fix(libc): return the calling thread from _Thrd_id as the console's libc.prx does

core/libs/prx/libc/include/Api.hpp

@@ -1004,7 +1004,7 @@ void APS5_VABI _ZNSt4_Pad8_ReleaseEv_nid_postfix(GuestPad* pad);
 void APS5_VABI _ZNSt4_Pad7_LaunchEPP7pthread_nid_postfix(GuestPad* pad, void** thread);
 int APS5_VABI _Thrd_join_nid_postfix(void* thread, int* code);
 int APS5_VABI _Thrd_detach_nid_postfix(void* thread);
-int APS5_VABI _Thrd_id_nid_postfix(void);
+void* APS5_VABI _Thrd_id_nid_postfix(void);
 void APS5_VABI _Call_once_nid_postfix(std::int32_t* flag, void (APS5_VABI* function)(void));
 int APS5_VABI _Tss_create_nid_postfix(int* key, void (APS5_VABI* destructor)(void*));
 int APS5_VABI _Tss_delete_nid_postfix(int key);

core/libs/prx/libc/src/Threads.cpp

@@ -488,11 +488,6 @@ int APS5_VABI _Thrd_detach_nid_postfix(void* thread) {
     return detach(thread) == 0 ? threadSuccess : threadError;
 }
 
-int APS5_VABI _Thrd_id_nid_postfix(void) {
-    NotImplemented_nid_no_patch(__func__);
-    return 0;
-}
-
 [[noreturn]] void APS5_VABI _ZSt16_Throw_Cpp_errori_nid_postfix(int code) {
     ThrowCppError_nid_no_patch(code);
 }
@@ -537,6 +532,10 @@ void* APS5_VABI _Thrd_current_nid_postfix(void) {
     return ThreadForwards(__func__).self();
 }
 
+void* APS5_VABI _Thrd_id_nid_postfix(void) {
+    return ThreadForwards(__func__).self();
+}
+
 [[noreturn]] void APS5_VABI _Thrd_exit_nid_postfix(int code) {
     ThreadForwards(__func__).exit(reinterpret_cast<void*>(static_cast<std::uintptr_t>(static_cast<unsigned int>(code))));
     std::abort();

core/libs/tests/GuestLibcThreads.cpp

@@ -300,6 +300,7 @@ static void PadDetach() {
 
 static void KernelKeys() {
     Require(_Thrd_current_nid_postfix() == scePthreadSelf());
+    Require(_Thrd_id_nid_postfix() == scePthreadSelf());
     int key = -1;
     Require(_Tss_create_nid_postfix(&key, nullptr) == success && key >= 0);
     int value = 0;
@@ -346,10 +347,12 @@ static void ForwardedCalls() {
     Require(_Tss_set_nid_postfix(8, &flag) == success && forwardLog.key == 8 && forwardLog.value == &flag);
     Require(_Thrd_equal_nid_postfix(&flag, &key) == 1 && forwardLog.first == &flag && forwardLog.second == &key);
     Require(_Thrd_current_nid_postfix() == &forwardLog.key);
+    Require(_Thrd_id_nid_postfix() == &forwardLog.key);
     Require(_Mtx_current_owns_nid_postfix(nullptr) == 1);
 
     RegisterThreadForwards_nid_no_patch(nullptr);
     RequireThrows<std::runtime_error>([] { _Thrd_current_nid_postfix(); });
+    RequireThrows<std::runtime_error>([] { _Thrd_id_nid_postfix(); });
     RequireThrows<std::runtime_error>([] { _Tss_get_nid_postfix(0); });
 }
 

