linux-kernel - Re: [PATCH] uprobes/x86: allow to probe a "nop" insn with 0x66 prefix

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <871qpiqaz3.ffs@tglx>
Date:   Fri, 02 Dec 2022 12:52:16 +0100
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Oleg Nesterov <oleg@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Masami Hiramatsu <mhiramat@...nel.org>
Cc:     Denys Vlasenko <dvlasenk@...hat.com>,
        Seiji Nishikawa <snishika@...hat.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] uprobes/x86: allow to probe a "nop" insn with 0x66 prefix

On Thu, Dec 01 2022 at 15:26, Oleg Nesterov wrote:

> From: Denys Vlasenko <dvlasenk@...hat.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@...hat.com>
> Signed-off-by: Oleg Nesterov <oleg@...hat.com>

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