a8936569a0
BPF_REG_5, BPF_REG_AX and TMP_REG are mapped on non volatile registers because there are not enough volatile registers, but they don't need to be preserved on function calls. So when some volatile registers become available, those registers can always be reallocated regardless of whether SEEN_FUNC is set or not. Suggested-by: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b04c246874b716911139c04bc004b3b14eed07ef.1641817763.git.christophe.leroy@csgroup.eu
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.