linux-kernel - Re: [PATCH] uprobes/x86: emulate push insns for uprobe on x86

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 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]

Date:   Thu, 9 Nov 2017 15:04:16 +0100
From:   Oleg Nesterov <oleg@...hat.com>
To:     Yonghong Song <yhs@...com>
Cc:     mingo@...nel.org, tglx@...utronix.de, peterz@...radead.org,
        linux-kernel@...r.kernel.org, x86@...nel.org,
        netdev@...r.kernel.org, ast@...com, kernel-team@...com
Subject: Re: [PATCH] uprobes/x86: emulate push insns for uprobe on x86

On 11/09, Oleg Nesterov wrote:
>
> And. Do you really need ->post_xol() method to emulate "push"? Why we can't
> simply execute it out-of-line if copy_to_user() fails?
>
> branch_post_xol_op() is needed because we can't execute "call" out-of-line,
> we need to restart and try again if copy_to_user() fails, but I don not
> understand why it is needed to emulate "push".

If I wasn't clear, please see the comment in branch_clear_offset().

Oleg.