Messages in this thread | | | Date | Thu, 18 Jun 2015 23:13:18 +0200 | From | Ingo Molnar <> | Subject | Re: [RFC] Rename various 'IA32' uses in arch/x86/ code |
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* Brian Gerst <brgerst@gmail.com> wrote:
> >> The original one wasn't really a misnomer, as it referred to the ia32 system > >> calls specifically, but this works too. > > > > It was a misnomer, because what are the 'ia32 system calls'? We have no Intel > > specific system calls! > > > > The term 'IA32' (Intel Architecture 32-bit) is a misnomer in many existing > > arch/x86/ symbol, function and file names, and most of them should be renamed. > > > > Some common examples, with a suggested rename target: > > > > stack_frame_ia32 -> stack_frame_compat > > IA32_RT_SIGFRAME_sigcontext -> COMPAT_RT_SIGFRAME_sigcontext > > sigcontext_ia32 -> sigcontext_compat > > user_i387_ia32_struct -> user_i387_compat_struct > > TIF_IA32 -> TIF_COMPAT > > > > and here a few 'ia32' misnomers that should be addressed not via simple renames, > > but via transformations to existing compat facilities: > > > > CONFIG_IA32_EMULATION -> partly eliminate, partly covert to CONFIG_COMPAT use > > I think we still want a symbol for code that is exclusive to 32-bit > compatibility (like entry and signal code) to keep it separate from X32 which > also wants CONFIG_COMPAT. If I get time this weekend I'll get the patchset to > do the separation updated to the tip branch.
Ok, so your goal is to allow the x32 ABI, but not 32-bit user-space?
I suppose that makes some sense, it might be a valid 'attack surface reduction' technique, while still allowing the x32 ABI.
But I'm not sure we should bother and complicate things: 32-bit compat isn't going away anytime soon, and most of CONFIG_COMPAT is needed for x32.
So maybe we could introduce CONFIG_X86_32_ABI=y or so, which would cover just the 32-bit entry code and the signal frame compatibility layer?
Thanks,
Ingo
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