Reported by jamesob on IRC, see https://gist.github.com/jamesob/c46513d41e355a3e6e69f4ff78167c92

I'm still thinking we might want to remove the syscall name table, and replace it with instructions how to look up the number (e.g. as argued here #20487 (comment)). Having this list of syscall constants we don't actually use, besides for error reporting, seems asking for more and more PRs like this.
(another options would be to #ifdef every single one, but this is very verbose… and would make it hard to find actual problems in it)

Concept ACK

What we also could do is add an autoconf test, and fail the --with-seccomp check below a certain lower bound kernel header version (or easier to detect, when a certain syscall is not in the header).

cr ACK ac402e7

Thanks for quickly addressing this!

This might be helpful to fellow reviewers:

$ grep -E 'copy_file_range$' linux/arch/x86/entry/syscalls/syscall_64.tbl
326     common  copy_file_range         sys_copy_file_range

Some syscall history:

The newest syscall in the LINUX_SYSCALLS map is arch_prctl which was introduced in Linux 4.12 (2017).

These syscalls were introduced from Linux 3.17 (2014) to Linux 4.12 (2017):

• Linux 3.17 (2014): getrandom, kexec_file_load, membarrier, memfd_create, seccomp
• Linux 3.18 (2014): bpf
• Linux 3.19 (2014): execveat
• Linux 4.0 (2015): -
• Linux 4.1 (2015): -
• Linux 4.2 (2015): -
• Linux 4.3 (2015): userfaultfd
• Linux 4.4 (2016): mlock2
• Linux 4.5 (2016): copy_file_range
• Linux 4.6 (2016): preadv2, pwritev2
• Linux 4.7 (2016): -
• Linux 4.8 (2016): pkey_alloc, pkey_free, pkey_mprotect
• Linux 4.9 (2016): -
• Linux 4.10 (2017): -
• Linux 4.11 (2017): statx
• Linux 4.12 (2017): arch_prctl (arch_prctl has been available for x64_64 since 2.6, x86 since 4.12)

Source: https://man7.org/linux/man-pages/man2/syscalls.2.html

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

Conflicts

Reviewers, this pull request conflicts with the following ones:

• #23198 (build: Parse version information in msvc-autogen.py by CallMeMisterOwl)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

Guix builds

Some additional review comments:

I've done some additional digging and Linux 4.4 (2016) is the oldest kernel that is not EOL.

Thus it should only be the syscalls introduced after Linux 4.4 that are part of the LINUX_SYSCALLS map that might cause compile-time errors due to __NR_<syscall> being undefined (on supported non-EOL systems).

This should be the complete list of such syscalls:

• Linux 4.5 (2016): copy_file_range
• Linux 4.6 (2016): preadv2, pwritev2
• Linux 4.8 (2016): pkey_alloc, pkey_free, pkey_mprotect
• Linux 4.11 (2017): statx
• Newer syscalls are not included as part of LINUX_SYSCALLS. Note that LINUX_SYSCALLS is only used for friendly printing of syscall names, and thus it doesn't need to be complete with the most recently introduced syscalls. If a syscall is not present in LINUX_SYSCALLS the syscall number will be printed in error messages, but not the syscall name.

All the syscalls listed above are covered (either via #define or #ifdef) after the merge of this PR.

Thus we shouldn't see any more compile-time issues on supported non-EOL systems after the merge of this PR :)

@practicalswift Whoa, thanks for doing some software archeology there.

Thus we shouldn't see any more compile-time issues on supported non-EOL systems after the merge of this PR :)

I think the main users of EOL kernels are people stuck with the vendor kernel for some embedded board. But even if ARM would be supported for sandboxing, it's always possible to disable it with configure, it's not like this prevents compilation altogether.