Implement <unwind-link.h> for dynamically loading the libgcc_s unwinder

This will be used to consolidate the libgcc_s access for backtrace
and pthread_cancel.

Unlike the existing backtrace implementations, it provides some
hardening based on pointer mangling.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/sysdeps/mach/hurd/fork.c b/sysdeps/mach/hurd/fork.c
index fb6c7ee8b7..2b39f4e8b5 100644
--- a/sysdeps/mach/hurd/fork.c
+++ b/sysdeps/mach/hurd/fork.c
@@ -29,6 +29,7 @@
 #include <tls.h>
 #include <malloc/malloc-internal.h>
 #include <nss/nss_database.h>
+#include <unwind-link.h>
 
 #undef __fork
 
@@ -667,6 +668,8 @@ __fork (void)
       __sigemptyset (&_hurd_global_sigstate->pending);
       __sigemptyset (&ss->pending);
 
+      __libc_unwind_link_after_fork ();
+
       /* Release malloc locks.  */
       _hurd_malloc_fork_child ();
       call_function_static_weak (__malloc_fork_unlock_child);