[zmeizy]

What

SceErrorFromErrno in libkernel/File/src/Stdio.cpp builds 0x80020000 | errno from the host errno. It passes values up to 34 through unchanged and turns everything else into EIO. Up to 34, Linux and FreeBSD numbering agree except for 11: Linux EAGAIN is 11, which is FreeBSD EDEADLK. Above 34 the two differ, so real errors were reported as EIO. For example, a non-blocking sceKernelReadv on an empty pipe returned 0x8002000b (EDEADLK) instead of 0x80020023 (EAGAIN). sceKernelMkdir with a too-long name returned EIO instead of ENAMETOOLONG (0x8002003f). The POSIX wrappers derive the guest errno from these codes, so readv and mkdir reported the wrong errno as well.

This maps the host values that differ to their FreeBSD numbers, using the host's own macros, so the mapping is the same on Linux and Windows:

• EAGAIN → 35
• EDEADLK → 11
• ENAMETOOLONG → 63
• ENOTEMPTY → 66
• ELOOP → 62
• EDQUOT → 69
• EOVERFLOW → 84

Values up to 34 still pass through, and anything else still becomes EIO. The guest constants the file passes in itself are unchanged.

Sources: FreeBSD sys/sys/errno.h for the guest numbers. Open.cpp's SceIoErrorFromErrno already applies the same values for EAGAIN, EDEADLK, EDQUOT and EOVERFLOW.

Related: #2144 rewrites the separate mapping in Open.cpp; this PR changes only Stdio.cpp's. Both add an ErrorEagain constant and #include <fcntl.h> to GuestFileVector.cpp (#2144 for sceKernelRead, this PR for sceKernelReadv), so whichever merges second drops the duplicate constant.

Tested

Ubuntu 24.04, GCC 13.3, on main a11c8f7f.

• guest_file_vector: new check that a non-blocking sceKernelReadv on an empty pipe returns 0x80020023 and readv sets errno 35 (skipped on Windows, which has no O_NONBLOCK pipes).
• guest_filesystem: new check that sceKernelMkdir with a 300-character name returns 0x8002003f and mkdir sets errno 63.
• Both tests abort on main without the change and pass with it.
• Full ctest --timeout 120 --parallel 4 with the change: 832 tests. 4 fail, none related to this change:
  • guest_truncate: the container runs as root, which ignores the read-only bit.
  • guest_kernel_stack_protect: also fails on main; fix(libc): resume host foreign exceptions with host unwinder #3520 fixes it.
  • Two lavapipe image-sampling tests.

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 (n/a)
• 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 (n/a)
• Generic behaviour, not specific to one title
• Depends on: none
• AI-assisted: yes

🤖 Generated with Claude Code

https://claude.ai/code/session_01Ha6Tsy62AFUyp9a5Mf7vjA

[adriadam10]

Checked the errno mapping against FreeBSD sys/sys/errno.h (EAGAIN 35, EDEADLK 11, ENAMETOOLONG 63, ELOOP 62, ENOTEMPTY 66, EDQUOT 69, EOVERFLOW 84) and against Open.cpp's existing mapping; build and ctest of core/libs pass, and both new checks fail when the Stdio.cpp change is reverted. Merging.