Re: [PATCH v11 25/25] x86/cet/shstk: Add arch_prctl functions for shadow stack

Florian Weimer
2020-08-27T13:29:09Z

* Dave Martin:

> You're right that this has implications: for i386, libc probably pulls
> more arguments off the stack than are really there in some situations.
> This isn't a new problem though. There are already generic prctls with
> fewer than 4 args that are used on x86.

As originally posted, glibc prctl would have to know that it has to pull
an u64 argument off the argument list for ARCH_X86_CET_DISABLE. But
then the u64 argument is a problem for arch_prctl as well.

Thanks,
Florian