Implement _dl_catch_error, _dl_signal_error in libc.so [BZ #16628]

This change moves the main implementation of _dl_catch_error,
_dl_signal_error to libc.so, where TLS variables can be used
directly.  This removes a writable function pointer from the
rtld_global variable.

For use during initial relocation, minimal implementations of these
functions are provided in ld.so.  These are eventually interposed
by the libc.so implementations.  This is implemented by compiling
elf/dl-error-skeleton.c twice, via elf/dl-error.c and
elf/dl-error-minimal.c.

As a side effect of this change, the static version of dl-error.c
no longer includes support for the
_dl_signal_cerror/_dl_receive_error mechanism because it is only
used in ld.so.

1 files changed, 0 insertions, 4 deletions

diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c
index 48fab50c4e..0fd54a0a93 100644
--- a/nptl/nptl-init.c
+++ b/nptl/nptl-init.c
@@ -456,10 +456,6 @@ __pthread_initialize_minimal_internal (void)
   lll_unlock (__default_pthread_attr_lock, LLL_PRIVATE);
 
 #ifdef SHARED
-  /* Transfer the old value from the dynamic linker's internal location.  */
-  *__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) ();
-  GL(dl_error_catch_tsd) = &__libc_dl_error_tsd;
-
   /* Make __rtld_lock_{,un}lock_recursive use pthread_mutex_{,un}lock,
      keep the lock count from the ld.so implementation.  */
   GL(dl_rtld_lock_recursive) = (void *) __pthread_mutex_lock;