From: "Andy Lutomirski" <luto@kernel.org>
To: "Peter Zijlstra (Intel)" <peterz@infradead.org>,
"Linus Torvalds" <torvalds@linux-foundation.org>
Cc: "Ondrej Zary" <linux@zary.sk>,
"Thomas Gleixner" <tglx@linutronix.de>,
"the arch/x86 maintainers" <x86@kernel.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86/iopl: Fake iopl(3) CLI/STI usage
Date: Tue, 21 Sep 2021 14:01:40 -0700 [thread overview]
Message-ID: <01288fc6-4525-48a5-8ab5-0c617fdbcfc9@www.fastmail.com> (raw)
In-Reply-To: <YUWPuPyBxR9OVtXS@hirez.programming.kicks-ass.net>
On Sat, Sep 18, 2021, at 12:05 AM, Peter Zijlstra wrote:
> On Fri, Sep 17, 2021 at 03:24:51PM -0700, Linus Torvalds wrote:
>> On Fri, Sep 17, 2021 at 3:23 PM Linus Torvalds
>> <torvalds@linux-foundation.org> wrote:
>> >
>> > I think the proper thing to do is perhaps something like
>>
>> The alternative is to just ignore cs_abse entirely, and just use
>> "regs->ip", which makes this all even easier.
>>
>> If somebody uses a code segment _and_ cli/sti, maybe they should just
>> get the SIGSEGV?
>
> I did a hatched job on fixup_ump_exception() which is why it looks like
> it does, that said...
>
> our case at hand mmap()'s BIOS code from /dev/mem and executes that, I
> don't think it does an LDT segment but it would be entirely in line with
> the level of hack we're looking at.
>
> Let me frob at this after breakfast and see if I can make it better.
The patch seems fine, but I have to ask: is this really worth fixing?
I suppose the log message could check if the computer comes from HP(E) and gently that the owner switch vendors.
next prev parent reply other threads:[~2021-09-21 21:02 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-15 12:23 IOPL emulation breaks hpasmd (hp-health) needed by HP DL380 G4 servers Ondrej Zary
2021-09-16 17:09 ` Thomas Gleixner
2021-09-16 20:27 ` Ondrej Zary
2021-09-16 21:05 ` Peter Zijlstra
2021-09-17 8:11 ` Ondrej Zary
2021-09-17 9:20 ` [PATCH] x86/iopl: Fake iopl(3) CLI/STI usage Peter Zijlstra
2021-09-17 10:29 ` Ondrej Zary
2021-09-17 11:54 ` Peter Zijlstra
2021-09-17 12:33 ` Thomas Gleixner
2021-09-17 12:54 ` Ondrej Zary
2021-09-17 10:40 ` Thomas Gleixner
2021-09-17 22:23 ` Linus Torvalds
2021-09-17 22:24 ` Linus Torvalds
2021-09-18 7:05 ` Peter Zijlstra
2021-09-18 9:06 ` Peter Zijlstra
2021-09-18 15:53 ` Ondrej Zary
2021-09-18 16:35 ` Linus Torvalds
2021-09-21 7:28 ` [tip: x86/core] " tip-bot2 for Peter Zijlstra
2021-09-21 11:09 ` Ondrej Zary
2021-09-21 12:00 ` Peter Zijlstra
2021-09-21 17:31 ` Ondrej Zary
2021-09-21 12:41 ` tip-bot2 for Peter Zijlstra
2021-09-21 21:01 ` Andy Lutomirski [this message]
2021-09-16 21:25 ` IOPL emulation breaks hpasmd (hp-health) needed by HP DL380 G4 servers Thomas Gleixner
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