Including signal.h would cause several ports to fail on build,
because it would end up including AK/Platform.h through these
mcontext headers. This is problematic because AK/Platform.h defines
several macros with very common names, such as `NAKED` (breaks radare2),
and `NO_SANITIZE_ADDRESS` and `ALWAYS_INLINE` (breaks ruby).
This adds some new buffers to the `FPUState` struct, which contains
enough space for the `xsave` instruction to run. This instruction writes
the upper part of the x86 SIMD registers (YMM0-15) to a seperate
256-byte area, as well as an "xsave header" describing the region.
If the underlying processor supports AVX, the `fxsave` instruction is no
longer used, as `xsave` itself implictly saves all of the SSE and x87
registers.
Co-authored-by: Leon Albrecht <leon.a@serenityos.org>
The code in Spinlock.h has no architectural specific logic, thus can be
moved to the Arch directory. This contains no functional change.
Also add the Spinlock.cpp file for aarch64 which contains stubs for the
lock and unlock functions.
I've noticed that the KVM hypervisor vendor ID string contained null
terminators in the serialized JSON string in /proc/cpuinfo - let's avoid
that, and err on the side of caution and strip them from all strings
built from CPUID register values. They may not be fixed width after all.
Let's use terminology from the the Intel manual to avoid confusion.
Also add `_string` suffixes to better distinguish the numeric values
from the string values.
We're now able to detect all the regular CPUID feature flags from
ECX/EDX for EAX=1 :^)
None of the new ones are being used for anything yet, but they will show
up in /proc/cpuinfo and subsequently lscpu and SystemMonitor.
Note that I replaced the periods from the SSE 4.1 and 4.2 instructions
with underscores, which matches the internal enum names, Linux's
/proc/cpuinfo and the general pattern of replacing special characters
with underscores to limit feature names to [a-z0-9_].
The enum member stringification has been moved to a new function for
better re-usability and to avoid cluttering up Processor.cpp.
This will make it possible to add many, many more CPU features - more
than the current limit 32 and later limit of 64 if we stick with an enum
class to be specific :^)
Checks of ECX go before EDX, and the bit indices are now ordered
properly. Additionally, handling of the EDX[11] bit has been moved into
a lambda function to keep the series of if statements neatly together.
All of this makes it *a lot* easier to follow along and compare the
implementation to the tables in the Intel manual, e.g. to find missing
checks.
As there is no need for a Prekernel on aarch64, the Prekernel code was
moved into Kernel itself. The functionality remains the same.
SERENITY_KERNEL_AND_INITRD in run.sh specifies a kernel and an inital
ramdisk to be used by the emulator. This is needed because aarch64
does not need a Prekernel and the other ones do.
These are not technically required, since the Thread constructor
already sets these, but they are set on i686, so let's try and keep
consistent behaviour between the different archs.
The AP boot code was partially adapted to build on x86_64 but didn't
properly jump into 64 bit mode. Furthermore, the APIC code was still
using 32 bit pointers.
Fixes#12662
Function-local `static constexpr` variables can be `constexpr`. This
can reduce memory consumption, binary size, and offer additional
compiler optimizations.
These changes result in a stripped x86_64 kernel binary size reduction
of 592 bytes.
Even if the PIC was disabled it can still generate noise (spurious IRQs)
so we need to register two handlers for handling such cases.
Also, we declare interrupt service routine offset 0x20 to 0x2f as
reserved, so when the PIC is disabled, we can handle spurious IRQs from
the PIC at separate handlers.
Move this architecture-specific sanity check (IOPL must be 0) out of
Scheduler and into the x86 enter_thread_context(). Also do this for
every thread and not just userspace ones.
It was annoyingly hard to spot these when we were using them with
different amounts of qualification everywhere.
This patch uses Thread::State::Foo everywhere instead of Thread::Foo
or just Foo.
Signal dispatch is already taken care of elsewhere, so there appears to
be no need for the hack in enter_current().
This also allows us to remove the Thread::m_in_block flag, simplifying
thread blocking logic somewhat.
Verified with the original repro for #4336 which this was meant to fix.
Ideally the x86 fault handler would only do x86 specific things and
delegate the rest of the work to MemoryManager. This patch moves some of
the address checks to a more generic place.
This allows us to enable Write-Combine on e.g. framebuffers,
significantly improving performance on bare metal.
To keep things simple we right now only use one of up to three bits
(bit 7 in the PTE), which maps to the PA4 entry in the PAT MSR, which
we set to the Write-Combine mode on each CPU at boot time.
If there's nobody listening for the crash signal, fall back to the
normal crash path where we get some debug output about what happened.
Thanks to Idan for suggesting the fix.
Since the inline capacity of the Vector return type was not specified
explicitly, the vector was automatically copied to a 0-length inline
capacity one, essentially eliminating the optimization.
