[PATCH v4 0/3] Convert ppdev to y2038 safe

[Bamvor Jian Zhang]

These series of patches try to convert parport device(ppdev) to
y2038 safe, and support y2038 safe and unsafe application at the
same time. The first two version is here[1][2][3].

An y2038 safe application/kernel use 64bit time_t(aka time64_t)
to avoid 32-bit time types broken in the year 2038. Given that
some time relative struct(e.g. timeval in ppdev.c) is mainly the
offset of the real time, the old 32bit time_t in such application
is safe. We need to handle the 32bit time_t and 64bit time_t
application at the same time. My approach here is handle them as
different ioctl command for different size of timeval.

Build successful on arm64, arm and x86_64 with C=1.

Changes since v3:
1.  Remove the useless compat ioctl in fs/compat_ioctl.c for
    parport device.

Changes since v2:
1.  Fix the wrong parameter in copy_to_user.

Changes since v1:
1.  Fix the warning when build against x86_64.

[1] https://lkml.org/lkml/2015/12/9/32
[2] https://lkml.org/lkml/2015/12/17/111
[3] http://www.spinics.net/lists/y2038/msg01059.html

Bamvor Jian Zhang (3):
  ppdev: convert to y2038 safe
  ppdev: add support for compat ioctl
  fs/compat: remove useless compat ioctl for parport device

 drivers/char/ppdev.c | 87 ++++++++++++++++++++++++++++++++++++++++------------
 fs/compat_ioctl.c    | 22 -------------
 2 files changed, 67 insertions(+), 42 deletions(-)

-- 
2.1.4