Added architecture specific support for memory domain destroy
and remove partition for arm and nxp. An optimized version of
remove partition was also added.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
This is intended for memory-constrained systems and will save
4K per thread, since we will no longer reserve room for or
activate a kernel stack guard page.
If CONFIG_USERSPACE is enabled, stack overflows will still be
caught in some situations:
1) User mode threads overflowing stack, since it crashes into the
kernel stack page
2) Supervisor mode threads overflowing stack, since the kernel
stack page is marked non-present for non-user threads
Stack overflows will not be caught:
1) When handling a system call
2) When the interrupt stack overflows
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is an introductory port for Zephyr to be run as a Jailhouse
hypervisor[1]'s "inmate cell", on x86 64-bit CPUs (running on 32-bit
mode). This was tested with their "tiny-demo" inmate demo cell
configuration, which takes one of the CPUs of the QEMU-VM root cell
config, along with some RAM and serial controller access (it will even
do nice things like reserving some L3 cache for it via Intel CAT) and
Zephyr samples:
- hello_world
- philosophers
- synchronization
The final binary receives an additional boot sequence preamble that
conforms to Jailhouse's expectations (starts at 0x0 in real mode). It
will put the processor in 32-bit protected mode and then proceed to
Zephyr's __start function.
Testing it is just a matter of:
$ mmake -C samples/<sample_dir> BOARD=x86_jailhouse JAILHOUSE_QEMU_IMG_FILE=<path_to_image.qcow2> run
$ sudo insmod <path to jailhouse.ko>
$ sudo jailhouse enable <path to configs/qemu-x86.cell>
$ sudo jailhouse cell create <path to configs/tiny-demo.cell>
$ sudo mount -t 9p -o trans/virtio host /mnt
$ sudo jailhouse cell load tiny-demo /mnt/zephyr.bin
$ sudo jailhouse cell start tiny-demo
$ sudo jailhouse cell destroy tiny-demo
$ sudo jailhouse disable
$ sudo rmmod jailhouse
For the hello_world demo case, one should then get QEMU's serial port
output similar to:
"""
Created cell "tiny-demo"
Page pool usage after cell creation: mem 275/1480, remap 65607/131072
Cell "tiny-demo" can be loaded
CPU 3 received SIPI, vector 100
Started cell "tiny-demo"
***** BOOTING ZEPHYR OS v1.9.0 - BUILD: Sep 12 2017 20:03:22 *****
Hello World! x86
"""
Note that the Jailhouse's root cell *has to be started in xAPIC
mode* (kernel command line argument 'nox2apic') in order for this to
work. x2APIC support and its reasoning will come on a separate commit.
As a reminder, the make run target introduced for x86_jailhouse board
involves a root cell image with Jailhouse in it, to be launched and then
partitioned (with >= 2 64-bit CPUs in it).
Inmate cell configs with no JAILHOUSE_CELL_PASSIVE_COMMREG flag
set (e.g. apic-demo one) would need extra code in Zephyr to deal with
cell shutdown command responses from the hypervisor.
You may want to fine tune CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC for your
specific CPU—there is no detection from Zephyr with regard to that.
Other config differences from pristine QEMU defaults worth of mention
are:
- there is no HPET when running as Jailhouse guest. We use the LOAPIC
timer, instead
- there is no PIC_DISABLE, because there is no 8259A PIC when running
as a Jailhouse guest
- XIP makes no sense also when running as Jailhouse guest, and both
PHYS_RAM_ADDR/PHYS_LOAD_ADD are set to zero, what tiny-demo cell
config is set to
This opens up new possibilities for Zephyr, so that usages beyond just
MCUs come to the table. I see special demand coming from
functional-safety related use cases on industry, automotive, etc.
