ld: load dynamic linker at static address on Linux

* move stack area to static address at beginning of binary
* set ELF type of linker from shared to executable

fixes #3479

repos/base-linux/src/ld/stack_area.ld

@@ -1,5 +1,5 @@
 /*
- * \brief  Linux-specific linker script additions (STDLIB = no)
+ * \brief  Linux-specific linker script additions
  * \author Christian Helmuth
  * \date   2010-09-22
  */
@@ -19,17 +19,13 @@ PHDRS
 SECTIONS
 {
 	/*
-	 * The virtual gap between start of text segment (0x0) and stack area
+	 * Start of Linux binary and stack area
-	 * must be sufficiently large to hold either the entire dynamic linker (text +
-	 * data) or core (0x1000000 + text + data). Note, core-linux includes 80 MiB
-	 * core-local memory in the BSS.
 	 */
-	. = 0x8000000; /* 128 MiB */
+	. = 0x40000000; /* 1GB */
 	_stack_area_start = .;
 
 	/*
-	 * Since Linux loads ldso page-aligned, we align the stack area after
+	 * 256 MB
-	 * loading to a 1 MiB boundary, therefore we reserve one MiB more here.
 	 */
-	.stack_area : { . += 0x10100000; } : stack_area
+	.stack_area : { . += 0x10000000; } : stack_area
 }

repos/base/lib/mk/ld-platform.inc

@@ -30,13 +30,22 @@ symbol.map: $(BASE_DIR)/lib/symbols/ld
 ifneq ($(filter linux, $(SPECS)),)
 
 ENTRY_POINT = _start_initial_stack
-LD_SCRIPT_SO = $(BASE_DIR)/src/ld/genode_rel.ld \
+LD_SCRIPT_SO = $(call select_from_repositories,src/ld/stack_area.ld) \
-              -T$(call select_from_repositories,src/ld/stack_area.ld) \
+               -T$(BASE_DIR)/src/ld/genode_rel.ld
 
 ifneq ($(filter x86_32, $(SPECS)),)
 LD_OPT     += -T$(DIR)/linux-32.ld
 endif
 
+#
+# set dynamic linker ELF type to executable
+#
+ifeq ($(called_from_lib_mk),yes)
+$(LIB).lib.so.stripped: postprocess.tag
+postprocess.tag: $(LIB).lib.so
+	$(VERBOSE)printf "\x02" | dd of=$(LIB).lib.so bs=1 seek=16 count=1 conv=notrunc
+endif
+
 else
 ENTRY_POINT = _start
 LD_OPT     += -T$(DIR)/linker.ld