[PATCH 08/10] elf: Do not load libpthread for PTHREAD_IN_LIBC

[Florian Weimer <fweimer@redhat.com>]

---
 elf/dl-load.c    | 19 +++++++++++++++++--
 elf/dl-version.c |  9 +++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/elf/dl-load.c b/elf/dl-load.c
index 918ec7546c..f97cb140f4 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -2029,12 +2029,26 @@ open_path (const char *name, size_t namelen, int mode,
 
 /* Map in the shared object file NAME.  */
 
+static inline const char *
+object_real_name (const char *name)
+{
+  /* If libpthread is integrated into libc, treat a request to load
+     libpthread as a request to load libc (because libc was a
+     dependency of libpthread).  */
+#if PTHREAD_IN_LIBC
+  if (strcmp (name, LIBPTHREAD_SO) == 0)
+    return LIBC_SO;
+#endif
+  return name;
+}
+
 struct link_map *
 _dl_map_object (struct link_map *loader, const char *name,
 		int type, int trace_mode, int mode, Lmid_t nsid)
 {
   int fd;
   const char *origname = NULL;
+  const char *implementation_name = object_real_name (name);
   char *realname;
   char *name_copy;
   struct link_map *l;
@@ -2051,7 +2065,7 @@ _dl_map_object (struct link_map *loader, const char *name,
 	 yet been opened.  */
       if (__glibc_unlikely ((l->l_faked | l->l_removed) != 0))
 	continue;
-      if (!_dl_name_match_p (name, l))
+      if (!_dl_name_match_p (implementation_name, l))
 	{
 	  const char *soname;
 
@@ -2061,7 +2075,7 @@ _dl_map_object (struct link_map *loader, const char *name,
 
 	  soname = ((const char *) D_PTR (l, l_info[DT_STRTAB])
 		    + l->l_info[DT_SONAME]->d_un.d_val);
-	  if (strcmp (name, soname) != 0)
+	  if (strcmp (implementation_name, soname) != 0)
 	    continue;
 
 	  /* We have a match on a new name -- cache it.  */
@@ -2106,6 +2120,7 @@ _dl_map_object (struct link_map *loader, const char *name,
 		  if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
 		    _dl_debug_printf ("audit changed filename %s -> %s\n",
 				      before, name);
+		  implementation_name = object_real_name (name);
 
 		  if (origname == NULL)
 		    origname = before;
diff --git a/elf/dl-version.c b/elf/dl-version.c
index 914955c2a8..932cffda09 100644
--- a/elf/dl-version.c
+++ b/elf/dl-version.c
@@ -24,6 +24,7 @@
 #include <string.h>
 #include <ldsodefs.h>
 #include <_itoa.h>
+#include <gnu/lib-names.h>
 
 #include <assert.h>
 
@@ -200,6 +201,14 @@ _dl_check_map_versions (struct link_map *map, int verbose, int trace_mode)
 	  ElfW(Vernaux) *aux;
 	  struct link_map *needed = find_needed (strtab + ent->vn_file, map);
 
+#if PTHREAD_IN_LIBC
+	  /* With an integrated libpthread, check libpthread
+	     references against libc instead.  */
+	  if (needed == NULL
+	      && strcmp (strtab + ent->vn_file, LIBPTHREAD_SO) == 0)
+	    needed = find_needed (LIBC_SO, map);
+#endif
+
 	  /* If NEEDED is NULL this means a dependency was not found
 	     and no stub entry was created.  This should never happen.  */
 	  assert (needed != NULL);
-- 
2.31.1