From patchwork Fri Jun 26 19:32:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Walker X-Patchwork-Id: 39806 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 74DD6388C017; Fri, 26 Jun 2020 19:32:39 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 74DD6388C017 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1593199959; bh=efBXlb0wW094ARnZ8opWq+dXytJnFABb43DVraNGef4=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:Cc:From; b=YS4+sPGvy1iMdgaYbHs4/hTrfcnh7o9T61TfDUTzSd/EWsPuykQTjNm533aFKYZHD 8Mj1VMenYV4RO1RZxHwsvcGjLsuUSbDV5aOGf3kgKKCjKyPG7bTdyPl84QKqPmXftS h5XCR44ev8NFGBHh5lZ0D0LrcsQJyUWQK9wXzqEk= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from rcdn-iport-7.cisco.com (rcdn-iport-7.cisco.com [173.37.86.78]) by sourceware.org (Postfix) with ESMTPS id C4B7F386F83E for ; Fri, 26 Jun 2020 19:32:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org C4B7F386F83E X-IronPort-AV: E=Sophos;i="5.75,282,1589241600"; d="scan'208";a="780331164" Received: from alln-core-8.cisco.com ([173.36.13.141]) by rcdn-iport-7.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 26 Jun 2020 19:32:34 +0000 Received: from zorba.cisco.com ([10.24.15.228]) by alln-core-8.cisco.com (8.15.2/8.15.2) with ESMTP id 05QJWSW4030756; Fri, 26 Jun 2020 19:32:29 GMT To: libc-alpha@sourceware.org Subject: [RFC PATCH 1/3] Segfault when dlopen with RTLD_GLOBAL in dlmopened library Date: Fri, 26 Jun 2020 12:32:26 -0700 Message-Id: <20200626193228.1953-2-danielwa@cisco.com> X-Mailer: git-send-email 2.17.1 X-Auto-Response-Suppress: DR, OOF, AutoReply X-Outbound-SMTP-Client: 10.24.15.228, [10.24.15.228] X-Outbound-Node: alln-core-8.cisco.com X-Spam-Status: No, score=-18.9 required=5.0 tests=BAYES_00, DKIMWL_WL_MED, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_PASS, SPF_PASS, TXREP, USER_IN_DEF_DKIM_WL 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: Daniel Walker via Libc-alpha From: Daniel Walker Reply-To: Daniel Walker Cc: Conan C Huang , Jeremy Stenglein , xe-linux-external@cisco.com Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" From: Conan C Huang GLIBC Bugzilla: 18684 When a dlmopenend library calls dlopen with RTLD_GLOBAL flag, dynamic loader segfaults. Loader is trying to add new linkmap into new namespaces _ns_main_searchlist. But this _ns_main_searchlist is not initialized during dmopen call (when namespace was created). Loader needs to initialize _ns_main_searchlist during dlmopen when a new namespace is created. As well as clean up when that namespace is deleted. --- elf/dl-close.c | 7 ++++++- elf/dl-open.c | 4 ++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/elf/dl-close.c b/elf/dl-close.c index 73b2817bbf..675f2fbac8 100644 --- a/elf/dl-close.c +++ b/elf/dl-close.c @@ -802,7 +802,12 @@ _dl_close_worker (struct link_map *map, bool force) if (__builtin_expect (ns->_ns_loaded == NULL, 0) && nsid == GL(dl_nns) - 1) do - --GL(dl_nns); + { + --GL(dl_nns); + + /* Clear main search list */ + GL(dl_ns)[GL(dl_nns)]._ns_main_searchlist = NULL; + } while (GL(dl_ns)[GL(dl_nns) - 1]._ns_loaded == NULL); /* Notify the debugger those objects are finalized and gone. */ diff --git a/elf/dl-open.c b/elf/dl-open.c index 8769e47051..9b3606c491 100644 --- a/elf/dl-open.c +++ b/elf/dl-open.c @@ -921,6 +921,10 @@ no more namespaces available for dlmopen()")); assert (_dl_debug_initialize (0, args.nsid)->r_state == RT_CONSISTENT); + /* Initialize main search list in new namespace */ + if (__glibc_unlikely (GL(dl_ns)[nsid]._ns_main_searchlist == NULL)) + GL(dl_ns)[nsid]._ns_main_searchlist = &(args.map->l_searchlist); + /* Release the lock. */ __rtld_lock_unlock_recursive (GL(dl_load_lock)); From patchwork Fri Jun 26 19:32:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Walker X-Patchwork-Id: 39807 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 07818388C030; Fri, 26 Jun 2020 19:32:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 07818388C030 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1593199960; bh=SphwH9CSYF5d5+SHoc56ayZE+Kwk/+1sRe6H9R5RX04=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:Cc:From; b=ZrsZQkRFzxZJB9M5vMk8vP7YiinSDVDkvL14/M90as8PmnpetfVrB4ysA5wimaWvW AkjNxkpcZ3oVyrUB9WidDB0dbEPHuKOdTSmwnCaJDgHAdMs3TS7+S/OUzQ4ODfbTSx PHxm0IFa4Eb/4kROuqp+FY9cX4yWS8iCxBcVI7jE= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from rcdn-iport-2.cisco.com (rcdn-iport-2.cisco.com [173.37.86.73]) by sourceware.org (Postfix) with ESMTPS id DE6973870854 for ; Fri, 26 Jun 2020 19:32:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org DE6973870854 X-IronPort-AV: E=Sophos;i="5.75,282,1589241600"; d="scan'208";a="793215497" Received: from alln-core-8.cisco.com ([173.36.13.141]) by rcdn-iport-2.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 26 Jun 2020 19:32:35 +0000 Received: from zorba.cisco.com ([10.24.15.228]) by alln-core-8.cisco.com (8.15.2/8.15.2) with ESMTP id 05QJWSW5030756; Fri, 26 Jun 2020 19:32:30 GMT To: libc-alpha@sourceware.org Subject: [RFC PATCH 2/3] glibc: dlopen RTLD_NOLOAD optimization Date: Fri, 26 Jun 2020 12:32:27 -0700 Message-Id: <20200626193228.1953-3-danielwa@cisco.com> X-Mailer: git-send-email 2.17.1 X-Auto-Response-Suppress: DR, OOF, AutoReply X-Outbound-SMTP-Client: 10.24.15.228, [10.24.15.228] X-Outbound-Node: alln-core-8.cisco.com X-Spam-Status: No, score=-17.4 required=5.0 tests=BAYES_00, DKIMWL_WL_MED, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_PASS, SPF_PASS, TXREP, USER_IN_DEF_DKIM_WL 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: Daniel Walker via Libc-alpha From: Daniel Walker Reply-To: Daniel Walker Cc: Conan C Huang , Jeremy Stenglein , xe-linux-external@cisco.com Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" From: Conan C Huang This is a fix for GLIBC Bugzilla #25615: dlopen RTLD_NOLOAD optimization When dlopen with RTLD_NOLOAD flag, loader should simply return the link_map or NULL and promote flags like RTLD_GLOBAL and RTLD_NODELETE. Loader shouldn't need to process any dependencies. In dl_open_worker, loader should avoid calling _dl_map_object_deps. _dl_map_object_deps is very time consuming on low-end platforms with lots of library dependencies. Loader retrains the same functionality during flag promotions: RTLD_GLOBAL RTLD_NODELETE https://sourceware.org/bugzilla/show_bug.cgi?id=25615 --- elf/dl-open.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/elf/dl-open.c b/elf/dl-open.c index 9b3606c491..cfef39ec53 100644 --- a/elf/dl-open.c +++ b/elf/dl-open.c @@ -542,7 +542,9 @@ dl_open_worker (void *a) ++new->l_direct_opencount; /* It was already open. */ - if (__glibc_unlikely (new->l_searchlist.r_list != NULL)) + if (__glibc_unlikely (new->l_searchlist.r_list != NULL) || + (__glibc_unlikely (mode & RTLD_NOLOAD) && + __glibc_unlikely (!