This renames the obj_list element in struct dyn_obj to
dobj_list, to avoid identifier collision with the static
obj_list defined in userspace.c.
Violation of MISRA rule 5.9.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Add a 'U' suffix to values when computing and comparing against
unsigned variables and other related fixes of the same MISRA rule (10.4)
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This allows allocating dynamic kernel objects with memory alignment
requirements. The first candidate is for thread objects where,
on some architectures, it must be aligned for saving/restoring
registers.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Most of kernel files where declaring os module without providing
log level. Because of that default log level was used instead of
CONFIG_KERNEL_LOG_LEVEL.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
k_object_alloc(K_OBJ_THREAD) returns a usable struct k_thread pointer.
This pointer is 4 byte aligned. On x86 and x86_64 struct _thread_arch
has a member which requires alignment. Since this is currently not
supported k_object_alloc(K_OBJ_THREAD) now returns an error instead of
a misaligned pointer.
Signed-off-by: Maximilian Bachmann <m.bachmann@acontis.com>
The type for the thread index returned by thread_index_get() must be
casted to int when comparing with (-1). Directly using uintptr_t is
breaking the ARMv8 implementation where where the check (index != -1) is
verified also when no thread index is returned.
Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Now that device_api attribute is unmodified at runtime, as well as all
the other attributes, it is possible to switch all device driver
instance to be constant.
A coccinelle rule is used for this:
@r_const_dev_1
disable optional_qualifier
@
@@
-struct device *
+const struct device *
@r_const_dev_2
disable optional_qualifier
@
@@
-struct device * const
+const struct device *
Fixes#27399
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
The k_object API associates mutable state structures with known kernel
objects to support userspace. The kernel objects themselves are not
modified by the API, and in some cases (e.g. device structures) may be
const-qualified. Update the API so that pointers to these const
kernel objects can be passed without casting away the const qualifier.
Fixes#27399
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
Following are the changes to variable names that are matching
with tag names (Rule 5.7 violations)
In kernel.h, event_type is matching with a tag name in
lib/os/onoff.c. Added a _ prefix to event_type and
also to the macro argument names.
In userspace.c, *dyn_obj is matching with the tag name
dyn_obj in the file itslef. Changed it to dyn
In device.h, device_mmio.h, init.h and init.c,
changed the *device to dev. Except for one change in
init.h
Signed-off-by: Spoorthy Priya Yerabolu <spoorthy.priya.yerabolu@intel.com>
These stacks are appropriate for threads that run purely in
supervisor mode, and also as stacks for interrupt and exception
handling.
Two new arch defines are introduced:
- ARCH_KERNEL_STACK_GUARD_SIZE
- ARCH_KERNEL_STACK_OBJ_ALIGN
New public declaration macros:
- K_KERNEL_STACK_RESERVED
- K_KERNEL_STACK_EXTERN
- K_KERNEL_STACK_DEFINE
- K_KERNEL_STACK_ARRAY_DEFINE
- K_KERNEL_STACK_MEMBER
- K_KERNEL_STACK_SIZEOF
If user mode is not enabled, K_KERNEL_STACK_* and K_THREAD_STACK_*
are equivalent.
Separately generated privilege elevation stacks are now declared
like kernel stacks, removing the need for K_PRIVILEGE_STACK_ALIGN.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We now have a low-level function z_dynamic_object_create()
which is not a system call and is used for installing
kernel objects that are not supported by k_object_alloc().
Checking for valid object type enumeration values moved
completely to the implementation function.
A few debug messages and comments were improved.
Futexes and sys_mutexes are now properly excluded from
dynamic generation.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This was passing along _current->ssf, but these types of bad
syscalls do not go through the z_mrsh mechanism and was
passing stale data.
We have the syscall stack frame already as an argument,
propagate that so it works properly.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This never needed to be put in a separate gperf table.
Privilege mode stacks can be generated by the main
gen_kobject_list.py logic, which we do here.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Private type, internal to the kernel, not directly associated
with any k_object_* APIs. Is the return value of z_object_find().
Rename to struct z_object.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Rather than stuffing various values in a uintptr_t based on
type using casts, use a union for this instead.
No functional difference, but the semantics of the data member
are now much clearer to the casual observer since it is now
formally defined by this union.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The syscall exception frame was stored on the CPU struct during
syscall execution, but that's not right. System calls might "feel
like" exceptions, but they're actually perfectly normal kernel mode
code and can be preempted and migrated between CPUs at any time.
