There was no good reason to have these rather large functions in a
header. Put them into sys_clock.c for now, pending rework to the
system.
Now the API is clearly visible in a small header.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The tickless driver had a bunch of "hairy" APIs which forced the timer
drivers to do needless low-level accounting for the benefit of the
kernel, all of which then proceeded to implement them via cut and
paste. Specifically the "program_time" calls forced the driver to
expose to the kernel exactly when the next interrupt was due and how
much time had elapsed, in a parallel API to the existing "what time is
it" and "announce a tick" interrupts that carry the same information.
Remove these from the kernel, replacing them with synthesized logic
written in terms of the simpler APIs.
In some cases there will be a performance impact due to the use of the
64 bit uptime call, but that will go away soon.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The existing API had two almost identical functions: _set_time() and
_timer_idle_enter(). Both simply instruct the timer driver to set the
next timer interrupt expiration appropriately so that the call to
z_clock_announce() will be made at the requested number of ticks. On
most/all hardware, these should be implementable identically.
Unfortunately because they are specified differently, existing drivers
have implemented them in parallel.
Specify a new, unified, z_clock_set_timeout(). Document it clearly
for implementors. And provide a shim layer for legacy drivers that
will continue to use the old functions.
Note that this patch fixes an existing bug found by inspection: the
old call to _set_time() out of z_clock_announce() failed to test for
the "wait forever" case in the situation where clock_always_on is
true, meaning that a system that reached this point and then never set
another timeout would freeze its uptime clock incorrectly.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The builtin function __builtin_umul_overflow returns a boolean and
should not checked as an integer.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
According C99 the first 31 characters of an identifier must be unique.
Shortening the namespace of the generated objects to achieve it.
C99 - 5.2.4.1
MISRA-C rule 5.1
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Change APIs that essentially return a boolean expression - 0 for
false and 1 for true - to return a bool.
MISRA-C rule 14.4
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Added k_thread_name_set() and enable thread name setting when declaring
static threads. This is enabled only when THREAD_MONITOR is used. System
threads get a name by default.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Add ifdef guard to the z_reset_timeslice() to fix compilation
errors when CONFIG_TIMESLICING is disabled.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
MISRA C requires that every controlling expression of and if or while
statement have a boolean type.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Rename _DEVICE_STRUCT_SIZE to _DEVICE_STRUCT_SIZEOF. This causes it to
be picked by the script 'gen_offset_header.py' and inserted into the
header file 'include/generated/offsets.h'.
Renaming from x_SIZE to x_SIZEOF will align it's name with the other
symbols that denote a sctruct's size, like K_THREAD_SIZEOF.
Furthermore, it will allow the symbol to be accessed through a header
file define, instead of only as an extern symbol. This is more
flexible, and more aligned with the other symbols in offsets.
Finally, if we are able to move all of offsets.c symbols into the
offsets.h header file we be able to remove offsets.o from the link and
thereby simplify the linking process.
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
Any word started with underscore followed by and uppercase letter or a
second underscore is a reserved word according with C99.
With have *many* violations on Zephyr's code, this commit is tackling
only the violations caused by headers guards. It also takes the
opportunity to normalize them using the filename in uppercase and
replacing dot with underscore. e.g file.h -> FILE_H
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
__swap function was returning -EAGAIN in some case, though its return
value was declared as unsigned int.
This commit changes this function to return int since it can return a
negative value and its return was already been propagate as int.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
When adding a new runnable thread in tickless mode, we need to detect
whether it will timeslice with the running thread and reset the timer,
otherwise it won't get any CPU time until the next interrupt fires at
some indeterminate time in the future.
This fixes the specific bug discussed in #7193, but the broader
problem of tickless and timeslicing interacting badly remains. The
code as it exists needs some rework to avoid all the #ifdef mess.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
When adding a new runnable thread in tickless mode, we need to detect
whether it will timeslice with the runnable thread and reset the
timer, otherwise it won't get any CPU time until the next interrupt
fires at some indeterminate time in the future.
