Messages in this thread | | | Date | Wed, 27 Jan 2016 11:05:45 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86/mm: avoid premature success when changing page attributes |
| |
On Mon, 25 Jan 2016, Jan Beulich wrote:
Sorry, that changelog does not make any sense.
> Since successful return from __cpa_process_fault() makes > __change_page_attr() exit early (and successfully), its caller needs to
That has nothing to do with a successful return from __cpa_process_fault().
__change_page_attr() always returns immediately after calling __cpa_process_fault() no matter what the return code is.
> be instructed to continue its iteration by adjusting ->numpages.
And how is that instruction working?
> While this already happens on one of __cpa_process_fault()'s successful exit > paths, the other needs this done similarly.
Why?
> This was in particular a problem when the top level caller passed zero for > "checkalias" (becoming the "primary" value for the other two mentioned > functions), as is the case in change_page_attr_set_clr() when the OR of > "mask_set" and "mask_clr" equals _PAGE_NX, as e.g. passed from > set_memory_{,n}x().
This is completely unparseable.
Can you please describe the failure and the solution in a way, which lets one figure out what that means w/o studying the code in detail?
Thanks,
tglx
| |