There are no longer per-partition initialization functions.
Instead, we iterate over all of them at boot to set up the
derived k_mem_partitions properly.
Some ARC-specific hacks that should never have been applied
have been removed from the userspace test.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The public APIs for application shared memory are now
properly documented and conform to zephyr naming
conventions.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The app shared memory macros for declaring domains provide
no value, despite the stated intentions.
Just declare memory domains using the standard APIs for it.
To support this, symbols declared for app shared memory
partitions now are struct k_mem_partition, which can be
passed to the k_mem_domain APIs as normal, instead of the
app_region structs which are of no interest to the end
user.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
In general driver system calls are implemented at a subsystem
layer. However, some drivers may have capabilities specific to
the hardware not covered by the subsystem API. Such drivers may
want to define their own system calls.
This macro makes it simple to validate in the driver-specific
system call handlers that not only does the untrusted device
pointer correspond to the expected subsystem, initialization
state, and caller permissions, but also that the device object
is an instance of a specific driver (and not just any driver in
that subsystem).
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Application shared memory API uses 'appmem_' prefix for
its functions and macros. This commit updates the respective
documentation to align with the API convention.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
The phrase "object must have _k_object_init() on it at some point"
visibly misses "called".
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Fixing a few minor typo fixes in kernel/mem_domain.c
and the respective documentation section.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
Summary: revised attempt at addressing issue 6290. The
following provides an alternative to using
CONFIG_APPLICATION_MEMORY by compartmentalizing data into
Memory Domains. Dependent on MPU limitations, supports
compartmentalized Memory Domains for 1...N logical
applications. This is considered an initial attempt at
designing flexible compartmentalized Memory Domains for
multiple logical applications and, with the provided python
script and edited CMakeLists.txt, provides support for power
of 2 aligned MPU architectures.
Overview: The current patch uses qualifiers to group data into
subsections. The qualifier usage allows for dynamic subsection
creation and affords the developer a large amount of flexibility
in the grouping, naming, and size of the resulting partitions and
domains that are built on these subsections. By additional macro
calls, functions are created that help calculate the size,
address, and permissions for the subsections and enable the
developer to control application data in specified partitions and
memory domains.
Background: Initial attempts focused on creating a single
section in the linker script that then contained internally
grouped variables/data to allow MPU/MMU alignment and protection.
This did not provide additional functionality beyond
CONFIG_APPLICATION_MEMORY as we were unable to reliably group
data or determine their grouping via exported linker symbols.
Thus, the resulting decision was made to dynamically create
subsections using the current qualifier method. An attempt to
group the data by object file was tested, but found that this
broke applications such as ztest where two object files are
created: ztest and main. This also creates an issue of grouping
the two object files together in the same memory domain while
also allowing for compartmenting other data among threads.
Because it is not possible to know a) the name of the partition
and thus the symbol in the linker, b) the size of all the data
in the subsection, nor c) the overall number of partitions
created by the developer, it was not feasible to align the
subsections at compile time without using dynamically generated
linker script for MPU architectures requiring power of 2
alignment.
In order to provide support for MPU architectures that require a
power of 2 alignment, a python script is run at build prior to
when linker_priv_stacks.cmd is generated. This script scans the
built object files for all possible partitions and the names given
to them. It then generates a linker file (app_smem.ld) that is
included in the main linker.ld file. This app_smem.ld allows the
compiler and linker to then create each subsection and align to
the next power of 2.
Usage:
- Requires: app_memory/app_memdomain.h .
- _app_dmem(id) marks a variable to be placed into a data
section for memory partition id.
- _app_bmem(id) marks a variable to be placed into a bss
section for memory partition id.
- These are seen in the linker.map as "data_smem_id" and
"data_smem_idb".
- To create a k_mem_partition, call the macro
app_mem_partition(part0) where "part0" is the name then used to
refer to that partition. This macro only creates a function and
necessary data structures for the later "initialization".
- To create a memory domain for the partition, the macro
app_mem_domain(dom0) is called where "dom0" is the name then
used for the memory domain.
- To initialize the partition (effectively adding the partition
to a linked list), init_part_part0() is called. This is followed
by init_app_memory(), which walks all partitions in the linked
list and calculates the sizes for each partition.
- Once the partition is initialized, the domain can be
initialized with init_domain_dom0(part0) which initializes the
domain with partition part0.
- After the domain has been initialized, the current thread
can be added using add_thread_dom0(k_current_get()).
- The code used in ztests ans kernel/init has been added under
a conditional #ifdef to isolate the code from other tests.
The userspace test CMakeLists.txt file has commands to insert
the CONFIG_APP_SHARED_MEM definition into the required build
targets.
Example:
/* create partition at top of file outside functions */
app_mem_partition(part0);
/* create domain */
app_mem_domain(dom0);
_app_dmem(dom0) int var1;
_app_bmem(dom0) static volatile int var2;
int main()
{
init_part_part0();
init_app_memory();
init_domain_dom0(part0);
add_thread_dom0(k_current_get());
...
