llext: fix memory leak in no-data case

If there is no .data section in a llext module, the base data address is
replaced with .bss address while loading the module. There is no
corresponding logic during module unloading. This causes memory leak
because FW attempts to free memory under NULL address while the .bss
memory remains allocated. This change adds the missing logic.

Signed-off-by: Wojciech Jablonski <wojciech.jablonski@intel.com>

Author: wjablon1

src/library_manager/llext_manager.c

@@ -320,6 +320,8 @@ static int llext_manager_unload_module(struct lib_manager_module *mctx)
 	/* Writable data (.data, .bss, etc.) */
 	void __sparse_cache *va_base_data = (void __sparse_cache *)
 		mctx->segment[LIB_MANAGER_DATA].addr;
+	void __sparse_cache *va_bss_data = (void __sparse_cache *)
+		mctx->segment[LIB_MANAGER_BSS].addr;
 	size_t data_size = mctx->segment[LIB_MANAGER_DATA].size +
 		mctx->segment[LIB_MANAGER_BSS].size;
 	int err = 0, ret;
@@ -330,6 +332,8 @@ static int llext_manager_unload_module(struct lib_manager_module *mctx)
 	if (ret < 0)
 		err = ret;
 
+	va_base_data = va_base_data ? va_base_data : va_bss_data;
+
 	llext_manager_unmap_detached_sections(ldr, ext, LLEXT_MEM_DATA,
 					      va_base_data, data_size);
 	ret = llext_manager_align_unmap(va_base_data, data_size);