docs/dev/debt/libc.md

@@ -162,7 +162,7 @@
 - [codecvt<wchar_t,char,_Mbstatet> vtable](../../../core/libs/prx/libc/src/LocaleSupport.cpp) (libc, NID `H-TDszhsYuY`) is thirteen zeroed `uintptr_t` slots matching `st_size` 104 on title `libc.prx` from PPSA26344 and on `libSceLibcInternal.sprx` (offset-to-top, typeinfo, two destructors, `_Incref`/`_Decref`, and seven conversion virtuals). Facet calls through the object fault until those methods are wired.
 - [num_put<wchar_t> vtable](../../../core/libs/prx/libc/src/LocaleSupport.cpp) (libc, NID `59oywaaZbJk`) is fourteen zeroed `uintptr_t` slots matching `st_size` 112 on the title `libc.prx` from PPSA16833 (offset-to-top, typeinfo, two destructors, `_Incref`/`_Decref`, and eight `do_put` virtuals). Facet calls through the object fault until those methods are wired.
 - [ios_base standard streams](../../../core/libs/prx/libc/src/LocaleSupport.cpp) (libc) `_Addstd` queues the stream in the standard stream table of Dinkumware [ios.cpp](https://github.com/ganboing/crt.vc12/blob/master/src/ios.cpp) (`stdstr`, `stdopens`, `_Addstd`, `_Ios_base_dtor`): it takes the first of slots 1 to 7 that is free or already holds the stream, and slot 8 (`NSTDSTR`) when none is, so slot 8 is shared by every stream past the first seven and registration never fails. It stores the 1-based slot index in the guest `IosBase::standardStream` (Dinkumware's `_Stdstr`, where 0 means not a standard stream) and counts the stream objects registered per slot; registering the same stream again reuses its slot and raises its count. Measured on a PS5 (firmware 13.60) from a homebrew payload calling the system `libSceLibcInternal` export: in a process whose own standard streams already hold slots 1 to 7, twelve distinct streams and a repeated one all get 8, written as a 64-bit value at offset 0x8 with no other byte of the object touched; the assignment of slots 1 to 7 to fresh streams is not observable there and follows VC12. The counts are `int`, not VC12's `char`, and the registration and the destructor lock the table where VC12 locks only `_Addstd`; a slot index past the table throws in the destructor instead of indexing out of bounds. The destructor decrements its slot's count and suppresses the rest of the destruction while the count stays positive, as `_Ios_base_dtor` does, and the slots of destroyed streams keep their pointer and stay reserved for that stream, as `stdstr` does. The streams themselves are destroyed by the title's own code as it registers them through `__cxa_atexit`; when the last reference closes, the unsupported stream storage and callback cleanup is still the throw it was and the locale is released as for a non-standard stream.
-- [std::_Pad, _Thrd_join, _Thrd_detach, _Thrd_id](../../../core/libs/prx/libc/src/Threads.cpp) (libc) follow Dinkumware V6.00 `thr/xthread` and `thr/threadcall.cpp` ([crt.vc12 `f1d47126`](https://github.com/ganboing/crt.vc12/tree/f1d47126/src/thr)), without console verification. `_Thrd_id` throws because whether the console returns `pthread_t` or a kernel thread ID and at what width is unknown; `_Launch` omits `_Cnd_do_broadcast_at_thread_exit` and calls `pthread_create` registered by libkernel with default attributes. The 32-byte pad layout (`_Go()` vtable at 0x0, `_Cnd_t` at 0x8, `_Mtx_t` at 0x10, `bool _Started` at 0x18) is assumed from VC12, unverified. Failing primitives or thread start throw the guest `std::system_error`; null arguments throw. `_Thrd_join` returns `_Thrd_error` (4) on `pthread_join` failure and truncates the exit code to `int`; `_Thrd_detach` returns `_Thrd_error` (4) on `pthread_detach` failure and throws when none is registered
+- [std::_Pad, _Thrd_join, _Thrd_detach, _Thrd_id](../../../core/libs/prx/libc/src/Threads.cpp) (libc) follow Dinkumware V6.00 `thr/xthread` and `thr/threadcall.cpp` ([crt.vc12 `f1d47126`](https://github.com/ganboing/crt.vc12/tree/f1d47126/src/thr)), otherwise without console verification. `_Thrd_id` returns `scePthreadSelf()` unchanged, as measured on a PS5 (firmware 13.40) in two threads (#4164, #8711); `_Launch` omits `_Cnd_do_broadcast_at_thread_exit` and calls `pthread_create` registered by libkernel with default attributes. The 32-byte pad layout (`_Go()` vtable at 0x0, `_Cnd_t` at 0x8, `_Mtx_t` at 0x10, `bool _Started` at 0x18) is assumed from VC12, unverified. Failing primitives or thread start throw the guest `std::system_error`; null arguments throw. `_Thrd_join` returns `_Thrd_error` (4) on `pthread_join` failure and truncates the exit code to `int`; `_Thrd_detach` returns `_Thrd_error` (4) on `pthread_detach` failure and throws when none is registered
 - [siginterrupt](../../../core/libs/prx/libc/src/Process.cpp) (libc) runs FreeBSD 11.4's `siginterrupt.c` sequence through the `sigaction` and the `_sigintr` set that libkernel registers at load: it reads the signal's disposition, sets or clears the signal's bit and `SA_RESTART`, and installs the disposition again. The set is written outside libkernel's registration lock, as FreeBSD's libc writes it without one; a call before libkernel has registered throws.
 - [collate<char> vtable](../../../core/libs/prx/libc/src/LocaleSupport.cpp) (libc, NID `ruZtIwbCFjk`) is nine zeroed `uintptr_t` slots matching `st_size` 72 on the title `libc.prx` from PPSA16833 (offset-to-top, typeinfo, two destructors, `_Incref`/`_Decref`, and three `do_*` virtuals). Facet calls through the object fault until those methods are wired; `_Getcat` still installs the host `g_collateVtable` for facets it builds.
 - [num_get<char>::id, time_get<char>::id and the num_get<char> vtable](../../../core/libs/prx/libc/src/LocaleSupport.cpp) (libc) are data objects, as the public SDK's libSceLibcInternal table declares them and as the other facet ids and the `num_put` and `codecvt` vtables are kept: the ids start at zero and the vtable is 17 zeroed slots, the 136-byte size of `KfcTPbeaOqg` in the console's libSceLibcInternal, whose relocations fill the offset-to-top and typeinfo entries, the two destructors, `locale::facet::_Incref` and `_Decref`, and the eleven `do_get` of Dinkumware's crt.vc12 `xlocnum`, so a guest resolves the symbols and reads data, and a facet call through the vtable faults. libSceAmpr exported the three as throwing functions, which a data consumer reads as code; its qualified imports fall back to libc.