z_set_thread_return_value is part of the core kernel -> arch
interface and has been renamed to z_arch_thread_return_value_set.
z_set_thread_return_value_with_data renamed to
z_thread_return_value_set_with_data for consistency.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The semi-automated API changes weren't checkpatch aware. Fix up
whitespace warnings that snuck into the previous patches. Really this
should be squashed, but that's somewhat difficult given the structure
of the series.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
System call arguments, at the arch layer, are single words. So
passing wider values requires splitting them into two registers at
call time. This gets even more complicated for values (e.g
k_timeout_t) that may have different sizes depending on configuration.
This patch adds a feature to gen_syscalls.py to detect functions with
wide arguments and automatically generates code to split/unsplit them.
Unfortunately the current scheme of Z_SYSCALL_DECLARE_* macros won't
work with functions like this, because for N arguments (our current
maximum N is 10) there are 2^N possible configurations of argument
widths. So this generates the complete functions for each handler and
wrapper, effectively doing in python what was originally done in the
preprocessor.
Another complexity is that traditional the z_hdlr_*() function for a
system call has taken the raw list of word arguments, which does not
work when some of those arguments must be 64 bit types. So instead of
using a single Z_SYSCALL_HANDLER macro, this splits the job of
z_hdlr_*() into two steps: An automatically-generated unmarshalling
function, z_mrsh_*(), which then calls a user-supplied verification
function z_vrfy_*(). The verification function is typesafe, and is a
simple C function with exactly the same argument and return signature
as the syscall impl function. It is also not responsible for
validating the pointers to the extra parameter array or a wide return
value, that code gets automatically generated.
This commit includes new vrfy/msrh handling for all syscalls invoked
during CI runs. Future commits will port the less testable code.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
There's no need for a system call for this; futexes live in
user memory and the initialization bit is ignored.
It's sufficient to just do an atomic_set().
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
A k_futex is a lightweight mutual exclusion primitive designed
to minimize kernel involvement. Uncontended operation relies
only on atomic access to shared memory. k_futex structure lives
in application memory. And when using futexes, the majority of
the synchronization operations are performed in user mode. A
user-mode thread employs the futex wait system call only when
it is likely that the program has to block for a longer time
until the condition becomes true. When the condition comes true,
futex wake operation will be used to wake up one or more threads
waiting on that futex.
This patch implements two futex operations: k_futex_wait and
k_futex_wake. For k_futex_wait, the comparison with the expected
value, and starting to sleep are performed atomically to prevent
lost wake-ups. If different context changed futex's value after
the calling use-mode thread decided to block himself based on
the old value, the comparison will help observing the value
change and will not start to sleep. And for k_futex_wake, it
will wake at most num_waiters of the waiters that are sleeping
on that futex. But no guarantees are made on which threads are
woken, that means scheduling priority is not taken into
consideration.
Fixes: #14493.
Signed-off-by: Wentong Wu <wentong.wu@intel.com>
Andrew Boie