[PATCH] x86: Check invalid TLS descriptor call

[H.J. Lu]

On Sat, Aug 31, 2024 at 4:07 AM Alexandre Oliva <oliva@gnu.org> wrote:
>
> On Aug 29, 2024, "H.J. Lu" <hjl.tools@gmail.com> wrote:
>
> > TLS descriptor call,
> > call *x@tlsdesc(%rax)
>
> > or
>
> > call *x@tlsdesc(%eax)
>
> > calls _dl_tlsdesc_return which expects that RAX/EAX points to the TLS
> > descriptor.
>
> But it doesn't follow that one must not use any other register that
> holds a copy of %[er]ax for the call, does it?
>

Did you mean that

lea foo@tlsdesc(%ebx), %eax
mov %eax, %ecx
call *foo@tlscall(%ecx)

also works?

-- 
H.J.