This fixes the specific bug discussed in #7193, but the broader
problem of tickless and timeslicing interacting badly remains. The
code as it exists needs some rework to avoid all the #ifdef mess.
Note that the patch also moves _ready_thread() from a ksched.h inline
to sched.c.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This fixes#8669, and is distressingly subtle for a one-line patch:
The list iteration code in _handle_expired_timeouts() would remove the
timeout from our (temporary -- the dlist header is on the stack of our
calling function) list of expired timeouts before invoking the
handler. But sys_dlist_remove() only fixes up the containing list
pointers, leaving garbage in the node. If the action of that handler
is to re-add the timeout (which is very common!) then that will then
try to remove it AGAIN from the same list.
Even then, the common case is that the expired list contains only one
item, so the result is a perfectly valid empty list that affects
nothing. But if you have more than one, you get a corrupt cycle in
the iteration list and things get weird.
As it happens, there's no value in trying to remove this timeout from
the temporary list at all. Just iterate over it naturally.
Really, this design is fragile: we shouldn't be reusing the list nodes
in struct _timeout for this purpose and should figure out some other
mechanism. But this fix should be good for now.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Move to more generic tracing hooks that can be implemented in different
ways and do not interfere with the kernel.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Define generic interface and hooks for tracing to replace
kernel_event_logger and existing tracing facilities with something more
common.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This patch provides support needed to get timing related
information from xtensa based SOC.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
Bitwise operators should be used only with unsigned integer operands
because the result os bitwise operations on signed integers are
implementation-defined.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
There exist two symbols that became equivalent when PR #9383 was
merged; _SYSCALL_LIMIT and K_SYSCALL_LIMIT. This patch deprecates the
redundant _SYSCALL_LIMIT symbol.
_SYSCALL_LIMIT was initally introduced because before PR #9383 was
merged K_SYSCALL_LIMIT was an enum, which couldn't be included into
assembly files. PR #9383 converted it into a define, which can be
included into assembly files, making _SYSCALL_LIMIT redundant.
Likewise for _SYSCALL_BAD.
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
We now have functions for handling all the details of copying
data to/from user mode, including C strings and copying data
into resource pool allocations.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Zephyr 1.12 removed the old scheduler and replaced it with the choice
of a "dumb" list or a balanced tree. But the old multi-queue
algorithm is still useful in the space between these two (applications
with large-ish numbers of runnable threads, but that don't need fancy
features like EDF or SMP affinity). So add it as a
CONFIG_SCHED_MULTIQ option.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Make these "choice" items instead of a single boolean that implies the
element unset.
Also renames WAITQ_FAST to WAITQ_SCALABLE, as the rbtree is really
only "fast" for large queue sizes (it's constant factor overhead is
bigger than a list's!)
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The _THREAD_POLLING bit in thread_state was never actually a
legitimate thread "state". It is a clever synchronization trick
introduced to allow the thread to release the irq_lock while looping
over the input event array without dropping events.
Instead, make that flag a word in the "poller" struct that lives on
the stack of the thread calling k_poll. The disadvantage is the 4
bytes of thread space needed. Advantages:
+ Cleaner API, it's now internal to poll instead of being globally
visible.
+ The thread_state bit space is just one byte, and was almost full
already.
+ Smaller code to write/test a full word and not a bitfield
+ Words are atomic, so no need for one of irq lock/unlock pairs.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The original implementation of CONFIG_THREAD_MONITOR would
try to leverage a thread's initial stack layout to provide
the entry function with arguments for any given thread.
This is problematic:
- Some arches do not have a initial stack layout suitable for
this
- Some arches never enabled this at all (riscv32, nios2)
- Some arches did not enable this properly
- Dropping to user mode would erase or provide incorrect
information.
