mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-01 04:53:09 -04:00
dc438db582
Kernel images that are large in comparison to the range of a direct branch may fail to work as expected with ftrace, as patching a direct branch to one of the core ftrace routines may not be possible from the .init.text section, if it is emitted too far away from the normal .text section. This is more likely to affect Thumb2 builds, given that its range is only -/+ 16 MiB (as opposed to ARM which has -/+ 32 MiB), but may occur in either ISA. To work around this, add a couple of trampolines to .init.text and swap these in when the ftrace patching code is operating on callers in .init.text. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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.