Re: Official Linux system wrapper library?

Joseph Myers
2018-11-14T18:30:35Z

On Wed, 14 Nov 2018, Arnd Bergmann wrote:

> Firoz Khan is in the process of doing part of this, by changing the
> in-kernel per-architecture unistd.h and syscall.S files into a
> architecture independent machine-readable format that is used to
> generate the existing files. The format will be similar to what
> we have on arm/s390/x86 in the syscall.tbl files already.

Will this also mean the following are unable to occur in future (both have
occurred in the past):

* A syscall added to unistd.h for an architecture, but not added to the
syscall table until sometime later?

* A syscall added to the native syscall table for some ABI (e.g. 32-bit
x86 or arm) but not added to the corresponding compat syscall table (e.g.
32-bit x86 binaries running on x86_64, 32-bit arm binaries running on
arm64) until sometime later?

Avoiding both of those complications is beneficial to libc (as is a third
thing, avoiding a syscall being added to different architectures in
different versions).

--
Joseph S. Myers
joseph@codesourcery.com