Just spend a few extra bytes to store this stuff directly
in the k_thread struct and get rid of all the arch-specific
code for this.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Recent changes post-scheduler-rewrite broke scheduling on SMP:
The "preempt_ok" feature added to isolate preemption points wasn't
honored in SMP mode. Fix this by adding a "swap_ok" field to the CPU
record (not the thread) which is set at the same time out of
update_cache().
The "queued" flag wasn't being maintained correctly when swapping away
from _current (it was added back to the queue, but the flag wasn't
set).
Abstract out a "should_preempt()" predicate so SMP and uniprocessor
paths share the same logic, which is distressingly subtle.
There were two places where _Swap() was predicated on
_get_next_ready_thread() != _current. That's no longer a benign
optimization in SMP, where the former function REMOVES the next thread
from the queue. Just call _Swap() directly in SMP, which has a
unified C implementation that does this test already. Don't change
other architectures in case it exposes bugs with _Swap() switching
back to the same thread (it should work, I just don't want to break
anything).
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
We generalize querying the entropy driver directly with
a new internal API, which is now used by CONFIG_STACK_RANDOM
and stack canary initialization.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Very simple implementation of deadline scheduling. Works by storing a
single word in each thread containing a deadline, setting it (as a
delta from "now") via a single new API call, and using it as extra
input to the existing thread priority comparison function when
priorities are equal.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This replaces the existing scheduler (but not priority handling)
implementation with a somewhat simpler one. Behavior as to thread
selection does not change. New features:
+ Unifies SMP and uniprocessing selection code (with the sole
exception of the "cache" trick not being possible in SMP).
+ The old static multi-queue implementation is gone and has been
replaced with a build-time choice of either a "dumb" list
implementation (faster and significantly smaller for apps with only
a few threads) or a balanced tree queue which scales well to
arbitrary numbers of threads and priority levels. This is
controlled via the CONFIG_SCHED_DUMB kconfig variable.
+ The balanced tree implementation is usable symmetrically for the
wait_q abstraction, fixing a scalability glitch Zephyr had when many
threads were waiting on a single object. This can be selected via
CONFIG_WAITQ_FAST.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The SMP testing missed the case where _Swap() decides to return back
into the _current. Obviously there is no valid switch handle for the
running thread into which we can restore, and everything blows up.
(What happened is that the new scheduler code opened up a spot where
k_thread_priority_set() does a _reschedule() unconditionally and
doens't check to see whether or not it's needed like the old code).
But that isn't incorrect! It's entirely possible that _Swap() may
find that no thread is runnable except _current (due, for example, to
another CPU racing the other thread you expected off to sleep or
something). Don't blow up, check and return a noop.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
There were multiple spots where code was using the _wait_q_t
abstraction as a synonym for a dlist and doing direct list management
on them with the dlist APIs. Refactor _wait_q_t into a proper opaque
struct (not a typedef for sys_dlist_t) and write a simple wrapper API
for the existing usages. Now replacement of wait_q with a different
data structure is much cleaner.
Note that there were some SYS_DLIST_FOR_EACH_SAFE loops in mailbox.c
that got replaced by the normal/non-safe macro. While these loops do
mutate the list in the code body, they always do an early return in
those circumstances instead of returning into the macro'd for() loop,
so the _SAFE usage was needless.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Refactoring. Mempool wants to unpend all threads at once. It's
cleaner to do this in the scheduler instead of the IPC code.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The various macros to do checks in system call handlers all
implictly would generate a kernel oops if a check failed.
This is undesirable for a few reasons:
* System call handlers that acquire resources in the handler
have no good recourse for cleanup if a check fails.
* In some cases we may want to propagate a return value back
to the caller instead of just killing the calling thread,
even though the base API doesn't do these checks.
These macros now all return a value, if nonzero is returned
the check failed. K_OOPS() now wraps these calls to generate
a kernel oops.
