Le 16/02/2022 à 14:13, Arnd Bergmann a écrit :
From: Arnd Bergmann <arnd@xxxxxxxx>
Christoph Hellwig and a few others spent a huge effort on removing
set_fs() from most of the important architectures, but about half the
other architectures were never completed even though most of them don't
actually use set_fs() at all.
I did a patch for microblaze at some point, which turned out to be fairly
generic, and now ported it to most other architectures, using new generic
implementations of access_ok() and __{get,put}_kernel_nocheck().
Three architectures (sparc64, ia64, and sh) needed some extra work,
which I also completed.
The final series contains extra cleanup changes that touch all
architectures. Please review and test these, so we can merge them
for v5.18.
As a further cleanup, have you thought about making a generic version of
clear_user() ? On almost all architectures, clear_user() does an
access_ok() then calls __clear_user() or similar.
Maybe also the same with put_user() and get_user() ? After all it is
just access_ok() followed by __put_user() or __get_user() ? It seems
more tricky though, as some architectures seems to have less trivial
stuff there.
I also see all architectures have a prototype for strncpy_from_user()
and strnlen_user(). Could be a common prototype instead when we have
GENERIC_STRNCPY_FROM_USER / GENERIC_STRNLEN_USER
And we have also
user_access_begin()/user_read_access_begin()/user_write_access_begin()
which call access_ok() then do the real work. Could be made generic with
call to some arch specific __user_access_begin() and friends after the
access_ok() and eventually the might_fault().
Christophe
