linux/fs/vboxsf
Linus Torvalds db868b4532 vboxfs: fix broken legacy mount signature checking
[ Upstream commit 9b3b353ef3 ]

Commit 9d682ea6bc ("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>
2021-10-17 10:43:33 +02:00
..
dir.c vboxsf: Add support for the atomic_open directory-inode op 2021-08-18 08:59:18 +02:00
file.c vboxsf: Add vboxsf_[create|release]_sf_handle() helpers 2021-08-18 08:59:17 +02:00
Kconfig
Makefile
shfl_hostintf.h
super.c vboxfs: fix broken legacy mount signature checking 2021-10-17 10:43:33 +02:00
utils.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
vboxsf_wrappers.c
vfsmod.h vboxsf: Add vboxsf_[create|release]_sf_handle() helpers 2021-08-18 08:59:17 +02:00