(mode & RTLD_GLOBAL)))) { /* Let the user know about the opencount. */ if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES)) From patchwork Fri Jun 26 19:32:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Walker X-Patchwork-Id: 39808 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 F11BB388C03C; Fri, 26 Jun 2020 19:32:41 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org F11BB388C03C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1593199962; bh=mbYCkopn2k6PydWBW01day3Wie0S7QcfTbkcMurogpo=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:Cc:From; b=UqVh7Fv9SWVytOQ0d5qtcAuSRKP4WGPRRMDfCB1dhhhKHA4OO8RZZiqKkqAkudx5x 8Xs2v+gV4wu3OsdKdH0dp42iOGfBsbZvI9pzCuvxcj0phl/FMiHq8aN/nRcU7Li3PR XLOc9Z6u1EmtCj14UTb2qHkwJmdOBLNGG2G9syOU= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from rcdn-iport-5.cisco.com (rcdn-iport-5.cisco.com [173.37.86.76]) by sourceware.org (Postfix) with ESMTPS id 16C66386F83E for ; Fri, 26 Jun 2020 19:32:37 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 16C66386F83E X-IronPort-AV: E=Sophos;i="5.75,282,1589241600"; d="scan'208";a="528276816" Received: from alln-core-8.cisco.com ([173.36.13.141]) by rcdn-iport-5.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 26 Jun 2020 19:32:34 +0000 Received: from zorba.cisco.com ([10.24.15.228]) by alln-core-8.cisco.com (8.15.2/8.15.2) with ESMTP id 05QJWSW6030756; Fri, 26 Jun 2020 19:32:30 GMT To: libc-alpha@sourceware.org Subject: [RFC PATCH 3/3] add r_debug multiple namespaces support Date: Fri, 26 Jun 2020 12:32:28 -0700 Message-Id: <20200626193228.1953-4-danielwa@cisco.com> X-Mailer: git-send-email 2.17.1 X-Auto-Response-Suppress: DR, OOF, AutoReply X-Outbound-SMTP-Client: 10.24.15.228, [10.24.15.228] X-Outbound-Node: alln-core-8.cisco.com X-Spam-Status: No, score=-17.8 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_PASS, SPF_PASS, TXREP, USER_IN_DEF_DKIM_WL 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: Daniel Walker via Libc-alpha From: Daniel Walker Reply-To: Daniel Walker Cc: Conan C Huang , Jeremy Stenglein , xe-linux-external@cisco.com Errors-To: libc-alpha-bounces@sourceware.org Sender: "Libc-alpha" From: Conan C Huang GLIBC Bugzilla: 15971 GDB Bugzilla: 11839 Glibc does not provide an interface for debugger to access libraries loaded in multiple namespaces via dlmopen. The current rtld-debugger interface is described in the file elf/rtld-debugger-interface.txt under the "Standard debugger interface" heading. This interface only provides access to the first link-map (LM_ID_BASE). This solution converts r_debug into a linked-list, where each element correlates to an unique namespace. Debugger (GDB) can traverse r_debug linked-list to retrieve information for all loaded namespaces. --- elf/dl-debug.c | 13 ++++++++++--- elf/link.h | 4 ++++ 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/elf/dl-debug.c b/elf/dl-debug.c index 4b3d3ad6ba..7eba477fd3 100644 --- a/elf/dl-debug.c +++ b/elf/dl-debug.c @@ -44,20 +44,27 @@ struct r_debug _r_debug; struct r_debug * _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns) { - struct r_debug *r; + struct r_debug *r, *rp; if (ns == LM_ID_BASE) r = &_r_debug; else - r = &GL(dl_ns)[ns]._ns_debug; + { + r = &GL(dl_ns)[ns]._ns_debug; + rp = &GL(dl_ns)[ns - 1]._ns_debug; + rp->next = r; + if (ns - 1 == LM_ID_BASE) + _r_debug.next = r; + } if (r->r_map == NULL || ldbase != 0) { /* Tell the debugger where to find the map of loaded objects. */ - r->r_version = 1 /* R_DEBUG_VERSION XXX */; + r->r_version = 3 /* R_DEBUG_VERSION XXX */; r->r_ldbase = ldbase ?: _r_debug.r_ldbase; r->r_map = (void *) GL(dl_ns)[ns]._ns_loaded; r->r_brk = (ElfW(Addr)) &_dl_debug_state; + r->next = NULL; } return r; diff --git a/elf/link.h b/elf/link.h index 0048ad5d4d..5a42511636 100644 --- a/elf/link.h +++ b/elf/link.h @@ -61,6 +61,10 @@ struct r_debug } r_state; ElfW(Addr) r_ldbase; /* Base address the linker is loaded at. */ + + /* Link to next r_debug struct. Each r_debug struct represents a + different namespace. The first r_debug struct is the default. */ + struct r_debug *next; }; /* This is the instance of that structure used by the dynamic linker. */