db868b4532
[ Upstream commit 9b3b353ef330e20bc2d99bf3165cc044cff26a09 ]
Commit 9d682ea6bcc7 ("vboxsf: Fix the check for the old binary
mount-arguments struct") was meant to fix a build error due to sign
mismatch in 'char' and the use of character constants, but it just moved
the error elsewhere, in that on some architectures characters and signed
and on others they are unsigned, and that's just how the C standard
works.
The proper fix is a simple "don't do that then". The code was just
being silly and odd, and it should never have cared about signed vs
unsigned characters in the first place, since what it is testing is not
four "characters", but four bytes.
And the way to compare four bytes is by using "memcmp()".
Which compilers will know to just turn into a single 32-bit compare with
a constant, as long as you don't have crazy debug options enabled.
Link: https://lore.kernel.org/lkml/20210927094123.576521-1-arnd@kernel.org/
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.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.