Re: [PATCH v6 02/10] x86, mpx: add MPX specific mmap interface
From: Dave Hansen
Date: Wed Jun 25 2014 - 17:43:20 EST
On 06/25/2014 02:04 PM, Andy Lutomirski wrote:
> On Tue, Jun 24, 2014 at 6:40 PM, Ren, Qiaowei <qiaowei.ren@xxxxxxxxx> wrote:
>> Hmm, _install_special_mapping should completely prevent merging, even among MPX vmas.
>>
>> So, could you tell me how to set MPX specific ->name to the vma when it is created? Seems like that I could not find such interface.
>
> You may need to add one.
>
> I'd suggest posting a new thread to linux-mm describing what you need
> and asking how to do it.
I shared this with Qiaowei privately, but might as well repeat myself
here in case anyone wants to set me straight.
Most of the interfaces do to set vm_ops do it in file_operations ->mmap
op. Nobody sets ->vm_ops on anonymous VMAs, so we're in uncharted
territory.
My suggestion: you can either plumb a new API down in to mmap_region()
to get the VMA or set ->vm_ops, or just call find_vma() after
mmap_region() or get_unmapped_area() and set it manually. Just make
sure you still have mmap_sem held over the whole thing.
I think I prefer just setting ->vm_ops directly, even though it's a wee
bit of a hack to create something just to look it up a moment later.
Oh, well.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/