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>
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>
This commit exposes k_mem_partition_attr_t outside User Mode, so
we can use struct k_mem_partition for defining memory partitions
outside the scope of user space (for example, to describe thread
stack guards or no-cacheable MPU regions). A requirement is that
the Zephyr build supports Memory protection. To signify this, a
new hidden, all-architecture Kconfig symbol is defined (MPU). In
the wake of exposing k_mem_partition_attr_t, the commit exposes
the MPU architecture-specific access permission attribute macros
outside the User space context (for all ARCHs), so they can be
used in a more generic way.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
There were many platforms where this function was doing nothing. Just
merging its functionality with _PrepC function.
Signed-off-by: Flavio Ceolin <flavio.ceolin@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>
Always compare unsigned interger type with another unsigned
integer type. Currently in nios2, posix, riscv32, x86 and xtensa
we were comparing the _kernel.nested variable with a signed
interger type. Fixed this violation.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@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>
Any word started with underscore followed by and uppercase letter or a
second underscore is a reserved word according with C99.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
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>
Bitwise operators should be used only with unsigned integer operands
because the result os bitwise operations on signed integers are
implementation-defined.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Setting bit CR0.WP (bit 16) will inhibit supervisor threads from
writing to RO pages. It's a necessary flag to be set, and the constant
name CR0_PAGING_ENABLE didn't reflect the fact that the 16th bit was
being set.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
In order to mitigate against Spectre V4, add an option that will, at
boot time, verify if the CPU supports the SPEC_CTRL MSR; if so, it'll
attempt to disable the feature.
More information can be found in chapter 4 (Speculative Store Bypass
Mitigation) of the "Speculative Execution Side Channel Mitigations"
document, version 2, published by Intel: https://goo.gl/nocTcj
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
gdb_server was removed in commit 0f669132a0 ("kernel: remove
gdb_server"), but still has a testcase that sets CONFIG_GDB_SERVER=y,
and some code in arch/x86/debug.
Remove the leftover parts. This also gets gets rid of undefined
references to the CONFIG_GDB_SERVER symbol.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Rename _MsrRead() and _MsrWrite() to _x86_msr_read() and
_x86_msr_write() respectively.
Given that these functions are essentially implemented in assembly.
make them static inline. They can be inlined by the compiler quite
well, most of the time incurring in space savings due to better
handling of the cobbled registers.
Also simplifies the inline assembly, using constraints instead of
moving registers ourselves. Should shave off a few bytes from code
using these functions.
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
If we enable CONFIG_DEBUG_INFO, then we need to fixup the stack
on thread entry so that the EFLAGS value in the EBP slot doesn't
confuse the debugger or any runtime stack unwinding code.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This feature is X86 only and is not used or being tested. It is legacy
feature and no one can prove it actually works. Remove it until we have
proper documentation and samples and multi architecture support.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This feature is X86 only and is not used or being tested. It is legacy
feature and no one can prove it actually works. Remove it until we have
proper documentation and samples and multi architecture support.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Rename the nano_internal.h to kernel_internal.h and modify the
header file name accordingly wherever it is used.
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Besides the fact that we did not have that for the current supported
boards, that makes sense for this new, virtualized mode, that is meant
to be run on top of full-fledged x86 64 CPUs.
By having xAPIC mode access only, Jailhouse has to intercept those MMIO
reads and writes, in order to examine what they do and arbitrate if it's
safe or not (e.g. not all values are accepted to ICR register). This
means that we can't run away from having a VM-exit event for each and
every access to APIC memory region and this impacts the latency the
guest OS observes over bare metal a lot.
When in x2APIC mode, Jailhouse does not require VM-exits for MSR
accesses other that writes to the ICR register, so the latency the guest
observes is reduced to almost zero.
Here are some outputs of the the command line
$ sudo ./tools/jailhouse cell stats tiny-demo
on a Jailhouse's root cell console, for one of the Zephyr demos using
LOAPIC timers, left for a couple of seconds:
Statistics for tiny-demo cell (x2APIC root, x2APIC inmate)
COUNTER SUM PER SEC
vmexits_total 7 0
vmexits_management 3 0
vmexits_cr 2 0
vmexits_cpuid 1 0
vmexits_msr 1 0
vmexits_exception 0 0
vmexits_hypercall 0 0
vmexits_mmio 0 0
vmexits_pio 0 0
vmexits_xapic 0 0
vmexits_xsetbv 0 0
Statistics for tiny-demo cell (xAPIC root, xAPIC inmate)
COUNTER SUM PER SEC
vmexits_total 4087 40
vmexits_xapic 4080 40
vmexits_management 3 0
vmexits_cr 2 0
vmexits_cpuid 1 0
vmexits_msr 1 0
vmexits_exception 0 0
vmexits_hypercall 0 0
vmexits_mmio 0 0
vmexits_pio 0 0
vmexits_xsetbv 0 0
Statistics for tiny-demo cell (xAPIC root, x2APIC inmate)
COUNTER SUM PER SEC
vmexits_total 4087 40
vmexits_msr 4080 40
vmexits_management 3 0
vmexits_cr 2 0
vmexits_cpuid 1 0
vmexits_exception 0 0
vmexits_hypercall 0 0
vmexits_mmio 0 0
vmexits_pio 0 0
vmexits_xapic 0 0
vmexits_xsetbv 0 0
See that under x2APIC mode on both Jailhouse/root-cell and guest, the
interruptions from the hypervisor are minimal. That is not the case when
Jailhouse is on xAPIC mode, though. Note also that, as a plus, x2APIC
accesses on the guest will map to xAPIC MMIO on the hypervisor just
fine.
