[PATCH 2/2] malloc: Use __libc_type to detect an inner libc

[Florian Weimer <fweimer@redhat.com>]

The inner libc must not use sbrk.  _dl_addr occasionally shows up
in profiles, but had to be used before because __libc_multiple_libs
was unreliable.
---
 malloc/arena.c  | 7 +------
 malloc/malloc.c | 2 ++
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/malloc/arena.c b/malloc/arena.c
index 202daf15b0..865eaa1a84 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -296,12 +296,7 @@ ptmalloc_init (void)
 #ifdef SHARED
   /* In case this libc copy is in a non-default namespace, never use brk.
      Likewise if dlopened from statically linked program.  */
-  Dl_info di;
-  struct link_map *l;
-
-  if (_dl_open_hook != NULL
-      || (_dl_addr (ptmalloc_init, &di, &l, NULL) != 0
-          && l->l_ns != LM_ID_BASE))
+  if (__libc_type == libc_type_secondary)
     __morecore = __failing_morecore;
 #endif
 
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 5b87bdb081..0834e4181a 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -247,6 +247,8 @@
 /* For SINGLE_THREAD_P.  */
 #include <sysdep-cancel.h>
 
+#include <libc-internal.h>
+
 /*
   Debugging:
 
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