At the moment, the policy for all APIs has not changed. They
still all oops upon a failed check/
The macros now use the Z_ notation for private APIs.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Some kernel APIs may need to allocate memory in order to function
correctly, especially if they are exposed to userspace where
buffers provided by user code cannot be trusted.
Instead of simply drawing from the system heap, specific pools
may instead be assigned to threads, and any requests made on
behalf of the calling thread will draw heap memory from that pool.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
MPU devices that enforce power-of-two alignment now
specify the size of the buffer used for the newlib heap.
This buffer will be properly aligned and a pointer
exposed in a kernel header, such that it can be added
to a user thread's memory domain configuration if
necessary.
MPU devices that don't have these restrictions allocate
the heap as normal.
In all cases, if an MPU/MMU region needs to be programmed,
the z_newlib_get_heap_bounds() API will return the necessary
information.
Given how precious MPU regions are, no automatic programming
of the MPU is done; applications will need to do this as
needed in their memory domain configurations.
On x86, the x86 MMU-specific code has been moved to arch/x86
using the new z_newlib_get_heap_bounds() API.
Fixes: #6814
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This was wrong in two ways, one subtle and one awful.
The subtle problem was that the IRQ lock isn't actually globally
recursive, it gets reset when you context switch (i.e. a _Swap()
implicitly releases and reacquires it). So the recursive count I was
keeping needs to be per-thread or else we risk deadlock any time we
swap away from a thread holding the lock.
And because part of my brain apparently knew this, there was an
"optimization" in the code that tested the current count vs. zero
outside the lock, on the argument that if it was non-zero we must
already hold the lock. Which would be true of a per-thread counter,
but NOT a global one: the other CPU may be holding that lock, and this
test will tell you *you* do. The upshot is that a recursive
irq_lock() would almost always SUCCEED INCORRECTLY when there was lock
contention. That this didn't break more things is amazing to me.
The rework is actually simpler than the original, thankfully. Though
there are some further subtleties:
* The lock state implied by irq_lock() allows the lock to be
implicitly released on context switch (i.e. you can _Swap() with the
lock held at a recursion level higher than 1, which needs to allow
other processes to run). So return paths into threads from _Swap()
and interrupt/exception exit need to check and restore the global
lock state, spinning as needed.
* The idle loop design specifies a k_cpu_idle() function that is on
common architectures expected to enable interrupts (for obvious
reasons), but there is no place to put non-arch code to wire it into
the global lock accounting. So on SMP, even CPU0 needs to use the
"dumb" spinning idle loop.
Finally this patch contains a simple bugfix too, found by inspection:
the interrupt return code used when CONFIG_SWITCH is enabled wasn't
correctly setting the active flag on the threads, opening up the
potential for a race that might result in a thread being scheduled on
two CPUs simultaneously.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Driver APIs might not implement all operations, making it possible for
a user thread to get the kernel to execute a function at 0x00000000.
Perform runtime checks in all the driver handlers, checking if they're
capable of performing the requested operation.
Fixes#6907.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
There was a ton of junk in this header. Pare it down to just the
stuff actually used by code outside of sched.c, move the needed
internal stuff into sched.c itself, and drop everything else.
Note that (other than the tiny inlines that remain here in the header)
the scheduler interface exposed to the rest of the system is now
composed of just 12 functions.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The POSIX layer had a simple ready_one_thread() utility. Move this to
the scheduler API (with a prepended underscore -- it's an internal
API) so that it can be synchronized along with the rest of the
scheduler.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Almost everywhere this was called, it was immediately followed by
_abort_thread_timeout(), for obvious reasons. The only exceptions
were in timeout and k_timer expiration (unifying these two would be
another good cleanup), which are peripheral parts of the scheduler and
can plausibly use a more "internal" API.
