mainlining shenanigans
dbaba47085
Current initialization flow of split lock detection has following issues: 1. It assumes the initial value of MSR_TEST_CTRL.SPLIT_LOCK_DETECT to be zero. However, it's possible that BIOS/firmware has set it. 2. X86_FEATURE_SPLIT_LOCK_DETECT flag is unconditionally set even if there is a virtualization flaw that FMS indicates the existence while it's actually not supported. Rework the initialization flow to solve above issues. In detail, explicitly clear and set split_lock_detect bit to verify MSR_TEST_CTRL can be accessed, and rdmsr after wrmsr to ensure bit is cleared/set successfully. X86_FEATURE_SPLIT_LOCK_DETECT flag is set only when the feature does exist and the feature is not disabled with kernel param "split_lock_detect=off" On each processor, explicitly updating the SPLIT_LOCK_DETECT bit based on sld_sate in split_lock_init() since BIOS/firmware may touch it. Originally-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200325030924.132881-2-xiaoyao.li@intel.com |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
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.