Messages in this thread | | | Subject | Re: [PATCH 6/6] Add 32 bit VDSO support for 32 and 64 bit kernels | From | Stefani Seibold <> | Date | Tue, 18 Dec 2012 17:52:38 +0100 |
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Am Dienstag, den 18.12.2012, 08:17 -0800 schrieb H. Peter Anvin: > On 12/18/2012 01:40 AM, stefani@seibold.net wrote: > > From: Stefani Seibold <stefani@seibold.net> > > > > This patch adds support for 32 bit VDSO. > > > > For 32 bit programs running on a 32 bit kernel, the same mechanism is > > used as for 64 bit programs running on a 64 bit kernel. > > > > For 32 bit programs running under a 64 bit IA32_EMULATION, it is a > > little bit more tricky. In this case the VVAR and HPET will be mapped > > into the 32 bit address space, by cutting of the upper 32 bit. So the > > address for this will not changed in the view of the 32 bit VDSO. The > > HPET will be mapped in this case at 0xff5fe000 and the VVAR at 0xff5ff000. > > > > The transformation between the in 64 bit kernel representation and the 32 bit > > abi will be also provided. > > > > So we have one VDSO Source for all. > > > > You seem to once again have disregarded the request to make the vvar and > hpet part of the vdso address space proper. If this is not possible or > highly impractical, please extend a technical motivation why that is so, > rather than simply ignoring it. >
Pardon, i never disregarded nor i have agreed that this is going to be a part of the VDSO. I currently have also no idea how to do this and i see no need at the moment to do this revamp. The 64 bit VDSO lives since more than 6 years with this kind of implementation.
You asked me to do the VDSO 32 bit stuff for the IA32_EMULATION, before it is ready for inclusion into the kernel. Thats exactly what i did. I spend the whole weekend of my spare time to do this implementation. Now we have them all.
The patch works perfectly, all issues are solved:
- Calling conventions - ABI transformations - System call gateway for X86 32 bit - Mapping of the FIXMAP and HPET into the lower 32 bit address space for IA32_EMULATION - Support for 32 bit programs in 32 kernel and 64 bit kernel - One VDSO source for all
If you prefer an other solutions, its okay. There are many ways to code things. But for now i think it is a good step ahead. That is what i currently can provide.
- Stefani
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