Re: [PATCH] x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space

[Joerg Roedel]

On Thu, Apr 20, 2017 at 08:45:28AM -0700, Dave Hansen wrote:
> How about doing X86_TRAP_PF?  That would at least be consistent with
> SIGBUS, which is probably the closest thing to a generic error code that
> we have.

Correct me if I am wrong, but for SIGBUS this only happens in the
page-fault path, right? And this path is indeed entered on a #PF
exception.

I see no reason to lie to user-space about the trap_nr that caused the
SIGSEGV, especially since user-space software needs to be modified to
make use of MPX, including the signal handler. So there is no risk of
introducing any incompatibility or regression, no?


	Joerg