sceSystemServiceLoadExec found its own executable through /proc/self/exe
and replaced the process with fexecve after close_range, none of which
macOS has, so on macOS every call except "exit" threw. On macOS:
- the running executable's path comes from _NSGetExecutablePath, resolved
with std::filesystem::canonical, as libSceNpEntitlementAccess and
libSceFont already do;
- the target must be an x86-64 Mach-O executable (MH_MAGIC_64,
CPU_TYPE_X86_64, MH_EXECUTE) that the user may run;
- macOS has no fexecve, so the process is replaced by path with
posix_spawn and POSIX_SPAWN_SETEXEC; POSIX_SPAWN_CLOEXEC_DEFAULT closes
every descriptor but the standard streams, as close_range does on Linux;
- before the replacement the exit starts and the shutdown callbacks run
(LibcStartExit, then LibcRunShutdown), as on Linux, so guest threads
that call a stopped library wait instead of unwinding;
- descriptor 2 gets the host standard error back before the replacement,
as on Linux, and guest_system_load_exec_standard_error runs on macOS.
A launch without arguments keeps the Linux execv path, which macOS has.
guest_system_exit finds its own executable the same way on macOS.
Metal Gear Solid 4 (PPSA18194) aborts on main when its launcher starts
the game: sceSystemServiceLoadExec runs the guest shutdown, a render
thread that then calls into the stopped AGC driver gets ProcessShutdown
back from LibcAwaitExit, and the exception unwinds into title code,
which terminates the process before the new executable starts.
LibcAwaitExit parks a thread only once an exit has been requested, and
LoadExec ran the shutdown without requesting one. It now starts the
shutdown the way exit does, so such threads wait until the process is
replaced.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A guest handler that called exit threw out of the libc exit path because the exiting thread waited on itself. Like FreeBSD, the nested call now runs the handlers that are still registered and ends the process with the status it passed.
The relinker's repeatable --executable converts another executable of the
title beside the output, sharing its libs, app0 and guest modules.
sceSystemServiceLoadExec maps /app0 paths to those executables, passes the
argument list on the new command line and finds the main executable through
APS5_EBOOT. RetroArch (PPSA99169) starts its frontend picker this way.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
On Windows std::_Exit ends in ExitProcess, which still runs every module's
DLL_PROCESS_DETACH and TLS callbacks after the other threads are gone. A
static destructor that joins a worker then waits forever: a title that calls
_Exit while libSceVideoOut's flip queue runs (ps5-opengl's retirement
fail-stop) stays alive in FlipQueue's destructor. _Exit and libkernel's _exit
now terminate the process with TerminateProcess, as _exit ends a POSIX
process: no atexit handlers, stream flushes or module destructors.
Dean