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-rw-r--r--elf/rtld.c31
1 files changed, 22 insertions, 9 deletions
diff --git a/elf/rtld.c b/elf/rtld.c
index 23e0d35d78..d727e1361f 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -339,23 +339,36 @@ of this helper program; chances are you did not intend to run this program.\n",
lazy = !_dl_secure && *(getenv ("LD_BIND_NOW") ?: "") == '\0';
- /* Do any necessary cleanups for the startup OS interface code.
- We do these now so that no calls are made after real relocation
- which might be resolved to different functions than we expect. */
- _dl_sysdep_start_cleanup ();
-
- /* Now we have all the objects loaded. Relocate them all.
- We do this in reverse order so that copy relocs of earlier
- objects overwrite the data written by later objects. */
+ /* Now we have all the objects loaded. Relocate them all except for
+ the dynamic linker itself. We do this in reverse order so that
+ copy relocs of earlier objects overwrite the data written by later
+ objects. We do not re-relocate the dynamic linker itself in this
+ loop because that could result in the GOT entries for functions we
+ call being changed, and that would break us. It is safe to
+ relocate the dynamic linker out of order because it has no copy
+ relocs (we know that because it is self-contained). */
l = _dl_loaded;
while (l->l_next)
l = l->l_next;
do
{
- _dl_relocate_object (l, lazy);
+ if (l != &rtld_map)
+ _dl_relocate_object (l, lazy);
l = l->l_prev;
} while (l);
+ /* Do any necessary cleanups for the startup OS interface code.
+ We do these now so that no calls are made after rtld re-relocation
+ which might be resolved to different functions than we expect.
+ We cannot do this before relocating the other objects because
+ _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */
+ _dl_sysdep_start_cleanup ();
+
+ if (rtld_map.l_opencount > 0)
+ /* There was an explicit ref to the dynamic linker as a shared lib.
+ Re-relocate ourselves with user-controlled symbol definitions. */
+ _dl_relocate_object (&rtld_map, lazy);
+
/* Tell the debugger where to find the map of loaded objects. */
dl_r_debug.r_version = 1 /* R_DEBUG_VERSION XXX */;
dl_r_debug.r_ldbase = rtld_map.l_addr; /* Record our load address. */