[PATCH v5 0/6] x86/cet: Update CET kernel interface

[H.J. Lu]

On Thu, Dec 28, 2023 at 8:00 AM Florian Weimer <fw@deneb.enyo.de> wrote:
>
> * H. J. Lu:
>
> > H.J. Lu (6):
> >   x86/cet: Sync with Linux kernel 6.6 shadow stack interface
> >   elf: Always provide _dl_get_dl_main_map in libc.a
> >   x86/cet: Enable shadow stack during startup
> >   x86/cet: Check feature_1 in TCB for active IBT and SHSTK
> >   x86/cet: Don't set CET active by default
> >   x86/cet: Run some CET tests with shadow stack
>
> I tested this on:
>
> vendor_id       : AuthenticAMD
> cpu family      : 25
> model           : 97
> model name      : AMD Ryzen 9 7950X 16-Core Processor
> stepping        : 2
> microcode       : 0xa601206
>
> and the CET tests pass, except elf/tst-cet-legacy-8 and
> elf/tst-cet-property-2, which are flagged as UNSUPPORTED because IBT
> is not available (as expected).

Thanks for your feedback.

> What's missing is a fault test that verifies that an unmatched RET
> instruction results in a SIGSEGV with a code of SEGV_CPERR, but that
> can be added later.

We could add more shadow stack tests after the shadow stack is enabled.

I will submit a patch to allow mixing longjmp with user contexts.

I will check in the v5 patch series next week if there are no objections so
that we can start validating shadow stack support in applications and libraries.

-- 
H.J.