From ccdb048df457d581f6ac7ede8b0c7a593a891dfa Mon Sep 17 00:00:00 2001 From: Carlos O'Donell Date: Wed, 21 Jan 2015 01:51:10 -0500 Subject: Fix recursive dlopen. The ability to recursively call dlopen is useful for malloc implementations that wish to load other dynamic modules that implement reentrant/AS-safe functions to use in their own implementation. Given that a user malloc implementation may be called by an ongoing dlopen to allocate memory the user malloc implementation interrupts dlopen and if it calls dlopen again that's a reentrant call. This patch fixes the issues with the ld.so.cache mapping and the _r_debug assertion which prevent this from working as expected. See: https://sourceware.org/ml/libc-alpha/2014-12/msg00446.html --- elf/dl-load.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) (limited to 'elf/dl-load.c') diff --git a/elf/dl-load.c b/elf/dl-load.c index d6726b627f..73174aa424 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -2051,7 +2051,7 @@ _dl_map_object (struct link_map *loader, const char *name, { /* Check the list of libraries in the file /etc/ld.so.cache, for compatibility with Linux's ldconfig program. */ - const char *cached = _dl_load_cache_lookup (name); + char *cached = _dl_load_cache_lookup (name); if (cached != NULL) { @@ -2075,6 +2075,7 @@ _dl_map_object (struct link_map *loader, const char *name, if (memcmp (cached, dirp, system_dirs_len[cnt]) == 0) { /* The prefix matches. Don't use the entry. */ + free (cached); cached = NULL; break; } @@ -2092,14 +2093,9 @@ _dl_map_object (struct link_map *loader, const char *name, LA_SER_CONFIG, mode, &found_other_class, false); if (__glibc_likely (fd != -1)) - { - realname = __strdup (cached); - if (realname == NULL) - { - __close (fd); - fd = -1; - } - } + realname = cached; + else + free (cached); } } } -- cgit 1.4.1