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    SubjectRe: [RFC][PATCH 00/24] x86/pti: Defer CR3 switch to C code
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    On 11/9/20 6:44 AM, Alexandre Chartre wrote:
    > - map more syscall, interrupt and exception entry code into the user
    > page-table (map all noinstr code);

    This seems like the thing we'd want to tag explicitly rather than make
    it implicit with 'noinstr' code. Worst-case, shouldn't this be:

    #define __entry_func noinstr

    or something?

    I'd also like to see a lot more discussion about what the rules are for
    the C code and the compiler. We can't, for instance, do a normal
    printk() in this entry functions. Should we stick them in a special
    section and have objtool look for suspect patterns or references?

    I'm most worried about things like this:

    if (something_weird)
    pr_warn("this will oops the kernel\n");

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