[1] https://github.com/siemens/jailhouse
Reference to Jailhouse's booting preamble code:
Origin: Jailhouse
License: BSD 2-Clause
URL: https://github.com/siemens/jailhouse
commit: 607251b44397666a3cbbf859d784dccf20aba016
Purpose: Dual-licensing of inmate lib code
Maintained-by: Zephyr
Signed-off-by: Gustavo Lima Chaves <gustavo.lima.chaves@intel.com>
This adds CONFIG_EXECUTE_XOR_WRITE, which is enabled by default on
systems that support controlling whether a page can contain executable
code. This is also known as W^X[1].
Trying to add a memory domain with a page that is both executable and
writable, either for supervisor mode threads, or for user mode threads,
will result in a kernel panic.
There are few cases where a writable page should also be executable
(JIT compilers, which are most likely out of scope for Zephyr), so an
option is provided to disable the check.
Since the memory domain APIs are executed in supervisor mode, a
determined person could bypass these checks with ease. This is seen
more as a way to avoid people shooting themselves in the foot.
[1] https://en.wikipedia.org/wiki/W%5EX
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
We were unnecessarily pulling in headers which resulted in kernel.h
being pulled in, which is undesirable since arch/cpu.h pulls in
these headers.
Added integral type headers since we do need those.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
kernel.h depends on arch.h, and reverse dependencies need to be
removed. Define k_tid_t as some opaque pointer type so that arch.h
doesn't have to pull in kernel.h.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This header needs Zephyr's specific type definitions. It also
needs struct k_mem_partition and struct k_mem_domain, but they
are defined opaquely here instead of pulling in kernel.h (which
would create nasty dependency loops)
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Created structures and unions needed to enable the software to
access these tables.
Also updated the helper macros to ease the usage of the MMU page
tables.
JIRA: ZEP-2511
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
Some SOCs (e.g. STM32F0) can map the flash to address 0 and
the flash base address at the same time. Prevent writing to
duplicate flash address which stops the SOC.
Allow Cortex M SOCs to create their own vector table relocation
function.
Provide a relocation function for STM32F0x SOCs.
Fixes#3923
Signed-off-by: Bobby Noelte <b0661n0e17e@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
arg6 is treated as a memory constraint. If that memory
address was expressed as an operand to 'mov' in the generated
code as an offset from the stack pointer, then the 'push'
instruction immediately before it could end up causing memory 4
bytes off from what was intended being passed in as the 6th
argument.
Add ESP register to the clobber list to fix this issue.
Fixes issues observed with k_thread_create() passing in a
NULL argument list with CONFIG_DEBUG=y.
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>
These needed "memory" clobbers otherwise the compiler would do
unnecessary optimizations for parameters passed in as pointer
values.
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>
The compiler was complaining about impossible constraints since register
constraint was provided, but there are no general purpose registers left
available.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This wasn't working properly with CONFIG_APPLICATION_MEMORY enabled as
the sections weren't handled in the linker script.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
A quick look at "man syscall" shows that in Linux, all architectures
support at least 6 argument system calls, with a few supporting 7. We
can at least do 6 in Zephyr.
x86 port modified to use EBP register to carry the 6th system call
argument.
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>
- _arch_user_mode_enter() implemented
- _arch_is_user_context() implemented
- _new_thread() will honor K_USER option if passed in
- System call triggering macros implemented
- _thread_entry_wrapper moved and now looks for the next function to
call in EDI
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
- There's no point in building up "validity" (declared volatile for some
strange reason), just exit with false return value if any of the page
directory or page table checks don't come out as expected
- The function was returning the opposite value as its documentation
(0 on success, -EPERM on failure). Documentation updated.
- This function will only be used to verify buffers from user-space.
There's no need for a flags parameter, the only option that needs to
be passed in is whether the buffer has write permissions or not.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The byte ones are required for ns16550 uart driver which is
present on some arm socs. Add half-word ones for completeness.
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This was felt to be necessary at one point but actually isn't.
- When a thread is initialized to use a particular stack, calls will be
made to the MMU/MPU to restrict access to that stack to only that
thread. Once a stack is in use, it will not be generally readable even
if the buffer exists in application memory space.