So make the common case the default, and expose the old behavior as
_unpend_thread_no_timeout(). (Along with identical changes for
_unpend_first_thread) Saves code bytes and simplifies scheduler
surface area for future synchronization work.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Now that other work has eliminated the two cases where we had to do a
reschedule "but yield even if we are cooperative", we can squash both
down to a single _reschedule() function which does almost exactly what
legacy _Swap() did, but wrapped as a proper scheduler API.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Everywhere the current thread is pended, the code is going to have to
do a _Swap() soon afterward, yet the scheduler API exposed these as
separate steps. Unify this pattern everywhere it appears, which saves
some code bytes and gets _Swap() out of the general scheduler API at
zero cost.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
There was a somewhat promiscuous pattern in the kernel where IPC
mechanisms would do something that might effect the current thread
choice, then check _must_switch_threads() (or occasionally
__must_switch_threads -- don't ask, the distinction is being replaced
by real English words), sometimes _is_in_isr() (but not always, even
in contexts where that looks like it would be a mistake), and then
call _Swap() if everything is OK, otherwise releasing the irq_lock().
Sometimes this was done directly, sometimes via the inverted test,
sometimes (poll, heh) by doing the test when the thread state was
modified and then needlessly passing the result up the call stack to
the point of the _Swap().
And some places were just calling _reschedule_threads(), which did all
this already.
Unify all this madness. The old _reschedule_threads() function has
split into two variants: _reschedule_yield() and
_reschedule_noyield(). The latter is the "normal" one that respects
the cooperative priority of the current thread (i.e. it won't switch
out even if there is a higher priority thread ready -- the current
thread has to pend itself first), the former is used in the handful of
places where code was doing a swap unconditionally, just to preserve
precise behavior across the refactor. I'm not at all convinced it
should exist...
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
A priority value cannot be simultaneously higher than the maximum
possible value and smaller than the minimum value. Rewrite the
_VALID_PRIO() macro as a function so that this if either of these
invariants are invalid, the priority is considered invalid.
Coverity-CID: 182584
Coverity-CID: 182585
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
The result of left shifting a bit into the sign-bit is undefined
behavior. This makes the offending shift operation unsigned.
Signed-off-by: Kristian Klomsten Skordal <kristian.skordal@nordicsemi.no>
The scheduler exposed two APIs to do the same thing:
_add_thread_to_ready_q() was a low level primitive that in most cases
was wrapped by _ready_thread(), which also (1) checks that the thread
_is_ready() or exits, (2) flags the thread as "started" to handle the
case of a thread running for the first time out of a waitq timeout,
and (3) signals a logger event.
As it turns out, all existing usage was already checking case #1.
Case #2 can be better handled in the timeout resume path instead of on
every call. And case #3 was probably wrong to have been skipping
anyway (there were paths that could make a thread runnable without
logging).
Now _add_thread_to_ready_q() is an internal scheduler API, as it
probably always should have been.
This also moves some asserts from the inline _ready_thread() wrapper
to the underlying true function for code size reasons, otherwise the
extra use of the inline added by this patch blows past code size
limits on Quark D2000.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The xtensa asm2 layer had a function to select the next switch handle
to return into following an exception. There is no arch-specific code
there, it's just scheduler logic. Move it to the scheduler where it
belongs.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
In SMP, the system timer is used for timeslicing on auxiliary CPUs,
but the base system timekeeping via _nano_sys_clock_tick_announce() is
still done on CPU0 only (because the framework isn't prepared for
asynchronous notification yet). Skip processing on CPU1+.
Also, due to a hardware interaction* that is difficult to work around,
timer initialization on the auxiliary CPUs is done at the very end of
the CPU bringup, just before the swap into the scheduler. A
smp_timer_init() API has been added for this purpose.
* On ESP-32, enabling the timer seems to result in a near-synchronous
interrupt being delivered despite my best attempts to keep it
masked, then blowing things up because the CPU record isn't set up
to handle it yet.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Now that all the pieces are in place, enable SMP for real:
Initialize the CPU records, launch the CPUs at the end of kernel
initialization, have them wait for a flag to release them into the
scheduler, then enter into the runnable threads via _Swap().
