Fix thread fault, on user mode, when reading variable rt_clock_base.
For the moment, clock_settime is left without system call:
we don't want to expose clock_settime without figuring out access
control
Signed-off-by: Julien D'Ascenzio <julien.dascenzio@paratronic.fr>
Previous version calculated rt_clock_base incorrectly by subtracting
clock_gettime from the specified time. Effectively the following
formula was used.
rt_clock_base := new_time - clock_gettime()
This is clearly incorrect when we consider what should happen if we
call clock_settime with the result of clock_gettime. It ought to be
approximately a no-op, but instead we end up zeroing the clock.
rt_clock_base := clock_gettime() - clock_gettime() = 0
This patch fixes clock_settime by instead using k_uptime_get to
calculate rt_clock_base, like so:
rt_clock_base := new_time - k_uptime_get()
Trying the earlier thought experiment we get:
rt_clock_base := clock_gettime() - k_uptime_get()
Using the definition of clock_gettime this expands to:
rt_clock_base := (rt_clock_base + k_uptime_get()) - k_uptime_get()
The two k_uptime_get() terms cancel out, leaving:
rt_clock_base := rt_clock_base
I.e. the no-op that we expect when calling clock_settime with
the result of clock_gettime.
Note: The bug is only observable when rt_clock_base is non-zero.
So when clock_settime is called for the first time, it will appear
to work correctly since rt_clock_base is initialized to 0.
Signed-off-by: Alexander Mihajlovic <alexander.mihajlovic@endian.se>
According to POSIX, that's the header which defines this function.
Similarly, nothing in POSIX indicates that <time.h> should have
access to struct timeval, so it's removed (it's made accessible
to <sys/time.h> via <sys/_timeval.h> introduced earlier).
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Both SDK 0.10.0-beta2 and the ARM gcc 2018q2 run into a build issue with
newlib and conflict definitions of mode_t type.
First we need to add some ifdef protection if mode_t is already defined
and set _MODE_T_DECLARED if we are the first to define it.
Secondarily, we rename include/posix/sys/types.h to
include/posix/posix_types.h so that we aren't getting a name collusion
with the system sys/types.h and that we can easily and clearily include
it (which we need to do to pull in the info from newlib).
Fixes: #12224
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Add a private variable `rt_clock_base` that can be used to determine a
real-time clock by using the `k_uptime_get` clock. Once `clock_settime`
is added, this can allow us to have a meaningful real time clock.
Signed-off-by: David Brown <david.brown@linaro.org>
Provide an implementation of gettimeofday(). This uses clock_gettime()
with the CLOCK_REALTIME parameter, which is currently unimplemented, but
will allow clients to call this function once this functionality has
been implemented.
Signed-off-by: David Brown <david.brown@linaro.org>
Use k_uptime_get() to compute both tv_sec and tv_nsec members
of timespec structure.
Fixes#8009
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Move posix layer from 'kernel' to 'lib' folder as it is not
a core kernel feature.
Fixed posix header file dependencies as part of the move and
also removed NEWLIBC related macros from posix headers.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
