Messages in this thread | | | Date | Wed, 25 Jun 2014 14:43:13 -0700 | From | Dave Hansen <> | Subject | Re: [PATCH v6 02/10] x86, mpx: add MPX specific mmap interface |
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On 06/25/2014 02:04 PM, Andy Lutomirski wrote: > On Tue, Jun 24, 2014 at 6:40 PM, Ren, Qiaowei <qiaowei.ren@intel.com> 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.
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