From: Greg KH <gregkh@linuxfoundation.org>
To: Alexander Popov <alex.popov@linux.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Radim Krcmar <rkrcmar@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Nadav Amit <nadav.amit@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
Stefan Hajnoczi <stefanha@redhat.com>,
H Peter Anvin <hpa@zytor.com>,
x86@kernel.org, kvm@vger.kernel.org,
kernel-hardening@lists.openwall.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] KVM: x86: Fix single-step debugging
Date: Mon, 21 Jan 2019 15:24:27 +0100 [thread overview]
Message-ID: <20190121142427.GA26671@kroah.com> (raw)
In-Reply-To: <1548074920-10651-1-git-send-email-alex.popov@linux.com>
On Mon, Jan 21, 2019 at 03:48:40PM +0300, Alexander Popov wrote:
> The single-step debugging of KVM guests on x86 is broken: if we run
> gdb 'stepi' command at the breakpoint when the guest interrupts are
> enabled, RIP always jumps to native_apic_mem_write(). Then other
> nasty effects follow.
>
> Long investigation showed that on Jun 7, 2017 the
> commit c8401dda2f0a00cd25c0 ("KVM: x86: fix singlestepping over syscall")
> introduced the kvm_run.debug corruption: kvm_vcpu_do_singlestep() can
> be called without X86_EFLAGS_TF set.
>
> Let's fix it. Please consider that for -stable.
>
> Signed-off-by: Alexander Popov <alex.popov@linux.com>
> ---
> arch/x86/kvm/x86.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
<formletter>
This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.
</formletter>
next prev parent reply other threads:[~2019-01-21 14:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 12:48 [PATCH v2] KVM: x86: Fix single-step debugging Alexander Popov
2019-01-21 14:24 ` Greg KH [this message]
2019-01-25 17:38 ` Paolo Bonzini
2019-01-24 8:41 ` Alexander Popov
2019-01-25 17:52 ` Paolo Bonzini
2019-02-05 22:55 ` Jim Mattson
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