libkernel numbered guest sockets from GuestSockets::FirstDescriptor
(0x10000000), so a title that puts a socket in a 1024-bit fd_set writes
fd / 8 bytes past it. The Epic Online Services SDK does this on its
RtcNetworkThread and three titles stop there (#1794):
Palworld PPSA23126 (queeeef, main a11c8f7f7):
FATAL: unhandled exception 0xc0000005 on thread 37164 'RtcNetworkThread'
rip 0x00007ffcdb1ea2be eossdk-ps5-shipping.prx.guest.prx+0xdea2be
rcx 0000000010000005 rsi 0000000000400000 r12 0000000010000005
The Mound PPSA26223 (xXPBSXx, main 0a8b1d32b):
FATAL: unhandled exception 0xc0000005 on thread 'RtcNetworkThread',
rip eossdk-ps5-shipping.prx.guest.prx+0xefc6f4, rcx = 0x10000005,
rsi = 0x400000
Dying Light 2 PPSA02262 (tv7):
FATAL: unhandled exception 0xc0000005 on thread 'RtcNetworkThread'
rcx 0000000010000005 ... rsi 0000000000400000 ... r12 0000000010000005
On FreeBSD 11.4 (8c639945) FD_SETSIZE is 1024 (sys/sys/select.h:58-59)
and sockets take the lowest free entry of the one process descriptor
table that files use (kern_descrip.c:1643-1660 fdalloc,
uipc_syscalls.c kern_socket through falloc).
Every socket number is now a real host descriptor: a zero-access NUL
handle registered with _open_osfhandle on Windows (as directory
descriptors already are) and an F_DUPFD_CLOEXEC duplicate of the host
socket on Linux. The socket table maps that number to the socket, so
"is this a socket" is a table lookup instead of a range check at the 31
former FirstDescriptor comparisons. close releases both the socket entry
and the number, dup and dup2 duplicate the number through the host table
and keep the socket shared, dup2 of a file onto a socket number drops the
socket entry, and sceKernelClose now closes sockets too. sceNetSocket and
sceNetAccept take their ids from the same table instead of a counter from
32, so libkernel and libSceNet numbers never collide.
select polls guest sockets alongside libSceNet sockets, the random device,
stdio and (on Linux) host descriptors; poll throws only for an open
descriptor that is not a guest socket and reports POLLNVAL otherwise.
File calls that used to fail with EBADF on the socket range return
FreeBSD's answer for a socket: lseek ESPIPE (kern_lseek), ftruncate and
getdirentries EINVAL (invfo_truncate, getvnode), flock EOPNOTSUPP;
fstat on a socket throws. pread on a closed descriptor returns EBADF.
title failing on host descriptor numbers; these three titles are that
case, and this change keeps host numbering for files and only moves
sockets into it.
Tests: guest_socket_descriptors (new: socket below 1024, select on a
socket and a file together, close frees the number for a file, dup of a
socket, sceKernelClose), guest_select (socket and pipe together, Linux),
guest_poll, guest_dup, guest_socket_pair, guest_fstatfs,
guest_posix_filesystem and guest_sce_net updated.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
(cherry picked from commit 20378375b31eb5db922db6e55f45e44a4dae6445)
fcntl and sceKernelFcntl answered EBADF (sceKernelFcntl threw) for
every descriptor outside the libSceNet socket table, so files, pipes,
directories and descriptors 0 to 2 could not be queried or changed.
Observed: Yamagi Quake II (PPSA99007) stops with
"Sys_Error: change stdin to blocking Bad file descriptor", from
fcntl(fileno(stdin), F_SETFL, fcntl(0, F_GETFL, 0) & ~FNDELAY)
(yquake2 src/backends/unix/system.c:81-86).
Predicted from the titles' sources and decoded call sites: XPSemu
(PPSA97358, 97 fcntl sites: F_GETFD 12, F_SETFD 20, F_GETFL 8,
F_SETFL 9, F_DUPFD 1, F_DUPFD_CLOEXEC 7, F_GETLK 9) fails in
qemu_init_main_loop, where its pipe2 (pipe plus F_SETFD FD_CLOEXEC) and
glib's g_unix_set_fd_nonblocking (F_GETFL, F_SETFL) build the event
notifier (util/event_notifier-posix.c:44-67); VLC (PPSA85300, 43 sites,
F_RDAHEAD on every file it opens), RetroArch (PPSA99169, 17),
Porpoise (PPSA99764, 13) and Ruffle (9) call it on files and pipes.
The commands follow FreeBSD 11.4 kern_fcntl and kern_dup
(sys/kern/kern_descrip.c:479-799, 812, release/11.4.0 8c639945):
F_GETFD/F_SETFD keep the close-on-exec flag per descriptor, F_GETFL
reports the host access mode with the status flags, F_SETFL changes
only O_NONBLOCK, O_APPEND, O_ASYNC, O_FSYNC, O_DIRECT and FRDAHEAD,
F_DUPFD/F_DUPFD_CLOEXEC give the lowest free descriptor at or above the
start through dup (EINVAL for a negative start), F_DUP2FD goes through
dup2, F_RDAHEAD/F_READAHEAD set FRDAHEAD on files (EBADF on pipes,
ENOTTY elsewhere), and unknown commands fail with EINVAL. Status flags
live in a guest table shared by dup, dup2 and F_DUPFD like an open file
description. O_NONBLOCK switches a pipe (PIPE_NOWAIT on Windows, where an
empty read and a full write now report EAGAIN; the host flag on Linux).
Record locks use the host POSIX locks on Linux and throw on Windows.
Changes the host cannot model throw naming the flag and descriptor kind.
Sockets keep their path unchanged.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
close() of a descriptor that is not open calls _close, which raises the
UCRT invalid-parameter handler before returning EBADF. In a relinked title
that handler is libc's crash reporter, so an ordinary close of a closed
descriptor printed a FATAL report and every thread's stack. The call now
runs with the thread-local no-op handler, as dup and dup2 already do.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>