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The scheduler needs a few tweaks to work in SMP mode:
1. The "cache" field just doesn't work. With more than one CPU,
caching the highest priority thread isn't useful as you may need N
of them at any given time before another thread is returned to the
scheduler. You could recalculate it at every change, but that
provides no performance benefit. Remove.
2. The "bitmask" designed to prevent the need to individually check
priorities is likewise dropped. This could work, but in fact on
our only current SMP system and with current K_NUM_PRIOPRITIES
values it provides no real benefit.
3. The individual threads now have a "current cpu" and "active" flag
so that the choice of the next thread to run can correctly skip
threads that are active on other CPUs.
The upshot is that a decent amount of code gets #if'd out, and the new
SMP implementations for _get_highest_ready_prio() and
_get_next_ready_thread() are simpler and smaller, at the expense of
having to drop older optimizations.
Note that scheduler synchronization is unchanged: all scheduler APIs
used to require that an irq_lock() be held, which means that they now
require the global spinlock via the same API. This should be a very
early candidate for lock granularity attention!
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
When in SMP mode, the nested/irq_stack/current fields are specific to
the current CPU and not to the kernel as a whole, so we need an array
of these. Place them in a _cpu_t struct and implement a
_arch_curr_cpu() function to retrieve the pointer.
When not in SMP mode, the first CPU's fields are defined as a unioned
with the first _cpu_t record. This permits compatibility with legacy
assembly on other platforms. Long term, all users, including
uniprocessor architectures, should be updated to use the new scheme.
Fundamentally this is just renaming: the structure layout and runtime
code do not change on any existing platforms and won't until someone
defines a second CPU.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The xtensa-asm2 work included a patch that added nano_internal.h
includes in lots of places that needed to have _Swap defined, because
it had to break a cycle and this no longer got pulled in from the arch
headers.
Unfortunately those new includes created new and more amusing cycles
elsewhere which led to breakage on other platforms.
Break out the _Swap definition (only) into a separate header and use
that instead. Cleaner. Seems not to have any more hidden gotchas.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
When using _arch_switch() context switching, the thread return value
is a generic hook and not provided by the architecture.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The existing __swap() mechanism is too high level for some
applications because of its scheduler-awareness. This introduces a
new _arch_switch() mechanism, which is a simpler primitive that looks
like:
void _arch_switch(void *handle, void **old_handle_out);
The new thread handle (typically just a stack pointer) is specified
explicitly instead of being picked up from the scheduler by
per-architecture code, and on return the "old" thread handle that got
switched out is returned through the pointer.
The new primitive (currently available only on xtensa) is selected
when CONFIG_USE_SWITCH is "y". A new C _Swap() implementation based
on this primitive is then added which operates compatibly.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
K_NUM_PRIORITIES and K_NUM_PRIO_BITMAPS were defined in
nano_internal.h, but used in only a handful of places. Move to
kernel_structs.h (somewhat higher up in the hierarchy) to help with
include file cycle-breaking. Arguably they are a better fit there
anyway.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Rename the nano_internal.h to kernel_internal.h and modify the
header file name accordingly wherever it is used.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Add an architecure specfic code for the memory domain
configuration. This is needed to support a memory domain API
k_mem_domain_add_thread.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
Having two implementations of the same thing is bad,
especially when one can just call the other inline version.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Additional arch specific interfaces to handle memory domain
destroy and single partition removal.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
Kernel object metadata had an extra data field added recently to
store bounds for stack objects. Use this data field to assign
IDs to thread objects at build time. This has numerous advantages:
* Threads can be granted permissions on kernel objects before the
thread is initialized. Previously, it was necessary to call
k_thread_create() with a K_FOREVER delay, assign permissions, then
start the thread. Permissions are still completely cleared when
a thread exits.
