linux-kernel - Re: [PATCH 4/7] KVM: arm64: guest debug, add SW break point support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20141129162146.GG23653@cbox>
Date:	Sat, 29 Nov 2014 17:21:46 +0100
From:	Christoffer Dall <christoffer.dall@...aro.org>
To:	Andrew Jones <drjones@...hat.com>
Cc:	Alex Bennée <alex.bennee@...aro.org>,
	kvm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	kvmarm@...ts.cs.columbia.edu, marc.zyngier@....com,
	peter.maydell@...aro.org, agraf@...e.de,
	Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
	Russell King <linux@....linux.org.uk>,
	Jonathan Corbet <corbet@....net>,
	Gleb Natapov <gleb@...nel.org>, jan.kiszka@...mens.com,
	"open list:DOCUMENTATION" <linux-doc@...r.kernel.org>,
	Will Deacon <will.deacon@....com>,
	open list <linux-kernel@...r.kernel.org>,
	dahi@...ux.vnet.ibm.com, Catalin Marinas <catalin.marinas@....com>,
	r65777@...escale.com, pbonzini@...hat.com, bp@...e.de
Subject: Re: [PATCH 4/7] KVM: arm64: guest debug, add SW break point support

On Wed, Nov 26, 2014 at 05:07:20PM +0100, Andrew Jones wrote:
> On Tue, Nov 25, 2014 at 04:10:02PM +0000, Alex Bennée wrote:
> > This adds support for SW breakpoints inserted by userspace.
> > 
> > First we need to trap all BKPT exceptions in the hypervisor (ELS). This
> > in controlled through the MDCR_EL2 register. I've added a new field to
> > the vcpu structure to hold this value. There should be scope to
> > rationlise this with the VCPU_DEBUG_FLAGS/KVM_ARM64_DEBUG_DIRTY_SHIFT
> > manipulation in later patches.
> 
> I think we should start using the new mdcr_el2 field everywhere we plan
> to within the same series that it is introduced. Otherwise it's hard
> to tell if we need an mdcr_el2 field, or if a more generic field would
> suffice. We can always translate bits of a more generic field to
> mdcr_el2 bits when necessary, but not the reverse.
> 
Agreed, this is getting messy already with this patch.

-Christoffer
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/