[jagrat04]

What

Fixes #3253. Refs #1578.

Carries pushkarreddyy's ready branch from #3253 rebased onto main with authorship intact.

Titles cataloged in #1578 and POSIX homebrew ports require signal set inspection and suspension exports: sigpending (NID hpoDTzy9Yy0) and sigsuspend (NID KZ-4qlqlpmo). While _sigprocmask, sigaction, and sigaltstack are present, sigpending and sigsuspend were absent in libkernel.

• sigpending_nid_postfix: checks pointer for null (EFAULT 14); clears returned signal set (as no asynchronous pending signals queue is maintained); preserves guest errno.
• sigsuspend_nid_postfix: checks mask pointer for null (EFAULT 14); names the mask in NotImplemented_nid_no_patch.
• Technical debt documented in TechnicalDebt.md.

Tested

• Extended core/libs/tests/GuestSignals.cpp unit test suite covering null pointer rejection, sentinel errno preservation, and NotImplemented_nid_no_patch throw.
• python tools/check_conventions.py --base origin/main passed cleanly with 0 errors.

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 in TechnicalDebt
• 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
• AI-assisted: yes

[github-actions]

Progress report (682ef0c → 0124a49)

📉 System libraries: 86.34% (-0.02%, +1 implemented, +1 declared functions)

✅ 1 implemented

Library	Name
libkernel	sigpending_nid_postfix

🆕 1 declared as stubs

Library	Name
libkernel	sigsuspend_nid_postfix

[github-actions]

Other open pull requests touch the same code. Merging one will break the other, or both implement the same thing. If this one builds on them, list them in Depends on.

Pull request	Conflicting files (lines on main)	Same exports	Same new files
#4383		sigpending_nid_postfix sigsuspend_nid_postfix
#4481	docs/dev/debt/libkernel.md L126-127
#4533	docs/dev/debt/libkernel.md L126-127

[pushkarreddyy]

Hi @jagrat04, thank you for carrying! I had already reopened, rebased, and addressed review feedback (naming the mask in sigsuspend, documenting Dispatch drop semantics in TechnicalDebt.md, MinGW GCC fixes) in #4383 earlier today. Since #4383 is active and passing all CI checks, could you please close #4541 to resolve the duplicate PR overlap? Thank you!

[xXPBSXx]

Windows test: head d74a08338 merged onto current main 2a5eca11c (clean merge, no conflicts). Windows 10, MinGW GCC (WinLibs), Ninja Release, -j2: full build 0 errors; ctest with the filter guest_signal: guest_signals passed, guest_signal_sets passed (2 test(s), 0 failed); python tools/check_conventions.py --base upstream/main passed. I did not run the new tests against main without the change.

AI-assisted (Claude Code).

[jagrat04]

Closing in favor of active PR #4383 by @pushkarreddyy.