diff options
Diffstat (limited to 'elf/rtld.c')
| -rw-r--r-- | elf/rtld.c | 47 |
1 files changed, 45 insertions, 2 deletions
@@ -21,6 +21,7 @@ Cambridge, MA 02139, USA. */ #include <stddef.h> #include <stdlib.h> #include <unistd.h> +#include <sys/mman.h> /* Check if MAP_ANON is defined. */ #include "../stdio-common/_itoa.h" @@ -124,6 +125,8 @@ dl_main (const ElfW(Phdr) *phdr, struct link_map *l; int lazy; int list_only = 0; + struct link_map **preloads; + unsigned int npreloads; if (*user_entry == (ElfW(Addr)) &_start) { @@ -247,12 +250,52 @@ of this helper program; chances are you did not intend to run this program.\n", l->l_next = &_dl_rtld_map; _dl_rtld_map.l_prev = l; - /* Load all the libraries specified by DT_NEEDED entries. */ - _dl_map_object_deps (l); + preloads = NULL; + npreloads = 0; + if (! _dl_secure) + { + const char *preloadlist = getenv ("LD_PRELOAD"); + if (preloadlist) + { + /* The LD_PRELOAD environment variable gives a colon-separated + list of libraries that are loaded before the executable's + dependencies and prepended to the global scope list. */ + char *list = strdupa (preloadlist); + char *p; + while ((p = strsep (&list, ":")) != NULL) + { + (void) _dl_map_object (NULL, p, lt_library); + ++npreloads; + } + + if (npreloads != 0) + { + /* Set up PRELOADS with a vector of the preloaded libraries. */ + struct link_map *l; + unsigned int i; + preloads = __alloca (npreloads * sizeof preloads[0]); + l = _dl_rtld_map.l_next; /* End of the chain before preloads. */ + i = 0; + do + { + preloads[i++] = l; + l = l->l_next; + } while (l); + assert (i == npreloads); + } + } + } + + /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD + specified some libraries to load, these are inserted before the actual + dependencies in the executable's searchlist for symbol resolution. */ + _dl_map_object_deps (l, preloads, npreloads); +#ifndef MAP_ANON /* We are done mapping things, so close the zero-fill descriptor. */ __close (_dl_zerofd); _dl_zerofd = -1; +#endif /* Remove _dl_rtld_map from the chain. */ _dl_rtld_map.l_prev->l_next = _dl_rtld_map.l_next; |