ARC_MPU_VER 2 has a strong requirement in
* size, must be >= 2048 bytes and power of 2
* start address must be aligned to size
It may bring a big waste of memory.
On the other hand, GEN_PRIV_STACK is used for ARC_MPU_VER 2,
it conflicts with MPU_STACK_GUARD.
So considering the limmitations, remove MPU_STACK_GUARD for
ARC_MPU_VER 2
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
drop the original C macro based allocation of privilged stack as
it may cause the waste of memory for ARC MPUv2.
now use the way of GEN_PRIV_STACK to generate privilege stack as
other archs did, e.g. ARM.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
the old codes just work for single core, we need to consider
the case of SMP.
In SMP, it's not easy to get current thread of current cpu in
assembly, so we'd better do it in C.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* update comments to match latest codes
* add extra comments for some assembly, macros
* use macro to replace duplcated codes
* remove unused codes, lables, symobols
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
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>
These are not part of the generic kernel to
architecture interface, rename appropriately to
reflect they are ARC-specific.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
* the old codes may not save the caller saved regs correctly,
e.g. r7- r12. Because the sys call entry is called in the form
of static inline function. The compiler optimizations may not save
all the caller saved regs.
* new codes use the irq stack frame as the sys call frame and gurantee
all the called saved regs are pushed and popped correctly.
* the side effect of new codes are more stack operations and a little
overhead.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* it's based on ARC SecureShield
* add basic secure service in arch/arc/core/secureshield
* necesssary changes in arch level
* thread switch
* irq/exception handling
* initialization
* add secure time support
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
KFLAG instruction might affect multiple flags in STATUS32 register
and so when we need just AE-bit to be reset we need first read current
state of STATUS32, then change our bit and set STATUS32 again.
Otherwise critical flags including stack checking, unaligned access etc
will be dropped for good.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
* here use new style z_arch_switch,i.e. CONFIG_USE_SWITCH
to replace old swap mechnism.
* it's also required by SMP support
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
Rename reserved function names in arch/ subdirectory. The Python
script gen_priv_stacks.py was updated to follow the 'z_' prefix
naming.
Signed-off-by: Patrik Flykt <patrik.flykt@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 fake exception return is used to jump to user mode.
So the init status of user thread is in exception mode.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
The benchmark application timing_info needs certain hooks to be
present in the kernel to get the accurate measurements. This
patch adds these hook at all the required locations.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
* the original stack check codes have no consideration
for userspace case. This will wrong cause possible stack
check exception.
* this commit refactors the arc stack check support to
support the usperspace.
* this commit fixes#7885. All the failed tests in #7885
are run again to verify this commit. The test results are ok
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* blink, fp should not be always cleared
* clean up code format
* use a better way to save and restore ER_SEC_STAT
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
The new thread stack layout is as follow:
|---------------------|
| user stack |
|---------------------|
| stack guard (opt.) |
|---------------------|
| privilege stack |
-----------------------
For MPUv2
* user stack is aligned to the power of 2 of user stack size
* the stack guard is 2048 bytes
* the default size of privileg stack is 256 bytes.
For user thread, the following MPU regions are needded
* one region for user stack, no need of stack guard for user stack
* one region for stack guard when stack guard is enbaled
* regions for memory domain.
For kernel thread, the stack guard region will be at the top, adn
The user stack and privilege stack will be merged.
MPUv3 is the same as V2's layout, except no need of power of 2
alignment.
* reimplement the user mode enter function. Now it's possible for
kernel thread to drop privileg to user thread.
* add a separate entry for user thread
* bug fixes in the cleanup of regs when go to user mode
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
scrub all the regs of kernel context before returnning to userspace.
For sys call, ro is not cleared as it's a return value of sys call.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
Enable us bit to check user mode more efficienly.
US is read as zero in user mode. This will allow use mode sleep
instructions, and it enables a form of denial-of-service attack
by putting the processor in sleep mode, but since interrupt
level/mask can't be set from user space that's not worse than
executing a loop without yielding.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
* add the implementation of syscall
* based on 'trap_s' intruction, id = 3
* add the privilege stack
* the privilege stack is allocted with thread stack
* for the kernel thread, the privilege stack is also a
part of thread stack, the start of stack can be configured
as stack guard
* for the user thread, no stack guard, when the user stack is
overflow, it will fall into kernel memory area which requires
kernel privilege, privilege violation will be raised
* modify the linker template and add MPU_ADDR_ALIGN
* add user space corresponding codes in mpu
* the user sp aux reg will be part of thread context
* When user thread is interruptted for the 1st time, the context is
saved in user stack (U bit of IRQ_CTLR is set to 1). When nest
interrupt comes, the context is saved in thread's privilege stack
* the arc_mpu_regions.c is moved to board folder, as it's board
specific
* the above codes have been tested through tests/kernel/mem_protect/
userspace for MPU version 2
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
