> On Oct 25, 2021, at 10:45 AM, Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > > On 10/25/21 9:19 AM, Nadav Amit wrote: >> That was my first version, but I was concerned that perhaps there is >> some strange scenario in which both X86_PF_WRITE and X86_PF_INSN can >> be set. That is the reason that Peter asked you whether this is >> something that might happen. >> >> If you confirm they cannot be both set, I would the version you just >> mentioned. > > I'm pretty sure they can't be set together on any sane hardware. A > bonkers hypervisor or CPU could do it of course, but they'd be crazy. > > BTW, feel free to add a WARN_ON_ONCE() if WRITE and INSN are both set. > That would be a nice place to talk about the assumption. > I can do that. But be aware that if the assumption is broken, it might lead to the application getting stuck in an infinite loop of page-faults instead of receiving SIGSEGV.
