On 09/07/2018 03:48 PM, Andy Lutomirski wrote: >> >> For part of the page fault handler, "error_code" does exactly >> match PFEC. But, during later parts, it diverges and starts to >> mean something a bit different. >> >> Give it two names for its two jobs. > How hard would it be to just remove sw_error_code instead? It seems > like it adds little value and much confusion.
I think it would be really nice to have hw_error_code stand by itself and be limited in scope to just __do_page_fault() and then have FAULT_FLAG_* for everything else. But, I was a little scared off of that. For one, I think we fill in signal info with error_code, which makes it nominally part of the ABI. So, I wanted to muck with it as little as possible in this set. But, if we just said that 1. hw_error_code goes out to userspace, always, and 2. We drive all kernel behavior off of FAULT_FLAG_*, not error_code, I think we can get away with it. > I’m also unconvinced that the warning is terribly useful. We’re going > to oops when this happens anyway. One thing I wanted to get out of the warning was the contents of hw_error_code before we go screwing with it. I also don't mind a nice, clarifying warning showing up just before an oops. Maybe it could be a pr_warn/err() instead of a full warning?