}
- If multiple partitions are being created, a variadic
preprocessor macro can be used as provided in
app_macro_support.h:
FOR_EACH(app_mem_partition, part0, part1, part2);
or, for multiple domains, similarly:
FOR_EACH(app_mem_domain, dom0, dom1);
Similarly, the init_part_* can also be used in the macro:
FOR_EACH(init_part, part0, part1, part2);
Testing:
- This has been successfully tested on qemu_x86 and the
ARM frdm_k64f board. It compiles and builds power of 2
aligned subsections for the linker script on the 96b_carbon
boards. These power of 2 alignments have been checked by
hand and are viewable in the zephyr.map file that is
produced during build. However, due to a shortage of
available MPU regions on the 96b_carbon board, we are unable
to test this.
- When run on the 96b_carbon board, the test suite will
enter execution, but each individaul test will fail due to
an MPU FAULT. This is expected as the required number of
MPU regions exceeds the number allowed due to the static
allocation. As the MPU driver does not detect this issue,
the fault occurs because the data being accessed has been
placed outside the active MPU region.
- This now compiles successfully for the ARC boards
em_starterkit_em7d and em_starterkit_em7d_v22. However,
as we lack ARC hardware to run this build on, we are unable
to test this build.
Current known issues:
1) While the script and edited CMakeLists.txt creates the
ability to align to the next power of 2, this does not
address the shortage of available MPU regions on certain
devices (e.g. 96b_carbon). In testing the APB and PPB
regions were commented out.
2) checkpatch.pl lists several issues regarding the
following:
a) Complex macros. The FOR_EACH macros as defined in
app_macro_support.h are listed as complex macros needing
parentheses. Adding parentheses breaks their
functionality, and we have otherwise been unable to
resolve the reported error.
b) __aligned() preferred. The _app_dmem_pad() and
_app_bmem_pad() macros give warnings that __aligned()
is preferred. Prior iterations had this implementation,
which resulted in errors due to "complex macros".
c) Trailing semicolon. The macro init_part(name) has
a trailing semicolon as the semicolon is needed for the
inlined macro call that is generated when this macro
expands.
Update: updated to alternative CONFIG_APPLCATION_MEMORY.
Added config option CONFIG_APP_SHARED_MEM to enable a new section
app_smem to contain the shared memory component. This commit
seperates the Kconfig definition from the definition used for the
conditional code. The change is in response to changes in the
way the build system treats definitions. The python script used
to generate a linker script for app_smem was also midified to
simplify the alignment directives. A default linker script
app_smem.ld was added to remove the conditional includes dependency
on CONFIG_APP_SHARED_MEM. By addining the default linker script
the prebuild stages link properly prior to the python script running
Signed-off-by: Joshua Domagalski <jedomag@tycho.nsa.gov>
Signed-off-by: Shawn Mosley <smmosle@tycho.nsa.gov>
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>
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>
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>
This patch adds documentation on the design and implementation of stack
objects for architectures which utilize MPU backed stack and memory
protection.
Signed-off-by: Andy Gross <andy.gross@linaro.org>
Remove thread from memory domain API (k_mem_domain_remove_thread())has
only one argument which is thread ID as per the implementation whereas
documentation says there has to be two arguments, memory domain and
thread ID.Memory domain argument is not required as a thread belongs
to single memory domain at any point in time. Also memory domain
initialisation function (k_mem_domain_init()) should accept only 3
arguments i.e, memory domain name, number of parts and array of
pointers to the memory domain, instead of 4.
Signed-off-by: Spoorthi K <spoorthi.k@intel.com>
The expected order for heading levels in our ReST documents is # for H1,
* for H2, = for H3, and - for H4. Some documents snuck in without
following this guideline.
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
The existing docs immediately dive into the details without providing
the user with any kind of high level overview or description of the
threat model.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit fixes
https://github.com/zephyrproject-rtos/zephyr/issues/5008.
It does so by splitting up gen_syscalls.py into two scripts with a
json metadata file to communicate syscall metadata between them. The
parsing script parses header files from include/ and writes syscall
metadata to a file if the contents changed. The generation script
reads from the json file and generates syscall code.
The build system DAG now looks like this:
always_rebuild -> json -> syscalls -> offset.o
The script for generating json will do so only if the content changes,
this ensures that the entire DAG does not always do a full rebuild.
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
This gives more detail on how system calls with large argument
lists, or large return value types should be handled.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This initial batch of documentation describes policies and
mechanism related to kernel objects and system calls.
Some details on porting user mode to a new arch have been
provided in the architecture porting guide.
Thread documentation updated with some user mode consideration.
This is not the final documentation, more to come in subsequent
patches.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
