From patchwork Tue Feb 9 14:31:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 580869 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 75CC814030F for ; Wed, 10 Feb 2016 01:31:34 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b=UXGjG5ul; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:to:from:subject:message-id:date:mime-version :content-type; q=dns; s=default; b=AhDqQUWWfEsu2QK1YA02tkxFOW+KF 574CSrfxdbGj+KIvibJ3d4WxyQzlBS9Jlh8O6a5MSc07tidKhAfqIfMJOku+ZxsD DnPnEjyYyx/Npf23Fwar395l+9D6ci/4ELfxU8mNDLcNQTgQ46UKuvIgiwI6g9Hl Y5kVgdxte5SGuc= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:to:from:subject:message-id:date:mime-version :content-type; s=default; bh=lO49EHObFFIqVWYGKVHv0ILgEdA=; b=UXG jG5ulzViYzpFgv6kRmv7jjFxqqtvBX+o6f9Hwc7uQpLpBH/p+koBnE/Llk9b3roZ TjdJgBliplJ7gsJvdLqEEF5vlP5qDuHgH3MDJl2EQ/lA1iTMwu6vQ/mY3jjsFmZN Kxv5rOiioHuJxK+gOi6qZeKrs4EAn8WPGkRVD2G0= Received: (qmail 79181 invoked by alias); 9 Feb 2016 14:31:28 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 79171 invoked by uid 89); 9 Feb 2016 14:31:28 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=BAYES_00, RP_MATCHES_RCVD, SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=conservative, 1497, 149, 7, 1106 X-HELO: mx1.redhat.com To: GNU C Library From: Florian Weimer Subject: [PATCH] Report dlsym, dlvsym lookup errors using dlerror [BZ #19509] X-Enigmail-Draft-Status: N1110 Message-ID: <56B9F83A.1000500@redhat.com> Date: Tue, 9 Feb 2016 15:31:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 I'm not sure if this is the right fix. I traced back the lack of error reporting to the original addition of the RTLD_NEXT functionality. I don't know why it was omitted from it. I could not find any callers of _dl_lookup_symbol_x which with skip_map != NULL and which are not related to RTLD_NEXT, so this change looks pretty conservative to me. Florian 2016-02-09 Florian Weimer [BZ #19509] * elf/dl-lookup.c (_dl_lookup_symbol_x): Report error even if skip_map != NULL. * elf/bug19509.c: New file. * elf/Makefile (tests): Add bug19509. (bug19509): Link against libdl. diff --git a/elf/Makefile b/elf/Makefile index 63a5355..18baa23 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -149,7 +149,8 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \ tst-nodelete) \ tst-initorder tst-initorder2 tst-relsort1 tst-null-argv \ tst-ptrguard1 tst-tlsalign tst-tlsalign-extern tst-nodelete-opened \ - tst-nodelete2 tst-audit11 tst-audit12 + tst-nodelete2 tst-audit11 tst-audit12 \ + bug19509 # reldep9 ifeq ($(build-hardcoded-path-in-tests),yes) tests += tst-dlopen-aout @@ -1252,3 +1253,5 @@ $(objpfx)tst-prelink-cmp.out: tst-prelink.exp \ $(objpfx)tst-prelink-conflict.out cmp $^ > $@; \ $(evaluate-test) + +$(objpfx)bug19509: $(libdl) diff --git a/elf/bug19509.c b/elf/bug19509.c new file mode 100644 index 0000000..e7ccf88 --- /dev/null +++ b/elf/bug19509.c @@ -0,0 +1,106 @@ +/* Test error reporting for dlsym, dlvsym failures. + Copyright (C) 2016 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 +#include +#include + +/* Used to disambiguate symbol names. */ +static int counter; + +static void +test_one (void *handle, const char *name, void *(func) (void *, const char *), + const char *suffix) +{ + ++counter; + char symbol[32]; + snprintf (symbol, sizeof (symbol), "no_such_symbol_%d", counter); + char *expected_message; + if (asprintf (&expected_message, ": undefined symbol: %s%s", + symbol, suffix) < 0) + { + printf ("error: asprintf: %m\n"); + abort (); + } + + void *addr = func (handle, symbol); + if (addr != NULL) + { + printf ("error: %s: found symbol \"no_such_symbol\"\n", name); + abort (); + } + const char *message = dlerror (); + if (message == NULL) + { + printf ("error: %s: missing error message\n", name); + abort (); + } + const char *message_without_path = strchrnul (message, ':'); + if (strcmp (message_without_path, expected_message) != 0) + { + printf ("error: %s: unexpected error message: %s\n", name, message); + abort (); + } + free (expected_message); +} + +static void +test_handles (const char *name, void *(func) (void *, const char *), + const char *suffix) +{ + test_one (RTLD_DEFAULT, name, func, suffix); + test_one (RTLD_NEXT, name, func, suffix); + + void *handle = dlopen (LIBC_SO, RTLD_LAZY); + if (handle == NULL) + { + printf ("error: cannot dlopen %s: %s\n", LIBC_SO, dlerror ()); + abort (); + } + test_one (handle, name, func, suffix); + dlclose (handle); +} + +static void * +dlvsym_no_such_version (void *handle, const char *name) +{ + return dlvsym (handle, name, "NO_SUCH_VERSION"); +} + +static void * +dlvsym_glibc_private (void *handle, const char *name) +{ + return dlvsym (handle, name, "GLIBC_PRIVATE"); +} + +static int +do_test (void) +{ + test_handles ("dlsym", dlsym, ""); + test_handles ("dlvsym", dlvsym_no_such_version, + ", version NO_SUCH_VERSION"); + test_handles ("dlvsym", dlvsym_glibc_private, + ", version GLIBC_PRIVATE"); + + return 0; +} + + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index f577759..6d299c1 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -858,7 +858,6 @@ _dl_lookup_symbol_x (const char *undef_name, struct link_map *undef_map, if (__glibc_unlikely (current_value.s == NULL)) { if ((*ref == NULL || ELFW(ST_BIND) ((*ref)->st_info) != STB_WEAK) - && skip_map == NULL && !(GLRO(dl_debug_mask) & DL_DEBUG_UNUSED)) { /* We could find no value for a strong reference. */ -- 2.4.3