Re: [patch 16/18] x86/entry: Get rid of the sys_ni_syscall() indirection

[Sebastian Andrzej Siewior]

On 2026-10-23 16:24:22 [+0200], Thomas Gleixner wrote:
> IOW, a tracer modification of regs->ax is not overwritten when the
> syscall number is out of range.
> 
> Between 2.6.19-rc2 and -rc3 x86_64 was changed to _always_ overwrite
> regs->ax when the syscall number is out of range.
> 
> In the 3.8 merge window seccomp introduced the -1 == skip bogosity which
> got fixed up and made "consistent" in several changes afterwards. Just
> that it never reached a state of consistency due to the overloading.
> 
> So are we stuck with this behavior or do we sit down and define what the
> correct behavior should be?

I wouldn't say we are stuck. The test did reassemble the status we had
at the moment. As you wrote yourself the behaviour changed a few times
and not on purpose.
I would say we define what correct behaviour should be and make sure it
is consistent across all the architectures.

> Thanks,
> 
>         tglx

Sebastian