Messages in this thread | | | Subject | Re: [PATCHv2 3/6] x86/arch_prctl/vdso: add ARCH_MAP_VDSO_* | From | Dmitry Safonov <> | Date | Tue, 2 Aug 2016 13:59:40 +0300 |
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On 07/12/2016 05:14 PM, Oleg Nesterov wrote: > On 07/11, Andy Lutomirski wrote: >> I'm starting to wonder if we should finally suck it up and give >> special mappings a non-NULL vm_file so we can track them properly. >> Oleg, weren't you thinking of doing that for some other reason? > > Yes, uprobes. Currently we can't probe vdso page(s).
So, to make sure, that I've understood correctly, I need to: o add vm_file to vdso/vvar vmas, __install_special_mapping will init them; o place array pages[] inside f_mapping; o create f_inode for each file -- for this we need some mount point, so I'll create something like vdsofs, register this filesystem and mount it in initcall (or like do_basic_setup - as it's done by shmem, i.e).
Is this the idea, or I got it wrong?
And maybe the idea is to create fake vm_file for just reference counting, but do not treat/init it like file with inode, etc? So with fake file I can also check if vdso is mapped already, but I'm sure the fake file will not help Oleg with uprobes.
-- Dmitry
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