On Tue, Jun 30, 2020 at 1:41 AM Borislav Petkov <bp@xxxxxxxxx> wrote: > > 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. I don't see the problem. If you call this magic vDSO function and get a fault, it gets handled. What's the failure mode? > > > 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? Don't forget the cross-arch issue. We need that structure to have constant layout so that the -m32 build from the vDSO has the same layout as in the kernel. So my only actual objection to the patch is that there should probably be a comment above the structure reminding people that it needs to have the same layout on 32-bit, x32, and x86_64. So maybe the entries should be s32 instead of int, although this doesn't really matter.
