linux-kernel - Re: [PATCH v5 05/27] arm64: Use daifflag_restore after bp

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: <641119b9-3466-817d-3d6b-dd710c646b49@arm.com>
Date:   Wed, 12 Sep 2018 11:32:21 +0100
From:   James Morse <james.morse@....com>
To:     Julien Thierry <julien.thierry@....com>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        daniel.thompson@...aro.org, joel@...lfernandes.org,
        marc.zyngier@....com, mark.rutland@....com,
        christoffer.dall@....com, catalin.marinas@....com,
        will.deacon@....com
Subject: Re: [PATCH v5 05/27] arm64: Use daifflag_restore after bp_hardening

Hi Julien,

On 28/08/18 16:51, Julien Thierry wrote:
> For EL0 entries requiring bp_hardening, daif status is kept at
> DAIF_PROCCTX_NOIRQ until after hardening has been done. Then interrupts
> are enabled through local_irq_enable().
> 
> Before using local_irq_* functions, daifflags should be properly restored
> to a state where IRQs are enabled.

> Enable IRQs by restoring DAIF_PROCCTX state after bp hardening.

Is this just for symmetry, or are you going on to add something to the daifflags
state that local_irq_* functions won't change? (if so, could you allude to that
in the commit message)


Either way,

Acked-by: James Morse <james.morse@....com>