[alnsx]

What

select and poll applied the standard-stream fallback before checking whether descriptors 0–2 referred to files. An empty file duplicated onto stdin therefore reported no readiness, even at EOF.

Check for a vnode first, so redirected files use the same readiness rules as files at any other descriptor. Tests cover all three standard descriptors, read/write readiness, exclusion of priority events, EOF and stream restoration.

This follows the existing FreeBSD model: selscan polls the file object and vop_stdpoll supplies ordinary read/write readiness. This also applies to files inherited through host redirection. Console behavior remains unmeasured.

Tested

Linux 7.2.6, GCC 13.3, Release; base e13027a1f399062d663d095ab1db139b91de0887, SPIRV-Tools disabled.

• Both new regressions fail with the base implementation: select returns 0 instead of 2; poll returns 0 instead of 1.
• With the fix, 8/8 focused tests pass: select, poll, filesystem, socket descriptor flags, three standard-stream cases and kqueue.
• All libraries and the relinker rebuild successfully. Whitespace and scoped conventions checks pass; debt-length warnings remain.
• After merging main 0119103fa9, head 7eecb44157 rebuilds all libraries/relinker and passes the same 8 focused tests (Linux, 2026-10-25). This includes the merged docs(libkernel): correct three stale socket statements #9365 documentation corrections.
• Windows, macOS and console execution not tested; no game-unblocking claim.

ctest --test-dir build -R '^(guest_select|guest_poll|guest_filesystem|guest_standard_streams.*|guest_kqueue|guest_socket_descriptor_flags)$' -V

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw (NotImplemented_nid_no_patch); silent stubs are listed under Silent stubs in their library's technical debt file
• No notes, investigation .md files or images added to the repository (attach them to this PR)
• New third-party code is a submodule built from source
• Generic behaviour, not specific to one title
• Depends on: none
• Fixes: none
• Unblocks: none
• GPUs tested: n/a
• AI-assisted: yes

[github-actions]

Some comparisons could not be completed because a pull request conflicts with the base branch. Review these shared files manually before concluding that there is no overlap.

Pull request	Shared files not compared
PR 4630	docs/dev/debt/libkernel.md
PR 5021	core/libs/prx/libkernel/Socket/src/Udp.cpp docs/dev/debt/libkernel.md
PR 6149	docs/dev/debt/libkernel.md
PR 6740	docs/dev/debt/libkernel.md
PR 6830	docs/dev/debt/libkernel.md
PR 6936	docs/dev/debt/libkernel.md
PR 7088	core/libs/prx/libkernel/Socket/src/Udp.cpp docs/dev/debt/libkernel.md
PR 7105	docs/dev/debt/libkernel.md
PR 7121	docs/dev/debt/libkernel.md
PR 7149	docs/dev/debt/libkernel.md
PR 7192	docs/dev/debt/libkernel.md
PR 7201	core/libs/prx/libkernel/Socket/src/Udp.cpp core/libs/tests/GuestPoll.cpp
PR 7447	docs/dev/debt/libkernel.md
PR 7475	core/libs/prx/libkernel/Socket/src/Udp.cpp
PR 7509	docs/dev/debt/libkernel.md
PR 7804	docs/dev/debt/libkernel.md
PR 8010	docs/dev/debt/libkernel.md
PR 8520	docs/dev/debt/libkernel.md
PR 8605	core/libs/prx/libkernel/Socket/src/Udp.cpp docs/dev/debt/libkernel.md
PR 9156	docs/dev/debt/libkernel.md
PR 9199	docs/dev/debt/libkernel.md
PR 9242	docs/dev/debt/libkernel.md
PR 9284	docs/dev/debt/libkernel.md
PR 9293	docs/dev/debt/libkernel.md
PR 9297	docs/dev/debt/libkernel.md
PR 9302	docs/dev/debt/libkernel.md
PR 9389	docs/dev/debt/libkernel.md
PR 9509	core/libs/prx/libkernel/Socket/src/Udp.cpp docs/dev/debt/libkernel.md
PR 9557	docs/dev/debt/libkernel.md
PR 9566	docs/dev/debt/libkernel.md
PR 9575	docs/dev/debt/libkernel.md
PR 9669	docs/dev/debt/libkernel.md
PR 9684	docs/dev/debt/libkernel.md
PR 9713	core/libs/prx/libkernel/Socket/src/Udp.cpp
PR 9938	docs/dev/debt/libkernel.md
PR 9948	core/libs/prx/libkernel/Socket/src/Udp.cpp
PR 10061	docs/dev/debt/libkernel.md
PR 10442	docs/dev/debt/libkernel.md
PR 10499	docs/dev/debt/libkernel.md
PR 10501	docs/dev/debt/libkernel.md
PR 10621	core/libs/prx/libkernel/Socket/src/Udp.cpp docs/dev/debt/libkernel.md
PR 10666	docs/dev/debt/libkernel.md
PR 10749	docs/dev/debt/libkernel.md
PR 10898	docs/dev/debt/libkernel.md
PR 11002	docs/dev/debt/libkernel.md
PR 11042	docs/dev/debt/libkernel.md
PR 11047	docs/dev/debt/libkernel.md

[harisibrar1]

Checked against main 6c52b64 and FreeBSD 11.4 vop_stdpoll/selscan:

• The reorder looks right to me. File::IsVnode only accepts regular files, directories and archived files (S_ISREG/S_ISDIR on Linux, FILE_TYPE_DISK on Windows), so a pipe or terminal on 0-2 still takes the standard-stream fallback, and the vnode readiness matches vop_stdpoll (no POLLPRI, no POLLHUP).
• One behaviour change I'd like spelled out in the debt: IsVnode can't tell a guest dup2 from a host redirection. Launching with < file on Linux now makes fd 0 always readable, and Dungeons (PPSA16064) selects on fd 0, so it would start reading host stdin. With > log.txt, fd 1 and 2 become readable too. Main's poll entry (docs/dev/debt/libkernel.md:213) still says 0-2 follow the console model "whatever the host attaches to them", which is no longer true for files. Could that line be updated together with the select one?
• The rewritten select entry drops two sentences that still describe current code: the /dev/random/randomdev_poll set-reporting rule and the kqueue_poll sentence. Could they be kept, with only the standard-descriptor part changed?
• The branch merges cleanly with current main. #10501's pselect goes through select_nid_postfix, so it picks this up; #9945's NUL handles are character devices and keep the fallback (from reading only, not run on Windows).

Reviewed with AI assistance (Claude Code); the checks above were run locally on my machine.

[alnsx]

Thanks for the review. Updated the debt entries to cover host redirection and kept the random-device and kqueue descriptions.

#9365 is now merged and included, and this branch merges cleanly. All libraries and the relinker rebuild on Linux; all 8 focused tests pass at 7eecb44157.

Could you take another look? Could a maintainer also run the full Linux/Windows CI for this head? Windows hasn’t been tested locally.

[orezraey]

@alnsx #11247 rewrites the Windows poll debt entry and removes the Linux one right after the entry this PR edits in docs/dev/debt/libkernel.md (stream socket resets and half-closes, now measured on a PS5), and changes poll_nid_postfix's collect step. Git may report a conflict; whichever merges second keeps both, and I'll rebase #11247 if this one lands first.