fbb6cda441
Introduce a new algorithm flag CRYPTO_ALG_ALLOCATES_MEMORY. If this flag is set, then the driver allocates memory in its request routine. Such drivers are not suitable for disk encryption because GFP_ATOMIC allocation can fail anytime (causing random I/O errors) and GFP_KERNEL allocation can recurse into the block layer, causing a deadlock. For now, this flag is only implemented for some algorithm types. We also assume some usage constraints for it to be meaningful, since there are lots of edge cases the crypto API allows (e.g., misaligned or fragmented scatterlists) that mean that nearly any crypto algorithm can allocate memory in some case. See the comment for details. Also add this flag to CRYPTO_ALG_INHERITED_FLAGS so that when a template is instantiated, this flag is set on the template instance if it is set on any algorithm the instance uses. Based on a patch by Mikulas Patocka <mpatocka@redhat.com> (https://lore.kernel.org/r/alpine.LRH.2.02.2006301414580.30526@file01.intranet.prod.int.rdu2.redhat.com). Signed-off-by: Eric Biggers <ebiggers@google.com> 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.