From: Juergen Gross <jgross@suse.com>
To: Jan Beulich <JBeulich@suse.com>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Lutomirski <luto@kernel.org>,
xen-devel <xen-devel@lists.xenproject.org>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3] x86-64/Xen: fix stack switching
Date: Wed, 16 Jan 2019 12:51:20 +0100 [thread overview]
Message-ID: <87b0cc15-0e62-db9e-391d-77b42a2626b1@suse.com> (raw)
In-Reply-To: <5C3E1128020000780020DFAD@suse.com>
On 15/01/2019 17:58, Jan Beulich wrote:
> While in the native case entry into the kernel happens on the trampoline
> stack, PV Xen kernels get entered with the current thread stack right
> away. Hence source and destination stacks are identical in that case,
> and special care is needed.
>
> Other than in sync_regs() the copying done on the INT80 path isn't
> NMI / #MC safe, as either of these events occurring in the middle of the
> stack copying would clobber data on the (source) stack.
>
> I'm not altering the similar code in interrupt_entry() and nmi(), as
> those code paths are unreachable afaict when running PV Xen guests.
>
> Fixes: 7f2590a110b837af5679d08fc25c6227c5a8c497
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Cc: stable@kernel.org
Reviewed-by: Juergen Gross <jgross@suse.com>
Juergen
next parent reply other threads:[~2019-01-16 11:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5AF03EBD02000078001C1303@suse.com>
[not found] ` <5AF03EBD02000000000F91D6@suse.com>
[not found] ` <5AF03EBD02000078001FE590@suse.com>
[not found] ` <5C3E1128020000780020DFAD@suse.com>
2019-01-16 11:51 ` Juergen Gross [this message]
2018-05-07 11:55 [PATCH] " Jan Beulich
[not found] ` <5AF03EBD02000000000F91D6@prv1-mh.provo.novell.com>
[not found] ` <5AF03EBD02000078001FE590@prv1-mh.provo.novell.com>
2019-01-15 16:58 ` [PATCH v3] " Jan Beulich
2019-01-17 0:09 ` Andy Lutomirski
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