Messages in this thread | | | Date | Tue, 14 Apr 2015 17:28:46 -0700 | From | Andy Lutomirski <> | Subject | Re: x86_64: Question about fixmaps |
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On 04/14/2015 06:16 AM, Alexander Kuleshov wrote: > Hello All, > > I'm reading x86_64 source code and trying to understand where are > fixmaps space in the virtual memory space. If I understand correctly > (but i'm really not sure about it), fixmap space is after vsyscall > space. As Documentation/x86/x86_64/mm.txt says vsyscall virtual space > is: > > ffffffffff600000 - ffffffffffdfffff (=8 MB) vsyscalls > > With 'earlyprintk' i got FIXADDR_START and FIXADDR_TOP and they are: > > FIXADDR_START - 0xffffffffff779000L > FIXADDR_TOP - 0xffffffffff7ff000L > > with these addressess FIXADDR_START/FIXADDR_TOP overlap vsyscalls > area. Is it correct case that fixmaps are in vsyscal virtual memory > space or I'm wrong somewhere?
It's the other way around. vsyscalls are in the fixmap. I should fix the docs.
--Andy
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