From: David Hildenbrand <david@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Nick Desaulniers <nick.desaulniers@gmail.com>
Cc: syzbot
<bot+eb276410a47365e399ee50d68e73650cac178e0f@syzkaller.appspotmail.com>,
borntraeger@de.ibm.com, hpa@zytor.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, lstoakes@gmail.com,
mhocko@suse.com, mingo@redhat.com, rkrcmar@redhat.com,
syzkaller-bugs@googlegroups.com, tglx@linutronix.de,
x86@kernel.org
Subject: Re: BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:LINE
Date: Mon, 6 Nov 2017 17:46:22 +0100 [thread overview]
Message-ID: <a723cd0c-61fa-be97-be42-72d0cc4acb86@redhat.com> (raw)
In-Reply-To: <448b4fe1-0058-867c-e195-c77ed70718f4@redhat.com>
On 06.11.2017 17:37, Paolo Bonzini wrote:
> On 06/11/2017 17:19, David Hildenbrand wrote:
>> On 06.11.2017 17:14, Paolo Bonzini wrote:
>>> On 06/11/2017 17:01, David Hildenbrand wrote:
>>>> On 06.11.2017 16:10, Nick Desaulniers wrote:
>>>>> Does it have to be stack allocated?
>>>>
>>>> We can't use kmalloc and friends in emulate.c. We would have to
>>>> introduce new emulator callbacks.
>>>>
>>>> a) for malloc and free. hmmm.
>>>> b) for carrying out the fxrstr/fixup.
>>>>
>>>> Paolo, what do you suggest?
>>>
>>> You can use kmalloc. Any userspace user of emulate.c would have to
>>> write a wrapper. But I'm not sure it's useful... maybe the
>>> asm_safe+memcpy could be moved to a separate noinline function, so that
>>> segmented_read_std is invoked with a leaner stack.
>>
>> That's basically what we had before 9d643f63128b, however without the
>> "noinline".
>
> Indeed. I do prefer the usage of __fxstate_size though that was
> introduced by 9d643f63128b.
>
> Paolo
>
So I'll modify my patch to have that inside a static noinline function
and resend.
Thanks.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2017-11-06 16:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-31 11:34 syzbot
2017-11-06 11:51 ` David Hildenbrand
[not found] ` <CAH7mPvjcQ8esFKY7VobmRt2RcHJLApn+Sd4sigAzeSuZWSzyhg@mail.gmail.com>
2017-11-06 16:01 ` David Hildenbrand
2017-11-06 16:14 ` Paolo Bonzini
2017-11-06 16:19 ` David Hildenbrand
2017-11-06 16:37 ` Paolo Bonzini
2017-11-06 16:46 ` David Hildenbrand [this message]
2017-11-06 19:04 ` Dmitry Vyukov
2017-11-07 12:29 ` Paolo Bonzini
2017-11-07 12:44 ` Dmitry Vyukov
2018-01-26 21:11 ` Eric Biggers
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