4b9d2a731c
Use register r29 instead of register r8 to signal faults when accessing user memory. In case of faults, the fixup routine will store -EFAULT in this register. This change saves up to 752 bytes on a 32bit kernel, partly because the compiler doesn't need to save and restore the old r8 value on the stack. bloat-o-meter results for usage with r29 register: add/remove: 0/0 grow/shrink: 23/86 up/down: 228/-980 (-752) bloat-o-meter results for usage with r28 register: add/remove: 0/0 grow/shrink: 28/83 up/down: 296/-956 (-660) Signed-off-by: Helge Deller <deller@gmx.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.