* No need for runtime logic to manage thread IDs
* Build error if CONFIG_MAX_THREAD_BYTES is set too low
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Additional arch specific interfaces to handle memory domain
destroy and single partition removal.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
Currently this is defined as a k_thread_stack_t pointer.
However this isn't correct, stacks are defined as arrays. Extern
references to k_thread_stack_t doesn't work properly as the compiler
treats it as a pointer to the stack array and not the array itself.
Declaring as an unsized array of k_thread_stack_t doesn't work
well either. The least amount of confusion is to leave out the
pointer/array status completely, use pointers for function prototypes,
and define K_THREAD_STACK_EXTERN() to properly create an extern
reference.
The definitions for all functions and struct that use
k_thread_stack_t need to be updated, but code that uses them should
be unchanged.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We also need macros to assert that an object must be in an
uninitialized state. This will be used for validating thread
and stack objects to k_thread_create(), which must not be already
in use.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
It's currently too easy to run out of thread IDs as they
are never re-used on thread exit.
Now the kernel maintains a bitfield of in-use thread IDs,
updated on thread creation and termination. When a thread
exits, the permission bitfield for all kernel objects is
updated to revoke access for that retired thread ID, so that
a new thread re-using that ID will not gain access to objects
that it should not have.
Because of these runtime updates, setting the permission
bitmap for an object to all ones for a "public" object doesn't
work properly any more; a flag is now set for this instead.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This will allow these thread objects to be re-used.
_mark_thread_as_dead() removed, it was only being called in one
place.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
API to assist with re-using objects, such as terminated threads or
kernel objects returned to a pool.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Use some preprocessor trickery to automatically deduce the amount of
arguments for the various _SYSCALL_HANDLERn() macros. Makes the grunt
work of converting a bunch of kernel APIs to system calls slightly
easier.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Does the opposite of k_object_access_grant(); the provided thread will
lose access to that kernel object.
If invoked from userspace the caller must hace sufficient access
to that object and permission on the thread being revoked access.
Fix documentation for k_object_access_grant() API to reflect that
permission on the thread parameter is needed as well.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
By default, threads are created only having access to their own thread
object and nothing else. This new flag to k_thread_create() gives the
thread access to all objects that the parent had at the time it was
created, with the exception of the parent thread itself.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We now have macros which should significantly reduce the amount of
boilerplate involved with defining system call handlers.
- Macros which define the proper prototype based on number of arguments
- "SIMPLE" variants which create handlers that don't need anything
other than object verification
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
- Dumping error messages split from _k_object_validate(), to avoid spam
in test cases that are expected to have failure result.
- _k_object_find() prototype moved to syscall_handler.h
- Clean up k_object_access() implementation to avoid double object
lookup and use single validation function
- Added comments, minor whitespace changes
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Computing the total size of the array need to handle the case where
the product overflow a 32-bit unsigned integer.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Instead of boolean arguments to indicate memory read/write
permissions, or init/non-init APIs, new macros are introduced
which bake the semantics directly into the name of the macro.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Expecting stringified expressions to be completely comprehensible to end
users is wishful thinking; we really need to express what a failed
system call verification step means in human terms in most cases.
Memory buffer and kernel object checks now are implemented in terms of
_SYSCALL_VERIFY_MSG.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This API only gets used inside system call handlers and a specific test
case dedicated to it. Move definition to the private kernel header along
with the rest of the defines for system call handlers.
A non-userspace inline variant of this function is unnecessary and has
been deleted.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Add the following application-facing memory domain APIs:
k_mem_domain_init() - to initialize a memory domain
k_mem_domain_destroy() - to destroy a memory domain
k_mem_domain_add_partition() - to add a partition into a domain
k_mem_domain_remove_partition() - to remove a partition from a domain
k_mem_domain_add_thread() - to add a thread into a domain
k_mem_domain_remove_thread() - to remove a thread from a domain
A memory domain would contain some number of memory partitions.
