elf: Add <dl-debug.h>

Add <dl-debug.h> to setup debugging entry in PT_DYNAMIC segment to support
DT_DEBUG, DT_MIPS_RLD_MAP_REL and DT_MIPS_RLD_MAP.

Tested on x86-64, x32 and i686 as well as with build-many-glibcs.py.

1 files changed, 41 insertions, 0 deletions

diff --git a/sysdeps/mips/dl-debug.h b/sysdeps/mips/dl-debug.h
new file mode 100644
index 0000000000..c41329a617
--- /dev/null
+++ b/sysdeps/mips/dl-debug.h
@@ -0,0 +1,41 @@
+/* Debugging support.  MIPS version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _DL_DEBUG_H
+#define _DL_DEBUG_H
+
+/* If there is a DT_MIPS_RLD_MAP_REL or DT_MIPS_RLD_MAP entry in the
+   dynamic section, fill in the debug map pointer with the run-time
+   address of the r_debug structure.  */
+
+static inline void
+__attribute ((always_inline))
+elf_setup_debug_entry (struct link_map *l, struct r_debug *r)
+{
+  if (l->l_info[DT_MIPS (RLD_MAP_REL)] != NULL)
+    {
+      char *ptr = (char *) l->l_info[DT_MIPS (RLD_MAP_REL)];
+      ptr += l->l_info[DT_MIPS (RLD_MAP_REL)]->d_un.d_val;
+      *(ElfW(Addr) *) ptr = (ElfW(Addr)) r;
+    }
+  else if (l->l_info[DT_MIPS (RLD_MAP)] != NULL)
+    *(ElfW(Addr) *) (l->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr)
+      = (ElfW(Addr)) r;
+}
+
+#endif /* _DL_DEBUG_H */