65d1e3c415
Taking ownership of the FPU in kernel mode disables preemption, and this may result in excessive scheduling blackouts if the size of the data being processed on the FPU is unbounded. Given that taking and releasing the FPU is cheap these days on x86, we can limit the impact of this issue easily for skcipher implementations, by moving the FPU begin/end calls inside the skcipher walk processing loop. Considering that skcipher walks operate on at most one page at a time, doing so fully mitigates this issue. This also permits the skcipher walk logic to use non-atomic kmalloc() calls etc so we can change the 'atomic' bool argument in the calls to skcipher_walk_virt() to false as well. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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.