From patchwork Thu Oct 14 17:47:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella X-Patchwork-Id: 46238 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 CE8703858015 for ; Thu, 14 Oct 2021 17:59:23 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CE8703858015 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1634234363; bh=FilIzGk9l/X2Djq3lJXR0xf/6u/GYQbYTqZEjkWE/rk=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=li6vx7pBa3Xw/Nxw8hcIp8e401Kr3cpw6nWElMfcEPxHCRQJI1qIWvkXR8SOQVkFm 3r0q9/THQCX/7X2k9nWlv0hCJlWPTIYq+LLvUcff30fz/7uh4x5Biw3WMkgq4xbR5z OFXamzgYyDvaUW8MHLAhBgY2Gttgb0yaMFihLbhc= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-ua1-x92c.google.com (mail-ua1-x92c.google.com [IPv6:2607:f8b0:4864:20::92c]) by sourceware.org (Postfix) with ESMTPS id 28BB63857C53 for ; Thu, 14 Oct 2021 17:48:22 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 28BB63857C53 Received: by mail-ua1-x92c.google.com with SMTP id h4so12976597uaw.1 for ; Thu, 14 Oct 2021 10:48:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=FilIzGk9l/X2Djq3lJXR0xf/6u/GYQbYTqZEjkWE/rk=; b=FIV8e82Drnplya01CRgeqr3wYQ3mvG+9kXXbpGwEDPTmDS/TXVUiAUzujoTgiFPGly X7fALaSnkbi3/Zqs01b/vgnNpGCo4qz4nEG3vQwBG9TJbH1221nipK8HSZcRW2zpi9nj nxsn1tsB2wN0mPuIaAkERqyuhbGsNUWMtQ12QJyUjW0ym57gts8IxIaGtVEGTpuPUFkg am5dfIkN16MtYKLq3bYxR1ZUrASv5t7hiP0EOuQn8pY2lotorMef5sZZ/lP3fUZkML9I O6AGTywG+LcGkpUWB/bUxG4PFqoewpxrc/JfhaYRnFXRgFFHBc3StSBrU8AY5fEOpoLd gbQw== X-Gm-Message-State: AOAM531PAnPdUCF5veNHCQ4qILe1oZGC271ZLRabPr3C1vDKNgbld6mm 8t7whEJlOezF0KEGGkLemc30pGsFLdQOiA== X-Google-Smtp-Source: ABdhPJxoljFkCJ5gnAgLBfO9IAtVTMNxpXXETngA2J4cpKuoG1tYQskmUSq9BPsiiwgBm5/EXwAVNw== X-Received: by 2002:ab0:30b3:: with SMTP id b19mr8109422uam.123.1634233701514; Thu, 14 Oct 2021 10:48:21 -0700 (PDT) Received: from birita.. ([2804:431:c7ca:c6c7:3c65:db0e:6fcc:a8e9]) by smtp.gmail.com with ESMTPSA id q26sm2107237vkn.40.2021.10.14.10.48.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Oct 2021 10:48:21 -0700 (PDT) To: libc-alpha@sourceware.org Subject: [PATCH v4 15/21] elf: Add main application on main_map l_name Date: Thu, 14 Oct 2021 14:47:46 -0300 Message-Id: <20211014174752.1651347-16-adhemerval.zanella@linaro.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211014174752.1651347-1-adhemerval.zanella@linaro.org> References: <20211014174752.1651347-1-adhemerval.zanella@linaro.org> MIME-Version: 1.0 X-Spam-Status: No, score=-12.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: Adhemerval Zanella via Libc-alpha From: Adhemerval Zanella Reply-To: Adhemerval Zanella Cc: John Mellor-Crummey Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" For the la_objopen() the path listed in link_map->l_name for the main application binary is empty, even though dladdr() is able to recover the correct path. By setting the expected application name on l_name, it allows to simplify the code to handle the special case and make the API that return such information (la_objopen(), dladdr() and dlinfo() to have similar semantic. Checked on x86_64-linux-gnu. --- dlfcn/Makefile | 4 ++- dlfcn/tst-dladdr-self.c | 55 +++++++++++++++++++++++++++++++++++++++++ elf/dl-addr.c | 5 ---- elf/dl-dst.h | 2 +- elf/dl-init.c | 3 +-- elf/dl-load.c | 9 +++++-- elf/dl-misc.c | 1 + elf/rtld.c | 6 +---- elf/tst-audit22.c | 4 +++ elf/tst-auditmod22.c | 8 ++++++ gmon/gmon.c | 10 ++++---- 11 files changed, 86 insertions(+), 21 deletions(-) create mode 100644 dlfcn/tst-dladdr-self.c diff --git a/dlfcn/Makefile b/dlfcn/Makefile index 6bbfbb8344..bceb2b2885 100644 --- a/dlfcn/Makefile +++ b/dlfcn/Makefile @@ -51,7 +51,7 @@ endif ifeq (yes,$(build-shared)) tests = glrefmain failtest tst-dladdr default errmsg1 tstcxaatexit \ bug-dlopen1 bug-dlsym1 tst-dlinfo bug-atexit1 bug-atexit2 \ - bug-atexit3 tstatexit bug-dl-leaf tst-rec-dlopen + bug-atexit3 tstatexit bug-dl-leaf tst-rec-dlopen tst-dladdr-self endif modules-names = glreflib1 glreflib2 glreflib3 failtestmod defaultmod1 \ defaultmod2 errmsg1mod modatexit modcxaatexit \ @@ -143,3 +143,5 @@ $(objpfx)bug-dl-leaf.out: $(objpfx)bug-dl-leaf-lib-cb.so $(objpfx)bug-dl-leaf-lib-cb.so: $(objpfx)bug-dl-leaf-lib.so $(objpfx)tst-rec-dlopen.out: $(objpfx)moddummy1.so $(objpfx)moddummy2.so + +LDFLAGS-tst-dladdr-self = -rdynamic diff --git a/dlfcn/tst-dladdr-self.c b/dlfcn/tst-dladdr-self.c new file mode 100644 index 0000000000..0eddaf1cd7 --- /dev/null +++ b/dlfcn/tst-dladdr-self.c @@ -0,0 +1,55 @@ +/* Check dladdr with the reference to own exectuable. + Copyright (C) 2021 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 +#include + +void +test_symbol (void) +{ +} + +static int +do_test (void) +{ + void *handle = xdlopen (NULL, RTLD_NOW); + int (*sym)(void) = xdlsym (handle, "test_symbol"); + + Dl_info info = { 0 }; + { + int r = dladdr (sym, &info); + TEST_VERIFY_EXIT (r != 0); + } + + { + const char *p = strrchr (info.dli_fname, '/'); + const char *dli_name = p == NULL ? info.dli_fname : p + 1; + + TEST_COMPARE_STRING (dli_name, "tst-dladdr-self"); + } + + TEST_COMPARE_STRING (info.dli_sname, "test_symbol"); + TEST_COMPARE ((uintptr_t) info.dli_saddr, (uintptr_t) test_symbol); + + return 0; +} + +#include diff --git a/elf/dl-addr.c b/elf/dl-addr.c index 3226880d48..c2c93c63ad 100644 --- a/elf/dl-addr.c +++ b/elf/dl-addr.c @@ -30,11 +30,6 @@ determine_info (const ElfW(Addr) addr, struct link_map *match, Dl_info *info, info->dli_fname = match->l_name; info->dli_fbase = (void *) match->l_map_start; - /* If this is the main program the information is incomplete. */ - if (__builtin_expect (match->l_name[0], 'a') == '\0' - && match->l_type == lt_executable) - info->dli_fname = _dl_argv[0]; - const ElfW(Sym) *symtab = (const ElfW(Sym) *) D_PTR (match, l_info[DT_SYMTAB]); const char *strtab = (const char *) D_PTR (match, l_info[DT_STRTAB]); diff --git a/elf/dl-dst.h b/elf/dl-dst.h index 34bbaf65dc..a1e9af5a06 100644 --- a/elf/dl-dst.h +++ b/elf/dl-dst.h @@ -44,7 +44,7 @@ auditing, in ld.so. */ \ if ((l)->l_origin == NULL) \ { \ - assert ((l)->l_name[0] == '\0' || IS_RTLD (l)); \ + assert ((l)->l_type == lt_executable || IS_RTLD (l)); \ (l)->l_origin = _dl_get_origin (); \ dst_len = ((l)->l_origin && (l)->l_origin != (char *) -1 \ ? strlen ((l)->l_origin) : 0); \ diff --git a/elf/dl-init.c b/elf/dl-init.c index f924d26642..9fa8403290 100644 --- a/elf/dl-init.c +++ b/elf/dl-init.c @@ -39,8 +39,7 @@ call_init (struct link_map *l, int argc, char **argv, char **env) l->l_init_called = 1; /* Check for object which constructors we do not run here. */ - if (__builtin_expect (l->l_name[0], 'a') == '\0' - && l->l_type == lt_executable) + if (l->l_type == lt_executable) return; /* Print a debug message if wanted. */ diff --git a/elf/dl-load.c b/elf/dl-load.c index 90de8e0061..0c7a659c13 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1996,13 +1996,18 @@ _dl_map_object (struct link_map *loader, const char *name, assert (nsid >= 0); assert (nsid < GL(dl_nns)); + /* Special case: trying to map itself. */ + if (name[0] == '\0') + return GL(dl_ns)[nsid]._ns_loaded; + /* Look for this name among those already loaded. */ for (l = GL(dl_ns)[nsid]._ns_loaded; l; l = l->l_next) { /* If the requested name matches the soname of a loaded object, use that object. Elide this check for names that have not - yet been opened. */ - if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0)) + yet been opened or the executable itself. */ + if (__glibc_unlikely ((l->l_faked | l->l_removed + || l->l_type == lt_executable) != 0)) continue; if (!