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    SubjectRe: [PATCH 5/7] ftrace: Store direct called addresses in their ops
    On Sun, Mar 19, 2023 at 7:55 PM Jiri Olsa <olsajiri@gmail.com> wrote:
    >
    > On Sun, Mar 19, 2023 at 01:54:43PM -0400, Steven Rostedt wrote:
    > > On Sun, 19 Mar 2023 16:29:22 +0100
    > > Jiri Olsa <olsajiri@gmail.com> wrote:
    > >
    > > > > +++ b/kernel/trace/ftrace.c
    > > > > @@ -2582,9 +2582,8 @@ ftrace_add_rec_direct(unsigned long ip, unsigned long addr,
    > > > > static void call_direct_funcs(unsigned long ip, unsigned long pip,
    > > > > struct ftrace_ops *ops, struct ftrace_regs *fregs)
    > > > > {
    > > > > - unsigned long addr;
    > > > > + unsigned long addr = ops->direct_call;
    > > >
    > > > nice, should it be read with READ_ONCE ?
    > >
    > > Is there a "read tearing" too?
    >
    > don't know, saw the comment in __modify_ftrace_direct and got curious
    > why it's not in here.. feel free to ignore, I'll look it up
    >
    > jirka

    Mhh, that's a good question. Based on my current understanding, it
    seems that it should have a READ_ONCE, indeed. However, I'd like Mark
    to confirm/deny this. :)

    If this should be a READ_ONCE, I can send a v2 series with this fixed.

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