From e340f717a422917491cebe4b693c6d30416ea0f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Duval?= <jerome.duval@gmail.com>
Date: Tue, 11 Oct 2016 22:26:06 +0200
Subject: [PATCH] runtime_loader: add support for ELF init/term routine arrays.

* binutils 2.27 defaults to DT_INIT_ARRAY instead of DT_INIT.
---
 .../private/runtime_loader/runtime_loader.h   |  6 ++++
 src/system/runtime_loader/elf.cpp             | 24 +++++++++++++++
 src/system/runtime_loader/elf_load_image.cpp  | 30 +++++++++++++++++--
 3 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/headers/private/runtime_loader/runtime_loader.h b/headers/private/runtime_loader/runtime_loader.h
index 6a754f2330..d93f676af2 100644
--- a/headers/private/runtime_loader/runtime_loader.h
+++ b/headers/private/runtime_loader/runtime_loader.h
@@ -115,6 +115,12 @@ typedef struct image_t {
 	int					rela_len;
 	elf_rel				*pltrel;
 	int					pltrel_len;
+	addr_t				*init_array;
+	int					init_array_len;
+	addr_t				*preinit_array;
+	int					preinit_array_len;
+	addr_t				*term_array;
+	int					term_array_len;
 
 	unsigned			dso_tls_id;
 
diff --git a/src/system/runtime_loader/elf.cpp b/src/system/runtime_loader/elf.cpp
index 6d30bbb7f2..03b8bd1c73 100644
--- a/src/system/runtime_loader/elf.cpp
+++ b/src/system/runtime_loader/elf.cpp
@@ -257,9 +257,21 @@ init_dependencies(image_t *image, bool initHead)
 
 		TRACE(("%ld:  init: %s\n", find_thread(NULL), image->name));
 
+		if (image->preinit_array) {
+			uint count_preinit = image->preinit_array_len / sizeof(addr_t);
+			for (uint j = 0; j < count_preinit; j++)
+				((init_term_function)image->preinit_array[j])(image->id);
+		}
+
 		if (image->init_routine != 0)
 			((init_term_function)image->init_routine)(image->id);
 
+		if (image->init_array) {
+			uint count_init = image->init_array_len / sizeof(addr_t);
+			for (uint j = 0; j < count_init; j++)
+				((init_term_function)image->init_array[j])(image->id);
+		}
+
 		image_event(image, IMAGE_EVENT_INITIALIZED);
 	}
 	TRACE(("%ld:  init done.\n", find_thread(NULL)));
@@ -633,6 +645,12 @@ unload_library(void* handle, image_id imageID, bool addOn)
 
 			image_event(image, IMAGE_EVENT_UNINITIALIZING);
 
+			if (image->term_array) {
+				uint count_term = image->term_array_len / sizeof(addr_t);
+				for (uint i = count_term; i-- > 0;)
+					((init_term_function)image->term_array[i])(image->id);
+			}
+
 			if (image->term_routine)
 				((init_term_function)image->term_routine)(image->id);
 
@@ -1017,6 +1035,12 @@ terminate_program(void)
 
 		image_event(image, IMAGE_EVENT_UNINITIALIZING);
 
+		if (image->term_array) {
+			uint count_term = image->term_array_len / sizeof(addr_t);
+			for (uint j = count_term; j-- > 0;)
+				((init_term_function)image->term_array[j])(image->id);
+		}
+
 		if (image->term_routine)
 			((init_term_function)image->term_routine)(image->id);
 
diff --git a/src/system/runtime_loader/elf_load_image.cpp b/src/system/runtime_loader/elf_load_image.cpp
index 73ffad1453..7181562c66 100644
--- a/src/system/runtime_loader/elf_load_image.cpp
+++ b/src/system/runtime_loader/elf_load_image.cpp
@@ -339,6 +339,33 @@ parse_dynamic_segment(image_t* image)
 				}
 				break;
 			}
+			case DT_INIT_ARRAY:
+				// array of pointers to initialization functions
+				image->init_array = (addr_t*)
+					(d[i].d_un.d_ptr + image->regions[0].delta);
+				break;
+			case DT_INIT_ARRAYSZ:
+				// size in bytes of the array of initialization functions
+				image->init_array_len = d[i].d_un.d_val;
+				break;
+			case DT_PREINIT_ARRAY:
+				// array of pointers to pre-initialization functions
+				image->preinit_array = (addr_t*)
+					(d[i].d_un.d_ptr + image->regions[0].delta);
+				break;
+			case DT_PREINIT_ARRAYSZ:
+				// size in bytes of the array of pre-initialization functions
+				image->preinit_array_len = d[i].d_un.d_val;
+				break;
+			case DT_FINI_ARRAY:
+				// array of pointers to termination functions
+				image->term_array = (addr_t*)
+					(d[i].d_un.d_ptr + image->regions[0].delta);
+				break;
+			case DT_FINI_ARRAYSZ:
+				// size in bytes of the array of termination functions
+				image->term_array_len = d[i].d_un.d_val;
+				break;
 			default:
 				continue;
 
@@ -348,9 +375,6 @@ parse_dynamic_segment(image_t* image)
 			// DT_SYMENT: The size of a symbol table entry.
 			// DT_PLTREL: The type of the PLT relocation entries (DT_JMPREL).
 			// DT_BIND_NOW/DF_BIND_NOW: No lazy binding allowed.
-			// DT_INIT_ARRAY[SZ], DT_FINI_ARRAY[SZ]: Initialization/termination
-			//		function arrays.
-			// DT_PREINIT_ARRAY[SZ]: Preinitialization function array.
 			// DT_RUNPATH: Library search path (supersedes DT_RPATH).
 			// DT_TEXTREL/DF_TEXTREL: Indicates whether text relocations are
 			//		required (for optimization purposes only).