b5d1c39f34
If we end up without a PGD or PUD entry backing the gate area, don't BUG -- just fail gracefully. It's not entirely implausible that this could happen some day on x86. It doesn't right now even with an execute-only emulated vsyscall page because the fixmap shares the PUD, but the core mm code shouldn't rely on that particular detail to avoid OOPSing. Link: http://lkml.kernel.org/r/a1d9f4efb75b9d464e59fd6af00104b21c58f6f7.1561610798.git.luto@kernel.org Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Florian Weimer <fweimer@redhat.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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.