| From | Andy Lutomirski <> | Date | Wed, 7 Oct 2020 17:07:37 -0700 | Subject | Re: [PATCH v3 09/10] x86: Convert mmu context ia32_compat into a proper flags field |
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On Sat, Oct 3, 2020 at 8:26 PM Gabriel Krisman Bertazi <krisman@collabora.com> wrote: > > The ia32_compat attribute is a weird thing. It mirrors TIF_IA32 and > TIF_X32 and is used only in two very unrelated places: (1) to decide if > the vsyscall page is accessible (2) for uprobes to find whether the > patched instruction is 32 or 64 bit. In preparation to remove the TI > flags, we want new values for ia32_compat, but given its odd semantics, > I'd rather make it a real flags field that configures these specific > behaviours. So, set_personality_x64 can ask for the vsyscall page, > which is not available in x32/ia32 and set_personality_ia32 can > configure the uprobe code as needed. > > uprobe cannot rely on other methods like user_64bit_mode() to decide how > to patch, so it needs some specific flag like this.
Acked-by: Andy Lutomirski<luto@kernel.org>
There are still issues with vsyscall control, but they were pre-existing and I'll try to get them fixed up.
--Andy
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