Refactor dynamic linker API, fix system/dynlink example

2 files changed, 27 insertions, 32 deletions

diff --git a/libpsn00b/psxetc/_dl_resolve_wrapper.s b/libpsn00b/psxetc/_dl_resolve_wrapper.s
index 069ee84..7f1132b 100644
--- a/libpsn00b/psxetc/_dl_resolve_wrapper.s
+++ b/libpsn00b/psxetc/_dl_resolve_wrapper.s
@@ -4,7 +4,7 @@
 # This function is called by the lazy loader stubs generated by GCC in the
 # .plt/.MIPS.stubs section when attempting to call a GOT entry whose address
 # hasn't yet been resolved. The generated stubs conform to the MIPS ABI and
-# uses the following registers to pass the following parameters:
+# uses the following registers:
 # - $t7 = address the resolved function should return to (i.e. $ra of the
 #   caller that triggered the stub)
 # - $t8 = index of the function in the .dynsym symbol table
@@ -25,13 +25,13 @@ _dl_resolve_wrapper:
 
 	# Figure out where the DLL's struct is. dlinit() places a pointer to the
 	# struct in the second GOT entry, so it's just a matter of indexing the GOT
-	# using GP. Then call _dl_resolve_helper with the struct and $t8 as
+	# using $gp. Then call _dl_resolve_helper with the struct and $t8 as
 	# arguments, and store the return value into $t0.
-	lw    $a0, -0x7fec($gp) # sizeof(uint32_t) - 0x7ff0 (see dll.ld)
+	lw    $a0, -0x7fec($gp) # (DLL *) sizeof(uint32_t) - 0x7ff0 [see dll.ld]
 	move  $a1, $t8
 
 	jal   _dl_resolve_helper
-	addiu $sp, -8 # (branch delay)
+	addiu $sp, -8
 	addiu $sp, 8
 
 	move  $t0, $v0
diff --git a/libpsn00b/psxetc/dl.c b/libpsn00b/psxetc/dl.c
index e43374f..cbdcb66 100644
--- a/libpsn00b/psxetc/dl.c
+++ b/libpsn00b/psxetc/dl.c
@@ -38,8 +38,9 @@
 //#define DEBUG
 
 // Comment before building to disable functions that rely on BIOS file APIs,
-// i.e. DL_LoadSymbolMap() and dlopen().
-#define USE_FILE_API
+// i.e. DL_LoadSymbolMapFromFile() and DL_LoadDLLFromFile().
+// FIXME: those seem to be broken currently, and shouldn't be used anyway
+//#define USE_FILE_API
 
 /* Private types */
 
@@ -132,7 +133,7 @@ static uint32_t _elf_hash(const char *str) {
 }
 
 #ifdef USE_FILE_API
-static uint8_t *_load_file(const char *filename, size_t *size_output) {
+static uint8_t *_dl_load_file(const char *filename, size_t *size_output) {
 	int32_t fd = open(filename, 1);
 	if (fd < 0) {
 		_LOG("psxetc: Can't open %s, error = %d\n", filename, fd);
@@ -286,10 +287,10 @@ int32_t DL_ParseSymbolMap(const char *ptr, size_t size) {
 	return entries;
 }
 
-int32_t DL_LoadSymbolMap(const char *filename) {
 #ifdef USE_FILE_API
+int32_t DL_LoadSymbolMapFromFile(const char *filename) {
 	size_t size;
-	char   *ptr = _load_file(filename, &size);
+	char   *ptr = _dl_load_file(filename, &size);
 	if (!ptr)
 		return -1;
 
@@ -297,10 +298,8 @@ int32_t DL_LoadSymbolMap(const char *filename) {
 	free(ptr);
 
 	return entries;
-#else
-	_ERROR(RTLD_E_NO_FILE_API, -1);
-#endif
 }
+#endif
 
 void DL_UnloadSymbolMap(void) {
 	if (!_symbol_map.entries)
@@ -354,7 +353,7 @@ void DL_SetResolveCallback(void *(*callback)(DLL *, const char *)) {
 
 /* Library loading and linking API */
 
-DLL *dlinit(void *ptr, size_t size, DL_ResolveMode mode) {
+DLL *DL_CreateDLL(void *ptr, size_t size, DL_ResolveMode mode) {
 	if (!ptr)
 		_ERROR(RTLD_E_DLL_NULL, 0);
 
@@ -365,7 +364,7 @@ DLL *dlinit(void *ptr, size_t size, DL_ResolveMode mode) {
 	}
 
 	dll->ptr        = ptr;
-	dll->malloc_ptr = 0;
+	dll->malloc_ptr = (mode & RTLD_FREE_ON_DESTROY) ? ptr : 0;
 	dll->size       = size;
 	_LOG("psxetc: Initializing DLL at %08x\n", ptr);
 