_dl_name_match_p (name, l)) { diff --git a/elf/dl-misc.c b/elf/dl-misc.c index b256d792c6..b62bbcb8b4 100644 --- a/elf/dl-misc.c +++ b/elf/dl-misc.c @@ -338,6 +338,7 @@ rtld_hidden_def (_dl_fatal_printf) int _dl_name_match_p (const char *name, const struct link_map *map) { + /* Filter out the main executable. */ if (strcmp (name, map->l_name) == 0) return 1; diff --git a/elf/rtld.c b/elf/rtld.c index 7f559b1aa7..404c7ff041 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1360,11 +1360,6 @@ dl_main (const ElfW(Phdr) *phdr, phdr = main_map->l_phdr; phnum = main_map->l_phnum; - /* We overwrite here a pointer to a malloc()ed string. But since - the malloc() implementation used at this point is the dummy - implementations which has no real free() function it does not - makes sense to free the old string first. */ - main_map->l_name = (char *) ""; *user_entry = main_map->l_entry; #ifdef HAVE_AUX_VECTOR @@ -1427,6 +1422,7 @@ dl_main (const ElfW(Phdr) *phdr, information for the program. */ } + main_map->l_name = _dl_argv[0]; main_map->l_map_end = 0; main_map->l_text_end = 0; /* Perhaps the executable has no PT_LOAD header entries at all. */ diff --git a/elf/tst-audit22.c b/elf/tst-audit22.c index c1b301c4cc..7718e3e959 100644 --- a/elf/tst-audit22.c +++ b/elf/tst-audit22.c @@ -94,6 +94,7 @@ do_test (int argc, char *argv[]) unsigned long vdso_process = 0; unsigned long vdso_audit = 0; + bool mainapp_found = false; FILE *out = fmemopen (result.err.buffer, result.err.length, "r"); TEST_VERIFY (out != NULL); @@ -105,9 +106,12 @@ do_test (int argc, char *argv[]) vdso_process = parse_address (buffer + strlen ("vdso: ")); else if (startswith (buffer, "vdso found: ")) vdso_audit = parse_address (buffer + strlen ("vdso found: ")); + else if (startswith (buffer, "mainapp found")) + mainapp_found = true; } TEST_COMPARE (vdso_process, vdso_audit); + TEST_COMPARE (mainapp_found, true); free (buffer); xfclose (out); diff --git a/elf/tst-auditmod22.c b/elf/tst-auditmod22.c index 02275bed57..a4921f35de 100644 --- a/elf/tst-auditmod22.c +++ b/elf/tst-auditmod22.c @@ -19,6 +19,7 @@ #include #include #include +#include #include unsigned int @@ -30,6 +31,13 @@ la_version (unsigned int version) unsigned int la_objopen (struct link_map *map, Lmid_t lmid, uintptr_t *cookie) { + { + const char *p = strrchr (map->l_name, '/'); + const char *l_name = p == NULL ? map->l_name : p + 1; + if (strcmp (l_name, "tst-audit22") == 0) + fprintf (stderr, "mainapp found\n"); + } + if (map->l_addr == getauxval (AT_SYSINFO_EHDR)) fprintf (stderr, "vdso found: %" PRIxPTR "\n", (uintptr_t) map->l_addr); diff --git a/gmon/gmon.c b/gmon/gmon.c index dee64803ad..cb8327b8e4 100644 --- a/gmon/gmon.c +++ b/gmon/gmon.c @@ -48,16 +48,16 @@ #ifdef PIC # include +# include static int callback (struct dl_phdr_info *info, size_t size, void *data) { - if (info->dlpi_name[0] == '\0') + if (info->dlpi_name == _dl_argv[0]) { - /* The link map for the executable is created by calling - _dl_new_object with "" as filename. dl_iterate_phdr - calls the callback function with filename from the - link map as dlpi_name. */ + /* The link map l_name for the executable is set to the _dl_argv[0] + after argument processing. dl_iterate_phdr() calls the callback + function with filename from the link map as dlpi_name. */ u_long *load_address = data; *load_address = (u_long) info->dlpi_addr; return 1;