linux-kernel - Re: [PATCH] uprobes/x86: fix detection of 32-bit user mode

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: <alpine.DEB.2.21.1908240200070.1939@nanos.tec.linutronix.de>
Date:   Sat, 24 Aug 2019 02:00:38 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Andy Lutomirski <luto@...capital.net>
cc:     Sebastian Mayr <me@....st>, Ingo Molnar <mingo@...hat.com>,
        Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        LKML <linux-kernel@...r.kernel.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Dmitry Safonov <dsafonov@...tuozzo.com>,
        Oleg Nesterov <oleg@...hat.com>,
        Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
Subject: Re: [PATCH] uprobes/x86: fix detection of 32-bit user mode

On Fri, 23 Aug 2019, Andy Lutomirski wrote:
> > On Aug 23, 2019, at 4:44 PM, Thomas Gleixner <tglx@...utronix.de> wrote:
> > 
> >> On Sat, 24 Aug 2019, Thomas Gleixner wrote:
> >>> On Sun, 28 Jul 2019, Sebastian Mayr wrote:
> >>> 
> >>> -static inline int sizeof_long(void)
> >>> +static inline int sizeof_long(struct pt_regs *regs)
> >>> {
> >>> -    return in_ia32_syscall() ? 4 : 8;
> >> 
> >>  This wants a comment.
> >> 
> >>> +    return user_64bit_mode(regs) ? 8 : 4;
> > 
> > The more simpler one liner is to check
> > 
> >    test_thread_flag(TIF_IA32)
> 
> I still want to finish killing TIF_IA32 some day.  Let’s please not add new users.

Well, yes and no. This needs to be backported ....