cb968afc78
When deciding whether to invalidate FPSIMD state cached in the cpu, the backend function sve_flush_cpu_state() attempts to dereference __this_cpu_read(fpsimd_last_state). However, this is not safe: there is no guarantee that this task_struct pointer is still valid, because the task could have exited in the meantime. This means that we need another means to get the appropriate value of TIF_SVE for the associated task. This patch solves this issue by adding a cached copy of the TIF_SVE flag in fpsimd_last_state, which we can check without dereferencing the task pointer. In particular, although this patch is not a KVM fix per se, this means that this check is now done safely in the KVM world switch path (which is currently the only user of this code). Signed-off-by: Dave Martin <Dave.Martin@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.