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Date:   Sat, 24 Aug 2019 02:00:38 +0200 (CEST)
From:   Thomas Gleixner <tglx@linutronix.de>
To:     Andy Lutomirski <luto@amacapital.net>
cc:     Sebastian Mayr <me@sam.st>, Ingo Molnar <mingo@redhat.com>,
        Borislav Petkov <bp@alien8.de>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Dmitry Safonov <dsafonov@virtuozzo.com>,
        Oleg Nesterov <oleg@redhat.com>,
        Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Subject: Re: [PATCH] uprobes/x86: fix detection of 32-bit user mode
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On Fri, 23 Aug 2019, Andy Lutomirski wrote:
> > On Aug 23, 2019, at 4:44 PM, Thomas Gleixner <tglx@linutronix.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 ....
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