Put the field on the thread struct.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
We have been using thread, th and t for thread variables making the code
less readable, especially when we use t for timeouts and other time
related variables. Just use thread where possible and keep things
consistent.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
64-bit systems generate some compiler warnings about
data type sizes, use uintptr_t where int/u32_t was being cast
to void *.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Remove leading/trailing blank lines in .c, .h, .py, .rst, .yml, and
.yaml files.
Will avoid failures with the new CI test in
https://github.com/zephyrproject-rtos/ci-tools/pull/112, though it only
checks changed files.
Move the 'target-notes' target in boards/xtensa/odroid_go/doc/index.rst
to get rid of the trailing blank line there. It was probably misplaced.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Promote the private z_arch_* namespace, which specifies
the interface between the core kernel and the
architecture code, to a new top-level namespace named
arch_*.
This allows our documentation generation to create
online documentation for this set of interfaces,
and this set of interfaces is worth treating in a
more formal way anyway.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We need to pass system call args using a register-width
data type and not hard-code this to u32_t.
Signed-off-by: Andrew Boie <andrew.p.boie@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>
move misc/rb.h to sys/rb.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
move misc/printk.h to sys/printk.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
move misc/mutex.h to sys/mutex.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
move misc/math_extras.h to sys/math_extras.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
move misc/libc-hooks.h to sys/libc-hooks.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
move sys_io.h to sys/sys_io.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
We had both kernel and os as domains covering low level layers, just use
one and fix the issue of the os domain not being registered.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Use the new math_extras functions instead of calling builtins directly.
Change a few local variables to size_t after checking that all uses of
the variable actually expects a size_t.
Signed-off-by: Jakob Olesen <jolesen@fb.com>
We don't actually need spinlocks here.
For user_copy(), we are checking that the pointer/size passed in
from user mode represents an area that the thread can read or
write to. Then we do a memcpy into the kernel-side buffer,
which is used from then on. It's OK if another thread scribbles
on the buffer contents during the copy, as we have not yet
begun any examination of its contents yet.
For the z_user_string*_copy() functions, it's also possible
that another thread could scribble on the string contents,
but we do no analysis of the string other than to establish
a length. We just need to ensure that when these functions
exit, the copied string is NULL terminated.
For SMP, the spinlocks are removed as they will not prevent a
thread running on another CPU from changing the buffer/string
contents, we just need to safely deal with that possibility.
For UP, the locks do prevent another thread from stepping
in, but it's better to just safely deal with it rather than
affect the interrupt latency of the system.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
For systems without userspace enabled, these work the same
as a k_mutex.
For systems with userspace, the sys_mutex may exist in user
memory. It is still tracked as a kernel object, but has an
underlying k_mutex that is looked up in the kernel object
table.
Future enhancements will optimize sys_mutex to not require
syscalls for uncontended sys_mutexes, using atomic ops
instead.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Controlling expression of if and iteration statements must have a
boolean type.
MISRA-C rule 14.4
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Update reserved function names starting with one underscore, replacing
them as follows:
'_k_' with 'z_'
'_K_' with 'Z_'
'_handler_' with 'z_handl_'
'_Cstart' with 'z_cstart'
'_Swap' with 'z_swap'
This renaming is done on both global and those static function names
in kernel/include and include/. Other static function names in kernel/
are renamed by removing the leading underscore. Other function names
not starting with any prefix listed above are renamed starting with
a 'z_' or 'Z_' prefix.
Function names starting with two or three leading underscores are not
automatcally renamed since these names will collide with the variants
with two or three leading underscores.
Various generator scripts have also been updated as well as perf,
linker and usb files. These are
drivers/serial/uart_handlers.c
include/linker/kobject-text.ld
kernel/include/syscall_handler.h
scripts/gen_kobject_list.py
scripts/gen_syscall_header.py
Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>
The mbedtls library has some globals which results in faults
when user mode tries to access them.
Instantiate a memory partition for mbedtls's globals.
The linker will place all globals found by building this
library into this partition.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Some init tasks may use some bss app memory areas and
expect them to be zeroed out. Do this much earlier
in the boot process, before any of the init tasks
run.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We used to leave byte-long placeholder symbols to ensure
that empty application memory sections did not cause
build errors that were very difficult to understand.
Now we use some relatively portable inline assembly to
generate a symbol, but don't take up any extra space.
The malloc and libc partitions are now only instantiated
if there is some data to put in them.
