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To:     Oleg Nesterov <oleg@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Masami Hiramatsu <mhiramat@kernel.org>
Cc:     Denys Vlasenko <dvlasenk@redhat.com>,
        Seiji Nishikawa <snishika@redhat.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] uprobes/x86: allow to probe a "nop" insn with 0x66 prefix
In-Reply-To: <20221201142644.GA27185@redhat.com>
References: <20221201142644.GA27185@redhat.com>
Date:   Fri, 02 Dec 2022 12:52:16 +0100
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On Thu, Dec 01 2022 at 15:26, Oleg Nesterov wrote:

> From: Denys Vlasenko <dvlasenk@redhat.com>
>
> Intel icc -hotpatch inserts 2-byte "0x66 0x90" NOP at the start of each
> function to reserve extra space for hot-patching, and currently it is not
> possible to probe these functions because branch_setup_xol_ops() wrongly
> nacks NOP with REP prefix.
>
> Fixes: 250bbd12c2fe ("uprobes/x86: Refuse to attach uprobe to "word-sized" branch insns")
> Reported-by: Seiji Nishikawa <snishika@redhat.com>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

The SOB chain is invalid as it lacks the author's signoff.