From patchwork Tue Jun 26 18:05:42 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 28058 Received: (qmail 100554 invoked by alias); 26 Jun 2018 18:05:46 -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 100540 invoked by uid 89); 26 Jun 2018 18:05:46 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=4388 X-HELO: mx1.redhat.com Date: Tue, 26 Jun 2018 20:05:42 +0200 To: libc-alpha@sourceware.org Subject: [PATCH] _dl_map_object_deps: Use struct scratch_buffer [BZ #18023] User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Message-Id: <20180626180542.5AAAD43994575@oldenburg.str.redhat.com> From: fweimer@redhat.com (Florian Weimer) The function comment suggests that _dl_map_object_deps cannot use malloc, but it already allocates the l_initfini array on the heap, so the additional allocation should be acceptable. 2018-06-26 Florian Weimer [BZ #18023] * elf/dl-deps.c (_dl_map_object_deps): Use struct scratch_buffer instead of extend_alloca. Reviewed-by: Carlos O'Donell diff --git a/elf/dl-deps.c b/elf/dl-deps.c index 20b8e94f2e..9d9b1ba7f2 100644 --- a/elf/dl-deps.c +++ b/elf/dl-deps.c @@ -27,6 +27,7 @@ #include #include #include +#include #include @@ -181,9 +182,8 @@ _dl_map_object_deps (struct link_map *map, /* Pointer to last unique object. */ tail = &known[nlist - 1]; - /* No alloca'd space yet. */ - struct link_map **needed_space = NULL; - size_t needed_space_bytes = 0; + struct scratch_buffer needed_space; + scratch_buffer_init (&needed_space); /* Process each element of the search list, loading each of its auxiliary objects and immediate dependencies. Auxiliary objects @@ -213,13 +213,12 @@ _dl_map_object_deps (struct link_map *map, if (l->l_searchlist.r_list == NULL && l->l_initfini == NULL && l != map && l->l_ldnum > 0) { - size_t new_size = l->l_ldnum * sizeof (struct link_map *); - - if (new_size > needed_space_bytes) - needed_space - = extend_alloca (needed_space, needed_space_bytes, new_size); - - needed = needed_space; + /* l->l_ldnum includes space for the terminating NULL. */ + if (!scratch_buffer_set_array_size + (&needed_space, l->l_ldnum, sizeof (struct link_map *))) + _dl_signal_error (ENOMEM, map->l_name, NULL, + N_("cannot allocate dependency buffer")); + needed = needed_space.data; } if (l->l_info[DT_NEEDED] || l->l_info[AUXTAG] || l->l_info[FILTERTAG]) @@ -438,8 +437,11 @@ _dl_map_object_deps (struct link_map *map, struct link_map **l_initfini = (struct link_map **) malloc ((2 * nneeded + 1) * sizeof needed[0]); if (l_initfini == NULL) - _dl_signal_error (ENOMEM, map->l_name, NULL, - N_("cannot allocate dependency list")); + { + scratch_buffer_free (&needed_space); + _dl_signal_error (ENOMEM, map->l_name, NULL, + N_("cannot allocate dependency list")); + } l_initfini[0] = l; memcpy (&l_initfini[1], needed, nneeded * sizeof needed[0]); memcpy (&l_initfini[nneeded + 1], l_initfini, @@ -457,6 +459,8 @@ _dl_map_object_deps (struct link_map *map, } out: + scratch_buffer_free (&needed_space); + if (errno == 0 && errno_saved != 0) __set_errno (errno_saved);