Fixes: #13923
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is an integral part of userspace and cannot be used
on its own. Fold into the main userspace configuration.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We need a generic name for the partition containing
essential C library globals. We're going to need to
add the stack canary guard to this area so user mode
can read it.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This port is a little different. Most subsystem synchronization uses
simple critical sections that can be replaced with global or
per-object spinlocks. But the userspace code was heavily exploiting
the fact that irq_lock was recursive and could be taken at any time.
So outer functions were doing locking and then calling into inner
helpers that would take their own lock (because they were called from
other contexts that did not lock).
Rather than try to rework this right now, this just creates a set of
spinlocks corresponding to the recursive states in which they are
taken, to preserve the existing semantics exactly.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
Dynamic kernel objects enforce that the permission state
of an object is also a reference count; using a kernel
object without permission regardless of caller privilege
level is a programming bug.
However, this is not the case for static objects. In
particular, supervisor threads are allowed to use any
object they like without worrying about permissions, and
the logic here was causing cleanup functions to be called
over and over again on kernel objects that were actually
in use.
The automatic cleanup mechanism was intended for
dynamic objects anyway, so just skip it entirely for
static objects.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
MISRA-C says all declarations of an object or function must use the
same name and qualifiers.
MISRA-C rule 8.3
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Some places are using the same tag identifier with different types.
This is a MISRA-C violation and makes the code less readable.
MISRA-C rule 5.7
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
A final else statement must be provided when an if statement is
followed by one or more else if.
MISRA-C rule 15.7
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>
Make if statement using pointers explicitly check whether the value is
NULL or not.
The C standard does not say that the null pointer is the same as the
pointer to memory address 0 and because of this is a good practice
always compare with the macro NULL.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
The return of memset is never checked. This patch explicitly ignore
the return to avoid MISRA-C violations.
The only directory excluded directory was ext/* since it contains
only imported code.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
MISRA-C requires that every switch clause has a break instruction.
Changing gen_kobject_list script to generates compliance code.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
memcpy always return a pointer to dest, it can be ignored. Just making
it explicitly so compilers will never raise warnings/errors to this.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
irq_lock returns an unsigned int, though, several places was using
signed int. This commit fix this behaviour.
In order to avoid this error happens again, a coccinelle script was
added and can be used to check violations.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Socket APIs pass pointers to these disguised as file descriptors.
This lets us effectively validate them.
Kernel objects now can have Kconfig dependencies specified, in case
certain structs are not available in all configurations.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Kernel threads created at build time have unique indexes to map them
into various bitarrays. This patch extends these indexes to
dynamically created threads where the associated kernel objects are
allocated at runtime.
Fixes: #9081
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
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>
This used to be done by hand but can easily be generated like
we do other switch statements based on object type.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Similar to what has been done with pipes and message queues,
user mode can't be trusted to provide a buffer for the kernel
to use. Remove k_stack_init() as a syscall and offer
k_stack_alloc_init() which allocates a buffer from the caller's
resource pool.
Fixes#7285
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
User mode can't be trusted to provide a memory buffer to
k_msgq_init(). Introduce k_msgq_alloc_init() which allocates
the buffer out of the calling thread's resource pool and expose
that as a system call instead.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
User mode can't be trusted to provide the kernel buffers for
internal use. The syscall for k_pipe_init() has been removed
in favor of a new API to draw the buffer memory from the
calling thread's resource pool.
K_PIPE_DEFINE() now properly locates the allocated buffer into
kernel memory.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Dynamic kernel objects no longer is hard-coded to use the kernel
heap. Instead, objects will now be drawn from the calling thread's
resource pool.
Since we now have a reference counting mechanism, if an object
loses all its references and it was dynamically allocated, it will
be automatically freed.
A parallel dlist is added for efficient iteration over the set of
all dynamic objects, allowing deletion during iteration.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
An object's set of permissions is now also used as a form
of reference counting. If an object's permission bitmap gets
completely cleared, it is now possible to specify object type
specific cleanup functions to be implicitly called.
Currently no objects are enabled yet. Forthcoming patches
will do this on a per object basis.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Forthcoming patches will dual-purpose an object's permission
bitfield as also reference tracking for kernel objects, used to
handle automatic freeing of resources.
We do not want to allow user thread A to revoke thread B's access
to some object O if B is in the middle of an API call using O.
