We need a copy of the flags field for ever PTE we are
updating, we can't just keep OR-ing in the address
field.
Fixes issues seen when setting flags for memory regions
larger than a page.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
During speculative execution, non-present pages are treated
as valid, which may expose their contents through side
channels.
Any non-present PTE will now have its address bits zeroed,
such that any speculative reads to them will go to the NULL
page.
The expected hit on performance is so minor that this is
enabled at all times.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Retpolines were never completely implemented, even on x86.
Move this particular Kconfig to only concern itself with
the assembly code, and don't default it on ever since we
prefer SSBD instead.
We can restore the common kernel-wide CONFIG_RETPOLINE once
we have an end-to-end implementation.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
PAE page tables (the only kind we support) have 512
entries per page directory, not 1024.
Fixes: #13838
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>
If the faulting context is in user mode, then we are
not on the same stack due to HW-level stack switching
on privilege elevation, and the faulting ESP is on
the stack itself.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The code did not consider privilege level stack switches.
We have the original stack pointer in the NANO_ESF,
just use that.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We now have a dedicated function to test whether
a memory region is withing the boundary of the
faulting context's stack buffer.
We use this to determine whether a page or double fault
was due to ESP being outside the bounds of the stack,
as well as when unwinding stack frames to print debug
output.
Fixes two issues:
- Stack overflows in user mode being incorrectly reported
as just page fault exceptions
- Exceptions that occur when unwinding corrupted stacks
The type of fault which triggered the stack overflow
logic (double or page fault) is now always shown.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The code wasn't checking if the memory address to check
corresponded to a non-present page directory pointer
table entry.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Upon hard/soft irq or exception entry/exit, handle transitions
off or onto the trampoline stack, which is the only stack that
can be used on the kernel side when the shadow page table
is active. We swap page tables when on this stack.
Adjustments to page tables are now as follows:
- Any adjustments for stack memory access now are always done
to the user page tables
- Any adjustments for memory domains are now always done to
the user page tables
- With KPTI, resetting a page now clears the present bit
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
In the event of a double fault, we do a HW task switch to
a special _df_tss hardware task which resets the stack
pointer to the interrupt stack and otherwise restores
the main hardware task to a runnable state so that
_df_handler_bottom() can run.
However, we need to make sure that _df_handler_bottom()
runs with interrupts locked, otherwise another IRQ could
corrupt the interrupt stack resulting in undefined
behavior.
We have very little stack space to work with in this
context, just zero it. It's a fatal error for the thread
in any event.
Fixes: #7291
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit changes the names of SYS_POWER_DEEP_SLEEP* Kconfig
options in order to match SYS_POWER_LOW_POWER_STATE* naming
scheme.
Signed-off-by: Piotr Zięcik <piotr.ziecik@nordicsemi.no>
At boot, user threads were being granted access to the entire
app shared memory section. This is incorrect; user threads should
have no access until they are added to a memory domain, which
may contain partitions defined within it.
Change from MMU_ENTRY_USER (which grants permission at boot)
to MMU_ENTRY_RUNTIME_USER (which indicates that the pages may
be granted to user mode at runtime, but not at boot).
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We want a _Swap() variant that can atomically release/restore a
spinlock state in addition to the legacy irqlock. The function as it
was is now named "_Swap_irqlock()", while _Swap() now refers to a
spinlock and takes two arguments. The former will be going away once
existing users (not that many! Swap() is an internal API, and the
long port away from legacy irqlocking is going to be happening mostly
in drivers) are ported to spinlocks.
Obviously on uniprocessor setups, these produce identical code. But
SMP requires that the correct API be used to maintain the global lock.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
This was never a long-term solution, more of a gross hack
to get test cases working until we could figure out a good
end-to-end solution for memory domains that generated
appropriate linker sections. Now that we have this with
the app shared memory feature, and have converted all tests
to remove it, delete this feature.
To date all userspace APIs have been tagged as 'experimental'
which sidesteps deprecation policies.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This diverges from policy for all of our other arches
and C libraries. Global access to the malloc arena
may not be desirable.
Forthcoming patch will expose, for all C libraries, a
k_mem_partition with the malloc arena which can be
added to domains as desired.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is a separate data section which needs to be copied into
RAM.
