dlfcn: Do not use rtld_active () to determine ld.so state (bug 29078)

When audit modules are loaded, ld.so initialization is not yet
complete, and rtld_active () returns false even though ld.so is
mostly working.  Instead, the static dlopen hook is used, but that
does not work at all because this is not a static dlopen situation.

Commit 466c1ea15f461edb8e3ffaf5d86d708876343bbf ("dlfcn: Rework
static dlopen hooks") moved the hook pointer into _rtld_global_ro,
which means that separate protection is not needed anymore and the
hook pointer can be checked directly.

The guard for disabling libio vtable hardening in _IO_vtable_check
should stay for now.

Fixes commit 8e1472d2c1e25e6eabc2059170731365f6d5b3d1 ("ld.so:
Examine GLRO to detect inactive loader [BZ #20204]").

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

10 files changed, 10 insertions, 10 deletions

diff --git a/dlfcn/dladdr.c b/dlfcn/dladdr.c
index ead1173..d188d0e 100644
--- a/dlfcn/dladdr.c
+++ b/dlfcn/dladdr.c
@@ -24,7 +24,7 @@ int
 __dladdr (const void *address, Dl_info *info)
 {
 #ifdef SHARED
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dladdr (address, info);
 #endif
   return _dl_addr (address, info, NULL, NULL);
diff --git a/dlfcn/dladdr1.c b/dlfcn/dladdr1.c
index 5dadfd1..e0c9526 100644
--- a/dlfcn/dladdr1.c
+++ b/dlfcn/dladdr1.c
@@ -24,7 +24,7 @@ int
 __dladdr1 (const void *address, Dl_info *info, void **extra, int flags)
 {
 #ifdef SHARED
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dladdr1 (address, info, extra, flags);
 #endif
 
diff --git a/dlfcn/dlclose.c b/dlfcn/dlclose.c
index a9921c3..aab88c4 100644
--- a/dlfcn/dlclose.c
+++ b/dlfcn/dlclose.c
@@ -24,7 +24,7 @@ int
 __dlclose (void *handle)
 {
 #ifdef SHARED
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dlclose (handle);
 #endif
 
diff --git a/dlfcn/dlerror.c b/dlfcn/dlerror.c
index 3bf6049..b899d25 100644
--- a/dlfcn/dlerror.c
+++ b/dlfcn/dlerror.c
@@ -32,7 +32,7 @@ char *
 __dlerror (void)
 {
 # ifdef SHARED
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dlerror ();
 # endif
 
diff --git a/dlfcn/dlinfo.c b/dlfcn/dlinfo.c
index fc63c02..068db52 100644
--- a/dlfcn/dlinfo.c
+++ b/dlfcn/dlinfo.c
@@ -89,7 +89,7 @@ dlinfo_implementation (void *handle, int request, void *arg)
 int
 ___dlinfo (void *handle, int request, void *arg)
 {
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dlinfo (handle, request, arg);
   else
     return dlinfo_implementation (handle, request, arg);
diff --git a/dlfcn/dlmopen.c b/dlfcn/dlmopen.c
index 2437f5c..b41778f 100644
--- a/dlfcn/dlmopen.c
+++ b/dlfcn/dlmopen.c
@@ -80,7 +80,7 @@ dlmopen_implementation (Lmid_t nsid, const char *file, int mode,
 void *
 ___dlmopen (Lmid_t nsid, const char *file, int mode)
 {
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dlmopen (nsid, file, mode, RETURN_ADDRESS (0));
   else
     return dlmopen_implementation (nsid, file, mode, RETURN_ADDRESS (0));
diff --git a/dlfcn/dlopen.c b/dlfcn/dlopen.c
index 846ca38..2696dde 100644
--- a/dlfcn/dlopen.c
+++ b/dlfcn/dlopen.c
@@ -75,7 +75,7 @@ dlopen_implementation (const char *file, int mode, void *dl_caller)
 void *
 ___dlopen (const char *file, int mode)
 {
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dlopen (file, mode, RETURN_ADDRESS (0));
   else
     return dlopen_implementation (file, mode, RETURN_ADDRESS (0));
diff --git a/dlfcn/dlopenold.c b/dlfcn/dlopenold.c
index 6760143..5c21a00 100644
--- a/dlfcn/dlopenold.c
+++ b/dlfcn/dlopenold.c
@@ -70,7 +70,7 @@ __dlopen_nocheck (const char *file, int mode)
     mode |= RTLD_LAZY;
   args.mode = mode;
 
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dlopen (file, mode, RETURN_ADDRESS (0));
 
   return _dlerror_run (dlopen_doit, &args) ? NULL : args.new;
diff --git a/dlfcn/dlsym.c b/dlfcn/dlsym.c
index a71f8ae..2e9ff98 100644
--- a/dlfcn/dlsym.c
+++ b/dlfcn/dlsym.c
@@ -62,7 +62,7 @@ dlsym_implementation (void *handle, const char *name, void *dl_caller)
 void *
 ___dlsym (void *handle, const char *name)
 {
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dlsym (handle, name, RETURN_ADDRESS (0));
   else
     return dlsym_implementation (handle, name, RETURN_ADDRESS (0));
diff --git a/dlfcn/dlvsym.c b/dlfcn/dlvsym.c
index 72219d6..caa46ba 100644
--- a/dlfcn/dlvsym.c
+++ b/dlfcn/dlvsym.c
@@ -65,7 +65,7 @@ dlvsym_implementation (void *handle, const char *name, const char *version,
 void *
 ___dlvsym (void *handle, const char *name, const char *version)
 {
-  if (!rtld_active ())
+  if (GLRO (dl_dlfcn_hook) != NULL)
     return GLRO (dl_dlfcn_hook)->dlvsym (handle, name, version,
 					 RETURN_ADDRESS (0));
   else