With the introduction of Z_MEM_*_ADDR for physical<->virtual
address translation, there is no need to have x86 specific
versions.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
All arch_ APIs and macros are implemented, and the page fault
handling code will call into the core kernel.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
All arch_ APIs and macros are implemented, and the page fault
handling code will call into the core kernel.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The page table implementation requires conversion between virtual
and physical addresses when creating and walking page tables. Add
a phys_addr() and virt_addr() functions instead of hard-casting
these values, plus a macro for doing the same in ASM code.
Currently, all pages are identity mapped so VIRT_OFFSET = 0, but
this will now still work if they are not the same.
ASM language was also updated for 32-bit. Comments were left in
64-bit, as long mode semantics don't allow use of Z_X86_PHYS_ADDR
macro; this can be revisited later.
Signed-off-by: Andrew Boie <andrew.p.boie@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>
We no longer plan to support a split address space with
the kernel in high memory and per-process address spaces.
Because of this, we can simplify some things. System RAM
is now always identity mapped at boot.
We no longer require any virtual-to-physical translation
for page tables, and can remove the dual-mapping logic
from the page table generation script since we won't need
to transition the instruction point off of physical
addresses.
CONFIG_KERNEL_VM_BASE and CONFIG_KERNEL_VM_LIMIT
have been removed. The kernel's address space always
starts at CONFIG_SRAM_BASE_ADDRESS, of a fixed size
specified by CONFIG_KERNEL_VM_SIZE.
Driver MMIOs and other uses of k_mem_map() are still
virtually mapped, and the later introduction of demand
paging will result in only a subset of system RAM being
a fixed identity mapping instead of all of it.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The x86 paging code has been rewritten to support another paging mode
and non-identity virtual mappings.
- Paging code now uses an array of paging level characteristics and
walks tables using for loops. This is opposed to having different
functions for every paging level and lots of #ifdefs. The code is
now more concise and adding new paging modes should be trivial.
- We now support 32-bit, PAE, and IA-32e page tables.
- The page tables created by gen_mmu.py are now installed at early
boot. There are no longer separate "flat" page tables. These tables
are mutable at any time.
- The x86_mmu code now has a private header. Many definitions that did
not need to be in public scope have been moved out of mmustructs.h
and either placed in the C file or in the private header.
- Improvements to dumping page table information, with the physical
mapping and flags all shown
- arch_mem_map() implemented
- x86 userspace/memory domain code ported to use the new
infrastructure.
- add logic for physical -> virtual instruction pointer transition,
including cleaning up identity mappings after this takes place.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
If we get a page fault in early boot context, before
main thread is started, page faults were being
incorrectly reported as stack overflows.
z_x86_check_stack_bounds() needs to consider the
interrupt stack as the correct stack for this context.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This helps distingush between fatal errors if logging isn't
enabled.
As detailed in comments, pass a reason code which controls
the QEMU process' return value.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
x86_64's __resume path 'poisons' the incoming thread's
saved RIP value with a special 0xB9 value, to catch
re-use of thread objects across CPUs in SMP. Add a check
and printout for this when handling fatal errors, and
treat as a kernel panic.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
If KPTI is not enabled, the current value of CR3 is the correct
page tables when the exception happened in all cases.
If KPTI is enabled, and the excepting thread was in user mode,
then a page table switch happened and the current value of CR3
is not the page tables when the fault happened. Get it out of the
thread object instead.
Fixes two problems:
- Divergent exception loop if we crash when _current is a dummy
thread or its page table pointer stored in the thread object is
NULL or uninitialized
- Printing the wrong CR3 value on exceptions from user mode in
the register dump
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This operation is formally defined as rounding down a potential
stack pointer value to meet CPU and ABI requirments.
This was previously defined ad-hoc as STACK_ROUND_DOWN().
A new architecture constant ARCH_STACK_PTR_ALIGN is added.
Z_STACK_PTR_ALIGN() is defined in terms of it. This used to
be inconsistently specified as STACK_ALIGN or STACK_PTR_ALIGN;
in the latter case, STACK_ALIGN meant something else, typically
a required alignment for the base of a stack buffer.
STACK_ROUND_UP() only used in practice by Risc-V, delete
elsewhere.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The set of interrupt stacks is now expressed as an array. We
also define the idle threads and their associated stacks this
way. This allows for iteration in cases where we have multiple
CPUs.
There is now a centralized declaration in kernel_internal.h.
On uniprocessor systems, z_interrupt_stacks has one element
and can be used in the same way as _interrupt_stack.
The IRQ stack for CPU 0 is now set in init.c instead of in
arch code.
The extern definition of the main thread stack is now removed,
this doesn't need to be in a header.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We use a fixed value of 32 as the way interrupts/exceptions
are setup in x86_64's locore.S do not lend themselves to
Kconfig configuration of the vector to use.
HW-based kernel oops is now permanently on, there's no reason
to make it optional that I can see.
Default vectors for IPI and irq offload adjusted to not
collide.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
z_x86_thread_page_tables_get() now works for both user
and supervisor threads, returning the kernel page tables
in the latter case. This API has been up-leveled to
a common header.
The per-thread privilege elevation stack initial stack
pointer, and the per-thread page table locations are no
longer computed from other values, and instead are stored
in thread->arch.
A problem where the wrong page tables were dumped out
on certain kinds of page faults has been fixed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Add two new non-static APIs for dumping out the
page table entries for a specified memory address,
and move to the main MMU code. Has debugging uses
when trying to figure out why memory domains are not
set up correctly.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Runtime stack traces (at least as currently implemented)
don't work on x86_64 normally as RBP is treated as a general-
purpose register. Depend on CONFIG_NO_OPTIMIZATIONS to enable
this on 64-bit.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
qemu_x86_64 will exit the emulator on a fatal system error,
like qemu_x86 already does.
Improves CI times when tests fail since sanitycheck will not
need to wait for the timeout to expire.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We now dump more information for less common cases,
and this is now centralized code for 32-bit/64-bit.
All of this code is now correctly wrapped around
CONFIG_EXCEPTION_DEBUG. Some cruft and unused defines
removed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.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>
Some code for unwinding stacks and z_x86_fatal_error()
now in a common C file, suitable for both modes.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Create source directory for IA32-subarch specific files, and move
qualifying files to that subdirectory.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
It's relatively hard to figure out what thread a crash happens in
from the crash dump. E.g, it's usually not immediately possible to
find it out from linker map due to the fact that static symbols are
not there (https://sourceware.org/bugzilla/show_bug.cgi?id=16566).
So, try to do it as easy if possible, by just printing thread name
in a dump, if thread names are enabled at all.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
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>
MISRA defines a serie of essential types, boolean, signed/unsigned
integers, float, ... and operations must respect these essential types.
MISRA-C rule 10.1
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 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>
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>
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>
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>
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>