- If a user thread wants to create a thread, we will need to have some
way to ensure that whatever stack buffer passed in is unused and
appropriate. Since unused stacks in application memory will be generally
accessible, we can just check that the calling thread to
k_thread_create() has access to the stack buffer passed in, it won't if
the stack is in use.
On ARM we had a linker definition for .stacks, but currently stacks are
just tagged with __noinit (which is fine).
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Previously, this was only done if an essential thread self-exited,
and was a runtime check that generated a kernel panic.
Now if any thread has k_thread_abort() called on it, and that thread
is essential to the system operation, this check is made. It is now
an assertion.
_NANO_ERR_INVALID_TASK_EXIT checks and printouts removed since this
is now an assertion.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
All system calls made from userspace which involve pointers to kernel
objects (including device drivers) will need to have those pointers
validated; userspace should never be able to crash the kernel by passing
it garbage.
The actual validation with _k_object_validate() will be in the system
call receiver code, which doesn't exist yet.
- CONFIG_USERSPACE introduced. We are somewhat far away from having an
end-to-end implementation, but at least need a Kconfig symbol to
guard the incoming code with. Formal documentation doesn't exist yet
either, but will appear later down the road once the implementation is
mostly finalized.
- In the memory region for RAM, the data section has been moved last,
past bss and noinit. This ensures that inserting generated tables
with addresses of kernel objects does not change the addresses of
those objects (which would make the table invalid)
- The DWARF debug information in the generated ELF binary is parsed to
fetch the locations of all kernel objects and pass this to gperf to
create a perfect hash table of their memory addresses.
- The generated gperf code doesn't know that we are exclusively working
with memory addresses and uses memory inefficently. A post-processing
script process_gperf.py adjusts the generated code before it is
compiled to work with pointer values directly and not strings
containing them.
- _k_object_init() calls inserted into the init functions for the set of
kernel object types we are going to support so far
Issue: ZEP-2187
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This patch fixes a couple of issues with the stack guard size and
properly constructs the STACK_ALIGN and STACK_ALIGN_SIZE definitions.
The ARM AAPCS requires that the stack pointers be 8 byte aligned. The
STACK_ALIGN_SIZE definition is meant to contain the stack pointer
alignment requirements. This is the required alignment at public API
boundaries (ie stack frames).
The STACK_ALIGN definition is the required alignment for the start
address for stack buffer storage. STACK_ALIGN is used to validate
the allocation sizes for stack buffers.
The MPU_GUARD_ALIGN_AND_SIZE definition is the minimum alignment and
size for the MPU. The minimum size and alignment just so happen to be
32 bytes for vanilla ARM MPU implementations.
When defining stack buffers, the stack guard alignment requirements
must be taken into consideration when allocating the stack memory.
The __align() must be filled in with either STACK_ALIGN_SIZE or the
align/size of the MPU stack guard. The align/size for the guard region
will be 0 when CONFIG_MPU_STACK_GUARD is not set, and 32 bytes when it
is.
The _ARCH_THREAD_STACK_XXXXXX APIs need to know the minimum alignment
requirements for the stack buffer memory and the stack guard size to
correctly allocate and reference the stack memory. This is reflected
in the macros with the use of the STACK_ALIGN definition and the
MPU_GUARD_ALIGN_AND_SIZE definition.
Signed-off-by: Andy Gross <andy.gross@linaro.org>
* apply STACK_GUARD_SIZE, no extra space will be added if
MPU_STACK_GUARD is disabled
* When ARC_STACK_CHECKING is enabled, MPU_STACK_GUARD will be
disabled
* add two new api: arc_core_mpu_default and arc_core_mpu_region
to configure mpu regions
* improve arc_core_mpu_enable and arc_core_mpu_disable
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* add arc mpu driver
* modify the corresponding kconfig and kbuild
* currently only em_starterkit 2.2's em7d configuration
has mpu feature (mpu version 2)
* as the minimum region size of arc mpu version 2 is 2048 bytes and
region size should be power of 2, the stack size of threads
(including main thread and idle thread) should be at least
2048 bytes and power of 2
* for mpu stack guard feature, a stack guard region of 2048 bytes
is generated. This brings more memory footprint
* For arc mpu version 3, the minimum region size is 32 bytes.
