From mboxrd@z Thu Jan  1 00:00:00 1970
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Mon, 05 Jul 2021 10:05:55 +0000
Subject: Re: [PATCH -tip v8 01/13] ia64: kprobes: Fix to pass correct trampoline address to the handler
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To: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>, Josh Poimboeuf <jpoimboe@redhat.com>, X86 ML <x86@kernel.org>, Daniel Xu <dxu@dxuuu.xyz>, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kuba@kernel.org, mingo@redhat.com, ast@kernel.org, Thomas Gleixner <tglx@linutronix.de>, Borislav Petkov <bp@alien8.de>, Peter Zijlstra <peterz@infradead.org>, kernel-team@fb.com, yhs@fb.com, linux-ia64@vger.kernel.org, Abhishek Sagar <sagar.abhishek@gmail.com>, Andrii Nakryiko <andrii.nakryiko@gmail.com>

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>