From owner-dev-commits-src-all@freebsd.org Tue Jan 12 10:46:21 2021 Return-Path: Delivered-To: dev-commits-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id A79154D227B; Tue, 12 Jan 2021 10:46:21 +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 "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4DFS192wkZz4lSS; Tue, 12 Jan 2021 10:46:21 +0000 (UTC) (envelope-from git@FreeBSD.org) 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 310912BA95; Tue, 12 Jan 2021 10:46:21 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 10CAkLxX018199; Tue, 12 Jan 2021 10:46:21 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 10CAkLxI018198; Tue, 12 Jan 2021 10:46:21 GMT (envelope-from git) Date: Tue, 12 Jan 2021 10:46:21 GMT Message-Id: <202101121046.10CAkLxI018198@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: 85d028223bc2 - main - libthr malloc: support recursion on thr_malloc_umtx. MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 85d028223bc2768651f4d44881644ceb5dc2a664 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Jan 2021 10:46:21 -0000 The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=85d028223bc2768651f4d44881644ceb5dc2a664 commit 85d028223bc2768651f4d44881644ceb5dc2a664 Author: Konstantin Belousov AuthorDate: 2021-01-12 09:02:37 +0000 Commit: Konstantin Belousov CommitDate: 2021-01-12 10:45:44 +0000 libthr malloc: support recursion on thr_malloc_umtx. One possible way the recursion can happen is during fork: suppose that fork is called from early code that did not triggered jemalloc(3) initialization yet. Then we lock thr_malloc lock, and call malloc_prefork() that might require initialization of jemalloc pthread_mutexes, calling into libthr malloc. It is safe to allow recursion for this occurence. PR: 252579 Reported by: Vasily Postnicov MFC after: 1 week Sponsored by: The FreeBSD Foundation --- lib/libthr/thread/thr_malloc.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/lib/libthr/thread/thr_malloc.c b/lib/libthr/thread/thr_malloc.c index 2f1c81142942..80a81f9c6c27 100644 --- a/lib/libthr/thread/thr_malloc.c +++ b/lib/libthr/thread/thr_malloc.c @@ -41,6 +41,7 @@ int npagesizes; size_t *pagesizes; static size_t pagesizes_d[2]; static struct umutex thr_malloc_umtx; +static u_int thr_malloc_umtx_level; void __thr_malloc_init(void) @@ -60,11 +61,16 @@ __thr_malloc_init(void) static void thr_malloc_lock(struct pthread *curthread) { + uint32_t curtid; if (curthread == NULL) return; curthread->locklevel++; - _thr_umutex_lock(&thr_malloc_umtx, TID(curthread)); + curtid = TID(curthread); + if ((uint32_t)thr_malloc_umtx.m_owner == curtid) + thr_malloc_umtx_level++; + else + _thr_umutex_lock(&thr_malloc_umtx, curtid); } static void @@ -73,7 +79,10 @@ thr_malloc_unlock(struct pthread *curthread) if (curthread == NULL) return; - _thr_umutex_unlock(&thr_malloc_umtx, TID(curthread)); + if (thr_malloc_umtx_level > 0) + thr_malloc_umtx_level--; + else + _thr_umutex_unlock(&thr_malloc_umtx, TID(curthread)); curthread->locklevel--; _thr_ast(curthread); }