _thr_rwl_unlock(&_thr_atfork_lock); + THR_CRITICAL_LEAVE(curthread); + } else { + TAILQ_INSERT_TAIL(&_thr_atfork_list, af, qe); + } + return (0); } diff --git a/lib/libthr/thread/thr_init.c b/lib/libthr/thread/thr_init.c index 007cf5be81c9..ff59288d919e 100644 --- a/lib/libthr/thread/thr_init.c +++ b/lib/libthr/thread/thr_init.c @@ -519,7 +519,6 @@ init_private(void) env = getenv("LIBPTHREAD_QUEUE_FIFO"); if (env) _thr_queuefifo = atoi(env); - TAILQ_INIT(&_thr_atfork_list); env = getenv("LIBPTHREAD_UMTX_MIN_TIMEOUT"); if (env) { char *endptr;