2ebe81c6d8
switch_to() and flush_thread() write the task's PKRU value eagerly so the PKRU value of current is always valid in the hardware. That means there is no point in restoring PKRU on exit to user or when reactivating the task's FPU registers in the signal frame setup path. This allows to remove all the xstate buffer updates with PKRU values once the PKRU state is stored in thread struct while a task is scheduled out. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121456.303919033@linutronix.de
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.