Signed-off-by: Gustavo Lima Chaves <gustavo.lima.chaves@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 our Zephyr tools don't like seeing UTF-8 characters, as reported in
issue #4131) so a quick scan and replace for UTF-8 characters in .rst,
.h, and Kconfig files using "file --mime-encoding" (excluding the /ext
folders) finds these files to tweak.
Signed-off-by: David B. Kinder <david.b.kinder@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>
Helper macros to ease the usage of the MMU page table structures.
Added Macros to get Page table address and Page Table Entry
values.
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
The CPU first checks the page directory entry for write
or user permissions on a particular page before looking
at the page table entry.
If a region configured all pages to be non user accessible,
and this was changed for a page within it to be accessible,
the PDE would not be updated and any access would still
return a page fault.
The least amount of runtime logic to deal with this is to
indicate at build time that some pages within a region may
be marked writable or user accessible at runtime, and to
pre-set the flags in the page directory entry accordingly.
The driving need for this is the region configuration for
kernel memory, which will have user permissions set at
runtime for stacks and user-configured memory domains.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Subsequent patches will set this guard page as unmapped,
triggering a page fault on access. If this is due to
stack overflow, a double fault will be triggered,
which we are now capable of handling with a switch to
a know good stack.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
We now create a special IA hardware task for handling
double faults. This has a known good stack so that if
the kernel tries to push stack data onto an unmapped page,
we don't triple-fault and reset the system.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This has one use-case: configuring the double-fault #DF
exception handler to do an IA task switch to a special
IA task with a known good stack, such that we can dump
diagnostic information and then panic.
Will be used for stack overflow detection in kernel mode,
as otherwise the CPU will triple-fault and reset.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
A user space buffer must be validated before required operation
can proceed. This API will check the current MMU
configuration to determine if the buffer held by the user is valid.
Jira: ZEP-2326
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
This breaks too easily, for example if &some_linker_variable
is used. The names don't matter at all, use preprocessor
__COUNTER__.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
In crt0.S the MMU is initialized. It uses the statically build
page tables. Here 32-bit paging scheme is used, thereby each page
table entry maps to a 4KB page. The valid regions of the memory are
specified by SOC specific file(soc.c).
JIRA: ZEP-2099
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
Macro is used to create a structure to specify the boot time
page table configuration. Needed by the gen_mmu.py script to generate
the actual page tables.
Linker script is needed for the following:
1. To place the MMU page tables at 4KByte boundary.
2. To keep the configuration structure created by
the Macro(mentioned above).
Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>
None of this is currently necessary, the spurious interrupt
stubs and exception entry code is included in the binary just
fine. To make matters worse, some data referenced lives in the
.intList section which is completely stripped out of the binary.
If in the future we find certain essential functions are being
garbage collected when they should not be, the proper way to
mitigate this is with KEEP() directives in the linker script.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This was more or less transplanted from old Viper codebase (Zephyr's
ancestor which supported paging) and adapted to current coding style.
Change-Id: I203e631f1dcd5f2fb4e9a2fa9339fc7521c7962d
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Historically, space for struct k_thread was always carved out of the
thread's stack region. However, we want more control on where this data
will reside; in memory protection scenarios the stack may only be used
for actual stack data and nothing else.
On some platforms (particularly ARM), including kernel_arch_data.h from
the toplevel kernel.h exposes intractable circular dependency issues.
We create a new per-arch header "kernel_arch_thread.h" with very limited
scope; it only defines the three data structures necessary to instantiate
the arch-specific bits of a struct k_thread.
Change-Id: I3a55b4ed4270512e58cf671f327bb033ad7f4a4f
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types. There are few places we dont convert over to the new
types because of compatiability with ext/HALs or for ease of transition
at this point. Fixup a few of the PRI formatters so we build with newlib.
Jira: ZEP-2051
Change-Id: I7d2d3697cad04f20aaa8f6e77228f502cd9c8286
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
This is a start to move away from the C99 {u}int{8,16,32,64}_t types to
Zephyr defined u{8,16,32,64}_t and s{8,16,32,64}_t. This allows Zephyr
to define the sized types in a consistent manor across all the
architectures we support and not conflict with what various compilers
and libc might do with regards to the C99 types.
We introduce <zephyr/types.h> as part of this and have it include
<stdint.h> for now until we transition all the code away from the C99
types.
We go with u{8,16,32,64}_t and s{8,16,32,64}_t as there are some
existing variables defined u8 & u16 as well as to be consistent with
Zephyr naming conventions.
Jira: ZEP-2051
Change-Id: I451fed0623b029d65866622e478225dfab2c0ca8
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
CONFIG_* usually come from Kconfig, rename variables that are locally
defined to avoid confusion about where they are set.
Change-Id: I402713e6f852907e75be4bc2b916a7d15dd5649c
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The K_<thread option> flags/options avaialble to users were hidden in
the kernel private header files: move them to include/kernel.h to
publicize them.
Also, to avoid any future confusion, rename the k_thread.execution_flags
field to user_options.
Change-Id: I65a6fd5e9e78d4ccf783f3304b607a1e6956aeac
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
They are internal states, not user-facing.
Also prepend an underscore since they are kernel internal symbols.
Change-Id: I53740e0d04a796ba1ccc409b5809438cdb189332
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.
Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.
Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file. Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.
Jira: ZEP-1457
Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
