Re: [PATCH v33 15/21] x86/vdso: Add support for exception fixup in vDSO functions

Borislav Petkov
2020-06-30T08:41:39Z

On Mon, Jun 29, 2020 at 11:00:55PM -0700, Sean Christopherson wrote:
> E.g. the vDSO function should get the fixup even if userspace screws
> up mmap() and invokes __vdso_sgx_enter_enclave() without being tagged
> an SGX task.

I sincerely hope you don't mean this seriously.

Please add a member to task_struct which denotes that a task is an
sgx task, test that member where needed and forget real quickly about
running *any* *fixup* for unrelated tasks.

> No hard dependency, it's normal kernel code. My reasoning for dropping it
> in .../vdso was largely to co-locate it with vdso/extable.h due to the
> dependency on the format of 'struct vdso_exception_table_entry'.

A struct which you defined instead of simply using struct
exception_table_entry even if it has a handler member which would remain
unused?

Let's not put code in vdso/ if it doesn't really belong there pls.

> Ya, shouldn't be a problem to stub it out for SGX=n.

Thx.

--
Regards/Gruss,
Boris.