* the codes are tested by the mpu_stack_guard_test and stackprot
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
Fix misspellings in .h files missed during code reviews
and affecting generated API documentation
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
An abnormal crash was encountered in ARMv6-M SoCs that don't have flash
starting at 0. With Zephyr OS the reason for this crash is that, on
ARMv6-M the system requires an exception vector table at the 0 address.
We implement the relocate_vector_table function to move the vector table
code to address 0 on systems which don't have the start of code already
at 0.
[kumar.gala: reworderd commit message, tweaked how we check if we need
to copy vector table]
Signed-off-by: Xiaorui Hu <xiaorui.hu@linaro.org>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
The Xtensa port was the only one remaining to be converted to the new
way of connecting interrupts in Zephyr. Some things are still
unconverted, mainly the exception table, and this will be performed
another time.
Of note: _irq_priority_set() isn't called on _ARCH_IRQ_CONNECT(), since
IRQs can't change priority on Xtensa: while the architecture has the
concept of interrupt priority levels, each line has a fixed level and
can't be changed.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
This patch adjusts the ARM MPU implementation to be compliant to the
recent changes that introduced the opaque kernel data types.
Signed-off-by: Andy Gross <andy.gross@linaro.org>
This patch always defines the ARCH_THREAD_STACK_XXX macros/functions
regardless of the MPU_STACK_GUARD usage. Only use MPU_STACK_GUARD when
determining the minimum stack alignment.
Signed-off-by: Andy Gross <andy.gross@linaro.org>
The mimimum mpu size is 32 bytes, but requires mpu base address to be
aligned on 32 bytes to work. Define architecture thread macro when
MPU_STACK_GUARD config to allocate stack with 32 more bytes.
Signed-off-by: Michel Jaouen <michel.jaouen@st.com>
This patch adds the allow flash write CONFIG option to the ARM MPU
configuration in privileged mode.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@linaro.org>
Signed-off-by: Michael Scott <michael.scott@linaro.org>
Signed-off-by: David Brown <david.brown@linaro.org>
This patch adds the allow flash write CONFIG option to the NXP MPU
configuration in privileged mode.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@linaro.org>
Signed-off-by: David Brown <david.brown@linaro.org>
This is a simpler memory arrangement; RAM will start with
app data, and everything after it is either kernel data or
unclaimed memory reserved for the kernel's use.
New linker variables are also implemented here.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Kernel data size shifts in between linker passes due to the addition
of the page tables. We would like application memory bounds to
remain fixed so that we can program the MMU permissions for it
at build time.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Page faults will additionally dump out some interesting
page directory and page table flags for the faulting
memory address.
Intended to help determine whether the page tables have been
configured incorrectly as we enable memory protection features.
This only happens if CONFIG_EXCEPTION_DEBUG is turned on.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Historically, stacks were just character buffers and could be treated
as such if the user wanted to look inside the stack data, and also
declared as an array of the desired stack size.
This is no longer the case. Certain architectures will create a memory
region much larger to account for MPU/MMU guard pages. Unfortunately,
the kernel interfaces treat both the declared stack, and the valid
stack buffer within it as the same char * data type, even though these
absolutely cannot be used interchangeably.
We introduce an opaque k_thread_stack_t which gets instantiated by
K_THREAD_STACK_DECLARE(), this is no longer treated by the compiler
as a character pointer, even though it really is.
To access the real stack buffer within, the result of
K_THREAD_STACK_BUFFER() can be used, which will return a char * type.
This should catch a bunch of programming mistakes at build time:
- Declaring a character array outside of K_THREAD_STACK_DECLARE() and
passing it to K_THREAD_CREATE
- Directly examining the stack created by K_THREAD_STACK_DECLARE()
which is not actually the memory desired and may trigger a CPU
exception
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