Most arches just use the kernel's _data_copy(), but x86 has its
own optimized copying code.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
PAE tables introduce the NX bit which is very desirable
from a security perspetive, back in 1995.
PAE tables are larger, but we are not targeting x86 memory
protection for RAM constrained devices.
Remove the old style 32-bit tables to make the x86 port
easier to maintain.
Renamed some verbosely named data structures, and fixed
incorrect number of entries for the page directory
pointer table.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This patch adds all the required hooks needed in the kernel to
get the coverage reports from x86 SoCs.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
The operation was shifiting bit using a signed constant in the left
operand. Use BIT macro to do it properly.
MISRA-C rule 12.2
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
In C90 was introduced function prototype, that allows argument types
to be checked against parameter types, though it is not necessary
specify names for the parameters. MISRA-C requires names for function
prototype parameters, it claims that names can provide useful
information regarding the function interface.
MISRA-C rule 8.2
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
When __ASSERT is not enabled there is an attribution to the variable
total_partitions and it is never used.
MISRA-C rule 2.2
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
There is a function called _thread_entry defined in
lib/thread_entry.c. Just changing name to fix MISRA-C violation.
MISRA-C rule 5.8
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Previously, this was only built if CONFIG_EXCEPTION_DEBUG
was enabled, but CONFIG_USERSPACE needs it too for validating
strings sent in from user mode.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
If dynamic interrupts are enabled, a set of trampoline stubs
are generated which transfer control to a common dynamic
interrupt handler function, which then looks up the proper
handler and parameter and then executes the interrupt.
Based on the prior x86 dynamic interrupt implementation which
was removed from the kernel some time ago, and adapted to
changes in the common interrupt handling code, build system,
and IDT generation tools.
An alternative approach could be to read the currently executing
vector out of the APIC, but this is a much slower operation.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
struct k_thread already has a pointer type k_tid_t, there is no need for
this definition to tcs.
Less symbols/names make the code cleaner and more readable.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Instead of checking every time we hit the low-level context switch
path to see if the new thread has a "partner" with which it needs to
share time, just run the slice timer always and reset it from the
scheduler at the points where it has already decided a switch needs to
happen. In TICKLESS_KERNEL situations, we pay the cost of extra timer
interrupts at ~10Hz or whatever, which is low (note also that this
kind of regular wakeup architecture is required on SMP anyway so the
scheduler can "notice" threads scheduled by other CPUs). Advantages:
1. Much simpler logic. Significantly smaller code. No variance or
dependence on tickless modes or timer driver (beyond setting a
simple timeout).
2. No arch-specific assembly integration with _Swap() needed
3. Better performance on many workloads, as the accounting now happens
at most once per timer interrupt (~5 Hz) and true rescheduling and
not on every unrelated context switch and interrupt return.
4. It's SMP-safe. The previous scheme kept the slice ticks as a
global variable, which was an unnoticed bug.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
MISRA-C requires that all declarations of a specific function, or
object, use the same names and type qualifiers.
MISRA-C rule 8.3
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Under GNU C, sizeof(void) = 1. This commit merely makes it explicit u8.
Pointer arithmetics over void types is:
* A GNU C extension
* Not supported by Clang
* Illegal across all ISO C standards
See also: https://gcc.gnu.org/onlinedocs/gcc/Pointer-Arith.html
Signed-off-by: Mark Ruvald Pedersen <mped@oticon.com>
Added LOG_PANIC to fault handlers to ensure that log is flush and
logger processes messages in a blocking way in fault handler.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
_k_syscall_table is an array of function pointers and is declared as
such in C sources, this makes it an STT_OBJECT[0] in the symbol
table. But when the same symbol is declared in assembly, it is
declared to be a function, which would make the symbol an STT_FUNC.
When linking with LTO this type inconsistency results in the warning:
real-ld: Warning: type of symbol `_k_syscall_table' changed from 2 to
1 in /tmp/cc84ofK0.ltrans8.ltrans.o
To fix this warning we declare the table with GDATA instead of GTEXT,
which will change the type from 'function' to 'object'.
[0]
https://docs.oracle.com/cd/E19455-01/816-0559/chapter6-79797/index.html
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
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>
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>
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>
