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d5024dc5e6
commit a75ad2fc76a2ab70817c7eed3163b66ea84ca6ac upstream.
We have a number of hwcaps for various SME subfeatures enumerated via
ID_AA64SMFR0_EL1. Currently we advertise these without cross checking
against the main SME feature, advertised in ID_AA64PFR1_EL1.SME which
means that if the two are out of sync userspace can see a confusing
situation where SME subfeatures are advertised without the base SME
hwcap. This can be readily triggered by using the arm64.nosme override
which only masks out ID_AA64PFR1_EL1.SME, and there have also been
reports of VMMs which do the same thing.
Fix this as we did previously for SVE in 064737920bdb ("arm64: Filter
out SVE hwcaps when FEAT_SVE isn't implemented") by filtering out the
SME subfeature hwcaps when FEAT_SME is not present.
Fixes: 5e64b862c4 ("arm64/sme: Basic enumeration support")
Reported-by: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250620-arm64-sme-filter-hwcaps-v1-1-02b9d3c2d8ef@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.