Re: [PATCH -tip v8 01/13] ia64: kprobes: Fix to pass correct trampoline address to the handler

Masami Hiramatsu
2021-07-05T10:05:55Z

On Mon, 5 Jul 2021 09:46:33 +0200
Ingo Molnar <mingo@kernel.org> wrote:

>
> * Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> > Commit e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler")
> > missed to pass the wrong trampoline address (it passes the descriptor address
> > instead of function entry address).
> > This fixes it to pass correct trampoline address to __kretprobe_trampoline_handler().
> > This also changes to use correct symbol dereference function to get the
> > function address from the kretprobe_trampoline.
> >
> > Fixes: e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler")
> > Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
>
> A better changelog:
>
> The following commit:
>
> Commit e792ff804f49 ("ia64: kprobes: Use generic kretprobe trampoline handler")
>
> Passed the wrong trampoline address to __kretprobe_trampoline_handler(): it
> passes the descriptor address instead of function entry address.
>
> Pass the right parameter.
>
> Also use correct symbol dereference function to get the function address
> from 'kretprobe_trampoline' - an IA64 special.

Thanks for rewriting! OK, I'll update it.

>
> (Although I realize that much of this goes away just a couple of patches
> later.)

Yes, but since this is a real bug. I think I should split it for backporting
to stable trees. (Oh, I also forgot to add Cc: stable. Sorry about that.)

Thank you,

--
Masami Hiramatsu <mhiramat@kernel.org>