On Thu, Oct 1, 2020 at 1:59 PM Gabriel Krisman Bertazi <[email protected]> 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.
I like this quite a bit, but can you rename MM_CONTEXT_GATE_PAGE to MM_CONTEXT_HAS_VSYSCALL? --Andy
