runtime_loader: randomize position of runtime_loader

* make runtime_loader a dynammically linked object
 * add kernel support for loading user images that need to be relocated
 * load runtime_loader at random address

src/system/kernel/elf.cpp

@@ -1069,7 +1069,7 @@ elf_resolve_symbol(struct elf_image_info *image, elf_sym *symbol,
 
 /*! Until we have shared library support, just this links against the kernel */
 static int
-elf_relocate(struct elf_image_info *image)
+elf_relocate(struct elf_image_info* image, struct elf_image_info* resolveImage)
 {
 	int status = B_NO_ERROR;
 
@@ -1079,7 +1079,7 @@ elf_relocate(struct elf_image_info *image)
 	if (image->rel) {
 		TRACE(("total %i rel relocs\n", image->rel_len / (int)sizeof(elf_rel)));
 
-		status = arch_elf_relocate_rel(image, sKernelImage, image->rel,
+		status = arch_elf_relocate_rel(image, resolveImage, image->rel,
 			image->rel_len);
 		if (status < B_OK)
 			return status;
@@ -1089,12 +1089,12 @@ elf_relocate(struct elf_image_info *image)
 		if (image->pltrel_type == DT_REL) {
 			TRACE(("total %i plt-relocs\n",
 				image->pltrel_len / (int)sizeof(elf_rel)));
-			status = arch_elf_relocate_rel(image, sKernelImage, image->pltrel,
+			status = arch_elf_relocate_rel(image, resolveImage, image->pltrel,
 				image->pltrel_len);
 		} else {
 			TRACE(("total %i plt-relocs\n",
 				image->pltrel_len / (int)sizeof(elf_rela)));
-			status = arch_elf_relocate_rela(image, sKernelImage,
+			status = arch_elf_relocate_rela(image, resolveImage,
 				(elf_rela *)image->pltrel, image->pltrel_len);
 		}
 		if (status < B_OK)
@@ -1105,7 +1105,7 @@ elf_relocate(struct elf_image_info *image)
 		TRACE(("total %i rel relocs\n",
 			image->rela_len / (int)sizeof(elf_rela)));
 
-		status = arch_elf_relocate_rela(image, sKernelImage, image->rela,
+		status = arch_elf_relocate_rela(image, resolveImage, image->rela,
 			image->rela_len);
 		if (status < B_OK)
 			return status;
@@ -1288,7 +1288,7 @@ insert_preloaded_image(preloaded_elf_image *preloadedImage, bool kernel)
 		if (status != B_OK)
 			goto error1;
 
-		status = elf_relocate(image);
+		status = elf_relocate(image, sKernelImage);
 		if (status != B_OK)
 			goto error1;
 	} else
@@ -1825,6 +1825,8 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 	ssize_t length;
 	int fd;
 	int i;
+	addr_t delta = 0;
+	uint32 addressSpec = B_RANDOMIZED_BASE_ADDRESS;
 
 	TRACE(("elf_load: entry path '%s', team %p\n", path, team));
 
@@ -1854,6 +1856,14 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 	if (status < B_OK)
 		goto error;
 
+	struct elf_image_info* image;
+	image = create_image_struct();
+	if (image == NULL) {
+		status = B_NO_MEMORY;
+		goto error;
+	}
+	image->elf_header = &elfHeader;
+
 	// read program header
 
 	programHeaders = (elf_phdr *)malloc(
@@ -1861,7 +1871,7 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 	if (programHeaders == NULL) {
 		dprintf("error allocating space for program headers\n");
 		status = B_NO_MEMORY;
-		goto error;
+		goto error2;
 	}
 
 	TRACE(("reading in program headers at 0x%lx, length 0x%x\n",
@@ -1871,12 +1881,12 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 	if (length < B_OK) {
 		status = length;
 		dprintf("error reading in program headers\n");
-		goto error;
+		goto error2;
 	}
 	if (length != elfHeader.e_phnum * elfHeader.e_phentsize) {
 		dprintf("short read while reading in program headers\n");
 		status = -1;
-		goto error;
+		goto error2;
 	}
 
 	// construct a nice name for the region we have to create below
@@ -1904,13 +1914,21 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 	for (i = 0; i < elfHeader.e_phnum; i++) {
 		char regionName[B_OS_NAME_LENGTH];
 		char *regionAddress;
+		char *originalRegionAddress;
 		area_id id;
 
+		if (programHeaders[i].p_type == PT_DYNAMIC) {
+			image->dynamic_section = programHeaders[i].p_vaddr;
+			continue;
+		}
+
 		if (programHeaders[i].p_type != PT_LOAD)
 			continue;
 
