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

1 files changed, 3 insertions, 1 deletions

diff --git a/elf/dl-open.c b/elf/dl-open.c
index c358fff900..47b4cb500a 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -217,7 +217,9 @@ dl_open_worker (void *a)
 	args->nsid = call_map->l_ns;
     }
 
-  assert (_dl_debug_initialize (0, args->nsid)->r_state == RT_CONSISTENT);
+  /* One might be tempted to assert that we are RT_CONSISTENT at this point, but that
+     may not be true if this is a recursive call to dlopen.  */
+  _dl_debug_initialize (0, args->nsid);
 
   /* Load the named object.  */
   struct link_map *new;