@@ -548,7 +547,7 @@ DLL *dlinit(void *ptr, size_t size, DL_ResolveMode mode) {
 
 		// If RTLD_NOW was passed, resolve GOT entries ahead of time by
 		// cross-referencing them with the symbol table.
-		if (mode != RTLD_NOW)
+		if (!(mode & RTLD_NOW))
 			continue;
 
 		for (uint32_t j = got_offset; j < dll->got_length; j++) {
@@ -584,7 +583,7 @@ DLL *dlinit(void *ptr, size_t size, DL_ResolveMode mode) {
 	// _start() for regular executables, but we have to do it outside of the
 	// DLL as there's no _start() or even a defined entry point within the
 	// DLL itself.
-	const uint32_t *ctor_list = dlsym(dll, "__CTOR_LIST__");
+	const uint32_t *ctor_list = DL_GetDLLSymbol(dll, "__CTOR_LIST__");
 	if (ctor_list) {
 		for (uint32_t i = ((uint32_t) ctor_list[0]); i >= 1; i--) {
 			void (*ctor)(void) = (void (*)(void)) ctor_list[i];
@@ -595,32 +594,28 @@ DLL *dlinit(void *ptr, size_t size, DL_ResolveMode mode) {
 	return dll;
 }
 
-DLL *dlopen(const char *filename, DL_ResolveMode mode) {
 #ifdef USE_FILE_API
+DLL *DL_LoadDLLFromFile(const char *filename, DL_ResolveMode mode) {
 	size_t size;
-	char   *ptr = _load_file(filename, &size);
+	char   *ptr = _dl_load_file(filename, &size);
 	if (!ptr)
 		return 0;
 
-	DLL *dll = dlinit(ptr, size, mode);
-	if (dll)
-		dll->malloc_ptr = dll->ptr;
-	else
+	DLL *dll = DL_CreateDLL(ptr, size, mode | RTLD_FREE_ON_DESTROY);
+	if (!dll)
 		free(ptr);
 
 	return dll;
-#else
-	_ERROR(RTLD_E_NO_FILE_API, 0);
-#endif
 }
+#endif
 
-void dlclose(DLL *dll) {
+void DL_DestroyDLL(DLL *dll) {
 	if (dll == RTLD_DEFAULT)
 		return;
 
 	if (dll->ptr) {
 		// Call the DLL's global destructors.
-		const uint32_t *dtor_list = dlsym(dll, "__DTOR_LIST__");
+		const uint32_t *dtor_list = DL_GetDLLSymbol(dll, "__DTOR_LIST__");
 		if (dtor_list) {
 			for (uint32_t i = 0; i < ((uint32_t) dtor_list[0]); i++) {
 				void (*dtor)(void) = (void (*)(void)) dtor_list[i + 1];
@@ -629,15 +624,15 @@ void dlclose(DLL *dll) {
 		}
 	}
 
-	// If the DLL is associated to a buffer allocated by dlopen(), free that
-	// buffer.
+	// If the DLL is associated to a buffer allocated by DL_LoadDLLFromFile(),
+	// free that buffer.
 	if (dll->malloc_ptr)
 		free(dll->malloc_ptr);
 
 	free(dll);
 }
 
-void *dlsym(DLL *dll, const char *name) {
+void *DL_GetDLLSymbol(const DLL *dll, const char *name) {
 	if (dll == RTLD_DEFAULT)
 		return DL_GetSymbolByName(name);
 		//return _dl_resolve_callback(RTLD_DEFAULT, name);
@@ -654,7 +649,7 @@ void *dlsym(DLL *dll, const char *name) {
 	// provided.
 	for (uint32_t i = bucket[hash_mod]; i != 0xffffffff;) {
 		if (i >= nchain) {
-			_LOG("psxetc: dlsym() index out of bounds (i = %d, n = %d)\n", i, nchain);
+			_LOG("psxetc: DL_GetDLLSymbol() index out of bounds (i = %d, n = %d)\n", i, nchain);
 			_ERROR(RTLD_E_HASH_LOOKUP, 0);
 		}
 
@@ -673,7 +668,7 @@ void *dlsym(DLL *dll, const char *name) {
 	_ERROR(RTLD_E_DLL_SYMBOL, 0);
 }
 
-DL_Error dlerror(void) {
+DL_Error DL_GetLastError(void) {
 	DL_Error last = _error_code;
 	_error_code   = RTLD_E_NONE;