-		regionAddress = (char *)ROUNDDOWN(programHeaders[i].p_vaddr,
+		regionAddress = (char *)(ROUNDDOWN(programHeaders[i].p_vaddr,
-			B_PAGE_SIZE);
+			B_PAGE_SIZE) + delta);
+		originalRegionAddress = regionAddress;
+
 		if (programHeaders[i].p_flags & PF_WRITE) {
 			// rw/data segment
 			size_t memUpperBound = (programHeaders[i].p_vaddr % B_PAGE_SIZE)
@@ -1924,18 +1942,21 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 			sprintf(regionName, "%s_seg%drw", baseName, i);
 
 			id = vm_map_file(team->id, regionName, (void **)&regionAddress,
-				B_EXACT_ADDRESS, fileUpperBound,
+				addressSpec, fileUpperBound,
 				B_READ_AREA | B_WRITE_AREA, REGION_PRIVATE_MAP, false,
 				fd, ROUNDDOWN(programHeaders[i].p_offset, B_PAGE_SIZE));
 			if (id < B_OK) {
 				dprintf("error mapping file data: %s!\n", strerror(id));
 				status = B_NOT_AN_EXECUTABLE;
-				goto error;
+				goto error2;
 			}
 
 			imageInfo.data = regionAddress;
 			imageInfo.data_size = memUpperBound;
 
+			image->data_region.start = (addr_t)regionAddress;
+			image->data_region.size = memUpperBound;
+
 			// clean garbage brought by mmap (the region behind the file,
 			// at least parts of it are the bss and have to be zeroed)
 			addr_t start = (addr_t)regionAddress
@@ -1965,7 +1986,7 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 				if (id < B_OK) {
 					dprintf("error allocating bss area: %s!\n", strerror(id));
 					status = B_NOT_AN_EXECUTABLE;
-					goto error;
+					goto error2;
 				}
 			}
 		} else {
@@ -1976,20 +1997,42 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 				+ (programHeaders[i].p_vaddr % B_PAGE_SIZE), B_PAGE_SIZE);
 
 			id = vm_map_file(team->id, regionName, (void **)&regionAddress,
-				B_EXACT_ADDRESS, segmentSize,
+				addressSpec, segmentSize,
-				B_READ_AREA | B_EXECUTE_AREA, REGION_PRIVATE_MAP, false,
+				B_READ_AREA | B_EXECUTE_AREA | B_WRITE_AREA, REGION_PRIVATE_MAP,
-				fd, ROUNDDOWN(programHeaders[i].p_offset, B_PAGE_SIZE));
+				false, fd, ROUNDDOWN(programHeaders[i].p_offset, B_PAGE_SIZE));
 			if (id < B_OK) {
 				dprintf("error mapping file text: %s!\n", strerror(id));
 				status = B_NOT_AN_EXECUTABLE;
-				goto error;
+				goto error2;
 			}
 
 			imageInfo.text = regionAddress;
 			imageInfo.text_size = segmentSize;
+
+			image->text_region.start = (addr_t)regionAddress;
+			image->text_region.size = segmentSize;
+		}
+
+		if (addressSpec != B_EXACT_ADDRESS) {
+			addressSpec = B_EXACT_ADDRESS;
+			delta = regionAddress - originalRegionAddress;
 		}
 	}
 
+	image->data_region.delta = delta;
+	image->text_region.delta = delta;
+
+	// modify the dynamic ptr by the delta of the regions
+	image->dynamic_section += image->text_region.delta;
+
+	status = elf_parse_dynamic_section(image);
+	if (status != B_OK)
+		goto error2;
+
+	status = elf_relocate(image, image);
+	if (status != B_OK)
+		goto error2;
+
 	// register the loaded image
 	imageInfo.type = B_LIBRARY_IMAGE;
     imageInfo.device = st.st_dev;
@@ -2009,9 +2052,13 @@ elf_load_user_image(const char *path, Team *team, int flags, addr_t *entry)
 
 	TRACE(("elf_load: done!\n"));
 
-	*entry = elfHeader.e_entry;
+	*entry = elfHeader.e_entry + delta;
 	status = B_OK;
 
+error2:
+	image->elf_header = NULL;
+	delete_elf_image(image);
+
 error:
 	free(programHeaders);
 	_kern_close(fd);
@@ -2258,7 +2305,7 @@ load_kernel_add_on(const char *path)
 	if (status != B_OK)
 		goto error5;
 
-	status = elf_relocate(image);
+	status = elf_relocate(image, sKernelImage);
 	if (status < B_OK)
 		goto error5;
 

src/system/ldscripts/x86/runtime_loader.ld

@@ -5,7 +5,7 @@ ENTRY(runtime_loader)
 SEARCH_DIR("libgcc");
 SECTIONS
 {
-	. = 0x00100000 + SIZEOF_HEADERS;
+	. = 0x00000000 + SIZEOF_HEADERS;
 
 	.interp : { *(.interp) }
 	.hash : { *(.hash) }

src/system/ldscripts/x86_64/runtime_loader.ld

@@ -5,7 +5,7 @@ ENTRY(runtime_loader)
 SEARCH_DIR("libgcc");
 SECTIONS
 {
-	. = 0x00200000 + SIZEOF_HEADERS;
+	. = 0x00000000 + SIZEOF_HEADERS;
 
 	.interp : { *(.interp) }
 	.hash : { *(.hash) }

src/system/runtime_loader/Jamfile

@@ -91,7 +91,7 @@ Ld runtime_loader :
 	$(TARGET_STATIC_LIBSUPC++)
 	$(TARGET_GCC_LIBGCC)
 	: $(HAIKU_TOP)/src/system/ldscripts/$(TARGET_ARCH)/runtime_loader.ld
-	: --no-undefined
+	: --no-undefined -shared -soname=runtime_loader
 ;
 
 HaikuSubInclude arch $(TARGET_ARCH) ;