File aarch64-elf-machine-load-address.patch of Package glibc.29706

2017-10-18  Renlin Li  <renlin.li@arm.com>

	* sysdeps/aarch64/dl-machine.h (elf_machine_load_address): Use
	_DYNAMIC symbol to calculate load address.

Index: glibc-2.22/sysdeps/aarch64/dl-machine.h
===================================================================
--- glibc-2.22.orig/sysdeps/aarch64/dl-machine.h
+++ glibc-2.22/sysdeps/aarch64/dl-machine.h
@@ -49,26 +49,11 @@ elf_machine_load_address (void)
   /* To figure out the load address we use the definition that for any symbol:
      dynamic_addr(symbol) = static_addr(symbol) + load_addr
 
-     The choice of symbol is arbitrary. The static address we obtain
-     by constructing a non GOT reference to the symbol, the dynamic
-     address of the symbol we compute using adrp/add to compute the
-     symbol's address relative to the PC.
-     This depends on 32bit relocations being resolved at link time
-     and that the static address fits in the 32bits.  */
+    _DYNAMIC sysmbol is used here as its link-time address stored in
+    the special unrelocated first GOT entry.  */
 
-  ElfW(Addr) static_addr;
-  ElfW(Addr) dynamic_addr;
-
-  asm ("					\n"
-"	adrp	%1, _dl_start;			\n"
-"	add	%1, %1, #:lo12:_dl_start	\n"
-"	ldr	%w0, 1f				\n"
-"	b	2f				\n"
-"1:						\n"
-"	.word	_dl_start			\n"
-"2:						\n"
-    : "=r" (static_addr),  "=r" (dynamic_addr));
-  return dynamic_addr - static_addr;
+    extern ElfW(Dyn) _DYNAMIC[] attribute_hidden;
+    return (ElfW(Addr)) &_DYNAMIC - elf_machine_dynamic ();
 }
 
 /* Set up the loaded object described by L so its unrelocated PLT