A memory partition is a memory region (might be RAM, peripheral
registers, flash...) with specific attributes (access permission,
e.g. privileged read/write, unprivileged read-only, execute never...).
Memory partitions would be defined by set of MPU regions or MMU tables
underneath.
A thread could only belong to a single memory domain any point in time
but a memory domain could contain multiple threads.
Threads in the same memory domain would have the same access permission
to the memory partitions belong to the memory domain.
The memory domain APIs are used by unprivileged threads to share data
to the threads in the same memory and protect sensitive data from
threads outside their domain. It is not only for improving the security
but also useful for debugging (unexpected access would cause exception).
Jira: ZEP-2281
Signed-off-by: Chunlin Han <chunlin.han@linaro.org>
Everything get passed to handlers as u32_t, make it simpler to check
something that is known to be a pointer, like we already do with
_SYSCALL_IS_OBJ().
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
To define a system call, it's now sufficient to simply tag the inline
prototype with "__syscall" or "__syscall_inline" and include a special
generated header at the end of the header file.
The system call dispatch table and enumeration of system call IDs is now
automatically generated.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
- syscall.h now contains those APIs needed to support invoking calls
from user code. Some stuff moved out of main kernel.h.
- syscall_handler.h now contains directives useful for implementing
system call handler functions. This header is not pulled in by
kernel.h and is intended to be used by C files implementing kernel
system calls and driver subsystem APIs.
- syscall_list.h now contains the #defines for system call IDs. This
list is expected to grow quite large so it is put in its own header.
This is now an enumerated type instead of defines to make things
easier as we introduce system calls over the new few months. In the
fullness of time when we desire to have a fixed userspace/kernel ABI,
this can always be converted to defines.
Some new code added:
- _SYSCALL_MEMORY() macro added to check memory regions passed up from
userspace in handler functions
- _syscall_invoke{7...10}() inline functions declare for invoking system
calls with more than 6 arguments. 10 was chosen as the limit as that
corresponds to the largest arg list we currently have
which is for k_thread_create()
Other changes
- auto-generated K_SYSCALL_DECLARE* macros documented
- _k_syscall_table in userspace.c is not a placeholder. There's no
strong need to generate it and doing so would require the introduction
of a third build phase.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
* Instead of a common system call entry function, we instead create a
table mapping system call ids to handler skeleton functions which are
invoked directly by the architecture code which receives the system
call.
* system call handler prototype specified. All but the most trivial
system calls will implement one of these. They validate all the
arguments, including verifying kernel/device object pointers, ensuring
that the calling thread has appropriate access to any memory buffers
passed in, and performing other parameter checks that the base system
call implementation does not check, or only checks with __ASSERT().
It's only possible to install a system call implementation directly
inside this table if the implementation has a return value and requires
no validation of any of its arguments.
A sample handler implementation for k_mutex_unlock() might look like:
u32_t _syscall_k_mutex_unlock(u32_t mutex_arg, u32_t arg2, u32_t arg3,
u32_t arg4, u32_t arg5, void *ssf)
{
struct k_mutex *mutex = (struct k_mutex *)mutex_arg;
_SYSCALL_ARG1;
_SYSCALL_IS_OBJ(mutex, K_OBJ_MUTEX, 0, ssf);
_SYSCALL_VERIFY(mutex->lock_count > 0, ssf);
_SYSCALL_VERIFY(mutex->owner == _current, ssf);
k_mutex_unlock(mutex);
return 0;
}
* the x86 port modified to work with the system call table instead of
calling a common handler function. fixed an issue where registers being
changed could confuse the compiler has been fixed; all registers, even
ones used for parameters, must be preserved across the system call.
* a new arch API for producing a kernel oops when validating system call
arguments added. The debug information reported will be from the system
call site and not inside the handler function.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Based on work by Chunlin Han <chunlin.han@linaro.org>.
This defines the interfaces that architectures will need to implement in
order to support memory domains in either MMU or MPU hardware.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
