From: Will Deacon <will@kernel.org>
To: Mark Brown <broonie@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 1/3] arm64: insn: Don't assume unrecognized HINTs are NOPs
Date: Thu, 30 Apr 2020 17:08:21 +0100 [thread overview]
Message-ID: <20200430160821.GC25258@willie-the-truck> (raw)
In-Reply-To: <20200428172433.48830-2-broonie@kernel.org>
On Tue, Apr 28, 2020 at 06:24:31PM +0100, Mark Brown wrote:
> Currently the kernel assumes that any HINT which it does not explicitly
> recognise is a NOP. This is not robust as new instructions may be added
> which need special handling, including recent extensions like PAC, and
> in any case software should only be using explicit NOP instructions for
> deliberate NOPs.
Hmm, I'm not sure that using PAC as the justification makes tonnes of sense
here, since you go ahead and whitelist the PAC hints in patch 3!
Will
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next prev parent reply other threads:[~2020-04-30 16:08 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 17:24 [PATCH v2 0/3] arm64: Make NOP handling a whitelist Mark Brown
2020-04-28 17:24 ` [PATCH v2 1/3] arm64: insn: Don't assume unrecognized HINTs are NOPs Mark Brown
2020-04-30 16:08 ` Will Deacon [this message]
2020-04-28 17:24 ` [PATCH v2 2/3] arm64: insn: Add constants for PAC and BTI instruction decode Mark Brown
2020-04-30 16:07 ` Will Deacon
2020-04-30 16:45 ` Mark Brown
2020-04-28 17:24 ` [PATCH v2 3/3] arm64: insn: Report PAC and BTI instructions as NOPs Mark Brown
2020-04-30 16:09 ` Will Deacon
2020-04-30 17:16 ` Mark Brown
2020-04-30 17:20 ` Will Deacon
2020-04-30 17:36 ` Mark Brown
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