However we do want to allow threads to revoke their own access to
an object, so introduce a new API and syscall for that.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Adding a new kernel object type or driver subsystem requires changes
in various different places. This patch makes it easier to create
those devices by generating as much as possible in compile time.
No behavior change.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
A red-black tree is maintained containing the metadata for all
dynamically created kernel objects, which are allocated out of the
system heap.
Currently, k_object_alloc() and k_object_free() are supervisor-only.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Names that begin with an underscore are reserved by the C standard.
This patch does not change names of functions defined and implemented
in header files.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
As per current policy of requiring supervisor mode to register
callbacks, dma_config() is omitted.
A note added about checking the channel ID for start/stop, current
implementations already do this but best make it explicitly
documented.
Signed-off-by: Andrew Boie <andrew.p.boie@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>
This should clear up some of the confusion with random number
generators and drivers that obtain entropy from the hardware. Also,
many hardware number generators have limited bandwidth, so it's natural
for their output to be only used for seeding a random number generator.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Use-cases for these subsystems appear to be limited to board/SOC
code, network stacks, or other drivers, no need to expose to
userspace at this time. If we change our minds it's easy enough
to add them back.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We need to track permission on stack memory regions like we do
with other kernel objects. We want stacks to live in a memory
area that is outside the scope of memory domain permission
management. We need to be able track what stacks are in use,
and what stacks may be used by user threads trying to call
k_thread_create().
Some special handling is needed because thread stacks appear as
variously-sized arrays of struct _k_thread_stack_element which is
just a char. We need the entire array to be considered an object,
but also properly handle arrays of stacks.
Validation of stacks also requires that the bounds of the stack
are not exceeded. Various approaches were considered. Storing
the size in some header region of the stack itself would not allow
the stack to live in 'noinit'. Having a stack object be a data
structure that points to the stack buffer would confound our
current APIs for declaring stacks as arrays or struct members.
In the end, the struct _k_object was extended to store this size.
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>
This is too powerful for user mode, the other access APIs
require explicit permissions on the threads that are being
granted access.
The API is no longer exposed as a system call and hence will
only be usable by supervisor threads.
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>
We got rid of letting uninitialized objects being a free-for-all
and permission to do stuff on an object is now done explicitly.
If a user thread is initializing an object, they will already have
permission on it.
If a supervisor thread is initializing an object, that supervisor
thread may or may not want that object added to its set of object
permissions for purposes of permission inheritance or dropping to
user mode.
Resetting all permissions on initialization makes objects much
harder to share and re-use; for example other threads will lose
access if some thread re-inits a shared semaphore.
For all these reasons, just keep the permissions as they are when
an object is initialized.
We will need some policy for permission reset when objects are
requested and released from pools, but the pool implementation
should take care of that.
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>
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>
- 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>
The old policy was that objects that are not marked as initialized may
be claimed by any thread, user or kernel.
This has some undesirable implications:
- Kernel objects that were initailized at build time via some
_<object name>_INITIALIZER macro, not intended for userspace to ever
use, could be 'stolen' if their memory addresses were figured out and
_k_object_init() was never called on them.
- In general, a malicious thread could initialize all unclaimed objects
it could find, resulting in denial of service for the threads that
these objects were intended for.
Now, performing any operation in user mode on a kernel object,
initialized or not, required that the calling user thread have
permission on it. Such permission would have to be explicitly granted or
inherited from a supervisor thread, as with this change only supervisor
thread will be able to claim uninitialized objects in this way.
If an uninitialized kernel object has permissions granted to multiple
threads, whatever thread actually initializes the object will reset all
permission bits to zero and grant only the calling thread access to that
object.
In other words, granting access to an uninitialized object to several
threads means that "whichever of these threads (or any kernel thread)
who actually initializes this object will obtain exclusive access to
that object, which it then may grant to other threads as it sees fit."
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We now show the caller's thread ID and dump out the permissions array
for the object that failed the check.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
These are removed as the APIs that use them are not suitable for
exporting to userspace.
- Kernel workqueues run in supervisor mode, so it would not be
appropriate to allow user threads to submit work to them. A future
enhancement may extend or introduce parallel API where the workqueue
threads may run in user mode (or leave as an exercise to the user).
- Kernel slabs store private bookkeeping data inside the
user-accessible slab buffers themselves. Alternate APIs are planned
here for managing slabs of kernel objects, implemented within the
runtime library and not the kernel.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
These modify kernel object metadata and are intended to be callable from
user threads, need a privilege elevation for these to work.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
