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    SubjectRe: [PATCH 04/29] x86/livepatch: Validate __fentry__ location
    On Wed, 23 Feb 2022 11:57:26 +0100
    Peter Zijlstra <peterz@infradead.org> wrote:

    > --- a/kernel/trace/ftrace.c
    > +++ b/kernel/trace/ftrace.c
    > @@ -1578,7 +1578,23 @@ unsigned long ftrace_location_range(unsi
    > */
    > unsigned long ftrace_location(unsigned long ip)
    > {
    > - return ftrace_location_range(ip, ip);
    > + struct dyn_ftrace *rec;
    > + unsigned long offset;
    > + unsigned long size;
    > +
    > + rec = lookup_rec(ip, ip);
    > + if (!rec) {
    > + if (!kallsyms_lookup_size_offset(ip, &size, &offset))
    > + goto out;
    > +
    > + rec = lookup_rec(ip - offset, (ip - offset) + size);
    > + }
    > +

    Please create a new function for this. Perhaps find_ftrace_location().

    ftrace_location() is used to see if the address given is a ftrace
    nop or not. This change will make it always return true.

    -- Steve

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