runtime_loader: support linking TLS symbols from any DSO

Previously TLS_DTPMOD relocation blindly returned ID of the current DSO.
This patch does proper symbol lookup if there is a symbol assigned to the
relocation and uses ID of the DSO in which the symbol is defined.

src/system/runtime_loader/arch/x86/arch_relocate.cpp

@@ -31,29 +31,22 @@ relocate_rel(image_t *rootImage, image_t *image, struct Elf32_Rel *rel,
 
 	for (i = 0; i * (int)sizeof(struct Elf32_Rel) < rel_len; i++) {
 		unsigned type = ELF32_R_TYPE(rel[i].r_info);
+		unsigned symbolIndex = ELF32_R_SYM(rel[i].r_info);
 
-		switch (type) {
-			case R_386_32:
-			case R_386_PC32:
-			case R_386_GLOB_DAT:
-			case R_386_JMP_SLOT:
-			case R_386_GOTOFF:
-			case R_386_TLS_DTPOFF32:
-			{
-				struct Elf32_Sym *sym;
-				status_t status;
-				sym = SYMBOL(image, ELF32_R_SYM(rel[i].r_info));
-
-				status = resolve_symbol(rootImage, image, sym, cache, &S);
-				if (status < B_OK) {
-					TRACE(("resolve symbol \"%s\" returned: %ld\n",
-						SYMNAME(image, sym), status));
-					printf("resolve symbol \"%s\" returned: %ld\n",
-						SYMNAME(image, sym), status);
-					return status;
-				}
+		image_t* symbolImage = NULL;
+		if (symbolIndex != 0) {
+			Elf32_Sym* sym = SYMBOL(image, symbolIndex);
+			status_t status = resolve_symbol(rootImage, image, sym, cache, &S,
+					&symbolImage);
+			if (status < B_OK) {
+				TRACE(("resolve symbol \"%s\" returned: %ld\n",
+					SYMNAME(image, sym), status));
+				printf("resolve symbol \"%s\" returned: %ld\n",
+					SYMNAME(image, sym), status);
+				return status;
 			}
 		}
+
 		switch (type) {
 			case R_386_NONE:
 				continue;
@@ -92,7 +85,8 @@ relocate_rel(image_t *rootImage, image_t *image, struct Elf32_Rel *rel,
 				break;
 #endif
 			case R_386_TLS_DTPMOD32:
-				final_val = image->dso_tls_id;
+				final_val = symbolImage == NULL
+							? image->dso_tls_id : symbolImage->dso_tls_id;
 				break;
 			case R_386_TLS_DTPOFF32:
 				final_val = S;

src/system/runtime_loader/arch/x86_64/arch_relocate.cpp

@@ -21,13 +21,14 @@ relocate_rela(image_t* rootImage, image_t* image, Elf64_Rela* rel,
 		int type = ELF64_R_TYPE(rel[i].r_info);
 		int symIndex = ELF64_R_SYM(rel[i].r_info);
 		Elf64_Addr symAddr = 0;
+		image_t* symbolImage = NULL;
 
 		// Resolve the symbol, if any.
 		if (symIndex != 0) {
 			Elf64_Sym* sym = SYMBOL(image, symIndex);
 
 			status_t status = resolve_symbol(rootImage, image, sym, cache,
-				&symAddr);
+				&symAddr, &symbolImage);
 			if (status != B_OK) {
 				TRACE(("resolve symbol \"%s\" returned: %" B_PRId32 "\n",
 					SYMNAME(image, sym), status));
@@ -57,7 +58,8 @@ relocate_rela(image_t* rootImage, image_t* image, Elf64_Rela* rel,
 				relocValue = image->regions[0].delta + rel[i].r_addend;
 				break;
 			case R_X86_64_DTPMOD64:
-				relocValue = image->dso_tls_id;
+				relocValue = symbolImage == NULL
+							? image->dso_tls_id : symbolImage->dso_tls_id;
 				break;
 			case R_X86_64_DTPOFF32:
 			case R_X86_64_DTPOFF64:

src/system/runtime_loader/elf_symbol_lookup.cpp

@@ -474,7 +474,7 @@ find_undefined_symbol_add_on(image_t* rootImage, image_t* image,
 
 int
 resolve_symbol(image_t* rootImage, image_t* image, elf_sym* sym,
-	SymbolLookupCache* cache, addr_t* symAddress)
+	SymbolLookupCache* cache, addr_t* symAddress, image_t** symbolImage)
 {
 	uint32 index = sym - image->syms;
 
@@ -581,6 +581,8 @@ resolve_symbol(image_t* rootImage, image_t* image, elf_sym* sym,
 
 	cache->SetSymbolValueAt(index, (addr_t)location);
 
+	if (symbolImage)
+		*symbolImage = sharedImage;
 	*symAddress = (addr_t)location;
 	return B_OK;
 }

src/system/runtime_loader/runtime_loader_private.h

@@ -76,7 +76,7 @@ status_t get_library_symbol(void* handle, void* caller, const char* symbolName,
 status_t get_next_image_dependency(image_id id, uint32* cookie,
 	const char** _name);
 int resolve_symbol(image_t* rootImage, image_t* image, elf_sym* sym,
-	SymbolLookupCache* cache, addr_t* sym_addr);
+	SymbolLookupCache* cache, addr_t* sym_addr, image_t** symbolImage = NULL);
 
 
 status_t elf_verify_header(void* header, size_t length);