Slightly improved fdlfcn functionality (still no clue on freeing those structs)

Author: GAMINGNOOBdev

source/boot/libFrostedWM.so

@@ -3,7 +3,10 @@
 
 #include <elf.h>
 
-typedef struct
+// signifies that (for example dlysm) should look through the list of loaded so files and find the address of the given symbol
+#define FLD_NEXT (void*)-1
+
+typedef struct fdlfcn_handle
 {
     void* address;
     Elf64_Ehdr ehdr;
@@ -24,6 +27,9 @@ typedef struct
     Elf64_Shdr* data_section_header;
     Elf64_Shdr* rodata_section_header;
     Elf64_Shdr* symtab_str_section_header;
+
+    struct fdlfcn_handle* prev;
+    struct fdlfcn_handle* next;
 } fdlfcn_handle;
 
 // immediately load sections into memory
@@ -33,4 +39,9 @@ fdlfcn_handle* fdlopen(void* filedata, int flags);
 void* fdlsym(fdlfcn_handle* handle, const char* symbol_name);
 int fdlclose(fdlfcn_handle* handle);
 
+// defines that make my life easier
+#define dlopen fdlopen
+#define dlsym fdlsym
+#define dlclose fdlclose
+
 #endif

source/includes/fdlfcn.h

@@ -6,7 +6,9 @@
 #include <heap.h>
 #include <elf.h>
 
-#define READ_FROM_MEMORY(dest, base, offset, size) printf("reading at address 0x%x", (uint64_t)base + (uint64_t)offset); memcpy(dest, (void*)( (uint64_t)base + (uint64_t)offset ), size)
+fdlfcn_handle* global_library_handles;
+
+#define READ_FROM_MEMORY(dest, base, offset, size) memcpy(dest, (void*)( (uint64_t)base + (uint64_t)offset ), size)
 
 void* fdl_load_section(void* filedata, Elf64_Shdr* section_header)
 {
@@ -69,6 +71,17 @@ void* fdlsym(fdlfcn_handle* handle, const char* symbol_name)
 {
     if (handle == NULL)
         return NULL;
+    if (handle == FLD_NEXT)
+    {
+        for (fdlfcn_handle* entry = global_library_handles; entry != NULL; entry = entry->next)
+        {
+            void* addr = fdlsym(entry, symbol_name);
+            if (addr != NULL)
+                return addr;
+        }
+        printf("Error: No library loaded with symbol '%s'", symbol_name);
+        return NULL;
+    }
 
     Elf64_Sym* symbols = handle->symbols;
 
@@ -93,8 +106,7 @@ void* fdlsym(fdlfcn_handle* handle, const char* symbol_name)
     for (int j = 0; j < symtab_section.sh_size / sizeof(Elf64_Sym); j++)
     {
         Elf64_Sym symbol = symbols[j];
-        char* symbol_name_str = (char*)((uint64_t)handle->symtab_str_section_data + symbol.st_name); 
-        printf("Symbol name: '%s'", symbol_name_str);
+        char* symbol_name_str = (char*)((uint64_t)handle->symtab_str_section_data + symbol.st_name);
         if (strcmp(symbol_name_str, symbol_name) == 0 && ELF64_ST_BIND(symbol.st_info) != STB_LOCAL && symbol.st_shndx == handle->text_section_index)
         {
             uintptr_t symbol_address = (uintptr_t)handle->text_section_data + symbol.st_value - handle->text_section_header->sh_offset;
@@ -112,6 +124,23 @@ int fdlclose(fdlfcn_handle* handle)
     if (handle == NULL)
         return 1;
 
+    for (fdlfcn_handle* entry = global_library_handles; entry != NULL; entry = entry->next)
+    {
+        if (entry != handle)
+            continue;
+
+        if (entry->prev != NULL)
+            entry->prev->next = entry->next;
+
+        if (entry->next != NULL)
+            entry->next->prev = entry->prev;
+
+        if (entry == global_library_handles)
+            global_library_handles = NULL;
+
+        break;
+    }
+
     return 0; /// TODO: somehow all the free calls cause a gp fault, fix that
 
     if (handle->text_section_data != NULL)
@@ -274,6 +303,8 @@ fdlfcn_handle* fdlopen(void* filedata, int flags)
     handle->ehdr = elf_header;
     handle->shdrs = section_headers;
     handle->symtab_index = symtab_index;
+    handle->next = NULL;
+    handle->prev = NULL;
 
     if (fdl_apply_relocations(handle, reloc_section_index) != 0 && reloc_section_index != -1)
     {
@@ -297,6 +328,17 @@ fdlfcn_handle* fdlopen(void* filedata, int flags)
         return NULL;
     }
 
+    if (global_library_handles == NULL)
+    {
+        global_library_handles = handle;
+    }
+    else
+    {
+        global_library_handles->prev = handle;
+        handle->next = global_library_handles;
+        global_library_handles = handle;
+    }
+
     info("fdlopen: Successfully loaded .so file", __FILE__);
 
     return handle;

source/kernel/C/fdlfcn.c

@@ -99,10 +99,9 @@ extern int64* wm_addr;
 
 void start_window_manager(){
     void* file_addr = wm_addr;
-    elf_load_from_memory(file_addr);
     fdlfcn_handle* handle = fdlopen(file_addr, FDL_IMMEDIATE);
     int(*startfunction)(void);
-    startfunction = (int(*)(void))fdlsym(handle, "_start");
+    startfunction = (int(*)(void))fdlsym(FLD_NEXT, "_start");
     if (startfunction != NULL)
     {
         int result = startfunction();