mirror of
https://github.com/torvalds/linux.git
synced 2026-05-05 23:05:25 -04:00
dcd7a55941
Fine grained unix mediation in Ubuntu used ABI v7, and policy using this has propogated onto systems where fine grained unix mediation was not supported. The userspace policy compiler supports downgrading policy so the policy could be shared without changes. Unfortunately this had the side effect that policy was not updated for the none Ubuntu systems and enabling fine grained unix mediation on those systems means that a new kernel can break a system with existing policy that worked with the previous kernel. With fine grained af_unix mediation this regression can easily break the system causing boot to fail, as it affect unix socket files, non-file based unix sockets, and dbus communication. To aoid this regression move fine grained af_unix mediation behind a new abi. This means that the system's userspace and policy must be updated to support the new policy before it takes affect and dropping a new kernel on existing system will not result in a regression. The abi bump is done in such a way as existing policy can be activated on the system by changing the policy abi declaration and existing unix policy rules will apply. Policy then only needs to be incrementally updated, can even be backported to existing Ubuntu policy. Signed-off-by: John Johansen <john.johansen@canonical.com>
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 reStructuredText 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.