Once we get a glibc with 64-bit time_t, the LPSETTIMEOUT ioctl stops
working, since the command number and data structure no longer match.
To work around that, this introduces a new command number LPSETTIMEOUT_NEW
that is used whenever the modified user space evaluates the LPSETTIMEOUT
macro.
The trick we use is a bit convoluted but necessary: we cannot check for
any macros set by the C library in linux/lp.h, because this particular
header can be included before including sys/time.h. However, we can assume
that by the time that LPSETTIMEOUT is seen in the code, the definition
for 'timeval' and 'time_t' has been seen as well, so we can use the
sizeof() operator to determine whether we should use the old or the
new definition. We use the old one not only for traditional 32-bit user
space with 32-bit time_t, but also for all 64-bit architectures and x32,
which always use a 64-bit time_t, the new definition will be used only for
32-bit user space with 64-bit time_t, which also requires a newer kernel.
The compat_ioctl() handler now implements both commands, but has to
use a special case for existing x32 binaries. The native ioctl handler
now implements both command numbers on both 32-bit and 64-bit, though
the latter version use the same interpretation for both.
This is based on an earlier patch from Bamvor.
Cc: Bamvor Jian Zhang <bamv2005@gmail.com>
Link: http://www.spinics.net/lists/y2038/msg01162.html
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.
By default are files without license information under the default
license of the kernel, which is GPLV2. Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
otherwise syscall usage would not be possible.
Update the files which contain no license information with an SPDX
license identifier. The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception. SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
