We add a prctl option which would be called once after the dynamic
loader has finished to do text relocations before calling the actual
program entry point.
This change makes it much more obvious when we are allowed to change
a region protection access from being writable to executable.
The dynamic loader should be able to do this, but after a certain point
it is obvious that such mechanism should be disabled.
The following command was used to clang-format these files:
clang-format-18 -i $(find . \
-not \( -path "./\.*" -prune \) \
-not \( -path "./Base/*" -prune \) \
-not \( -path "./Build/*" -prune \) \
-not \( -path "./Toolchain/*" -prune \) \
-not \( -path "./Ports/*" -prune \) \
-type f -name "*.cpp" -o -name "*.mm" -o -name "*.h")
There are a couple of weird cases where clang-format now thinks that a
pointer access in an initializer list, e.g. `m_member(ptr->foo)`, is a
lambda return statement, and it puts spaces around the `->`.
This removes the allocate_tls syscall and adds an archctl option to set
the fs_base for the current thread on x86-64, since you can't set that
register from userspace. enter_thread_context loads the fs_base for the
next thread on each context switch.
This also moves tpidr_el0 (the thread pointer register on AArch64) to
the register state, so it gets properly saved/restored on context
switches.
The userspace TLS allocation code is kept pretty similar to the original
kernel TLS code, aside from a couple of style changes.
We also have to add a new argument "tls_pointer" to
SC_create_thread_params, as we otherwise can't prevent race conditions
between setting the thread pointer register and signal handling code
that might be triggered before the thread pointer was set, which could
use TLS.
These changes are compatible with clang-format 16 and will be mandatory
when we eventually bump clang-format version. So, since there are no
real downsides, let's commit them now.
Either we mount from a loop device or other source, the user might want
to obfuscate the given source for security reasons, so this option will
ensure this will happen.
If passed during a mount, the source will be hidden when reading from
the /sys/kernel/df node.
This device is a block device that allows a user to effectively treat an
Inode as a block device.
The static construction method is given an OpenFileDescription reference
but validates that:
- The description has a valid custody (so it's not some arbitrary file).
Failing this requirement will yield EINVAL.
- The description custody points to an Inode which is a regular file, as
we only support (seekable) regular files. Failing this requirement
will yield ENOTSUP.
LoopDevice can be used to mount a regular file on the filesystem like
other supported types of (physical) block devices.
This makes it possible to use MakeIndexSequqnce in functions like:
template<typename T, size_t N>
constexpr auto foo(T (&a)[N])
This means AK/StdLibExtraDetails.h must now include AK/Types.h
for size_t, which means AK/Types.h can no longer include
AK/StdLibExtras.h (which arguably it shouldn't do anyways),
which requires rejiggering some things.
(IMHO Types.h shouldn't use AK::Details metaprogramming at all.
FlatPtr doesn't necessarily have to use Conditional<> and ssize_t could
maybe be in its own header or something. But since it's tangential to
this PR, going with the tried and true "lift things that cause the
cycle up to the top" approach.)
This scan code set is more advanced than the basic scan code set 1, and
is required to be supported for some bare metal hardware that might not
properly enable the PS2 first port translation in the i8042 controller.
LibWeb can now also generate bindings for keyboard events like the Pause
key, as well as other function keys (such as Right Alt, etc).
The logic for handling scan code sets is implemented by the PS2 keyboard
driver and is abstracted from the main HID KeyboardDevice code which
only handles "standard" KeyEvent(s).
This scan code set is more advanced than the basic scan code set 1, and
is required to be supported for some bare metal hardware that might not
properly enable the PS2 first port translation in the i8042 controller.
LibWeb can now also generate bindings for keyboard events like the Pause
key, as well as other function keys (such as Right Alt, etc).
The logic for handling scan code sets is implemented by the PS2 keyboard
driver and is abstracted from the main HID KeyboardDevice code which
only handles "standard" KeyEvent(s).
This will be used later on by WindowServer so it will not use the
scancode, which will represent the actual character index in the
keyboard mapping when using scan code set 2.
There's no need to have separate syscall for this kind of functionality,
as we can just have a device node in /dev, called "beep", that allows
writing tone generation packets to emulate the same behavior.
In addition to that, we remove LibC sysbeep function, as this function
was never being used by any C program nor it was standardized in any
way.
Instead, we move the userspace implementation to LibCore.
The Kernel/API directory in general shouldn't include userspace code,
but structure definitions that both are shared between the Kernel and
userspace.
All users of the ioctl API obviously use LibC so LibC is the most common
and shared library for the affected programs.
The Kernel/API directory in general shouldn't include userspace code,
but structure definitions that both are shared between the Kernel and
userspace.
LibC is the most appropriate place for these methods as they're already
included in the sys/sysmacros.h file to create a set of convenient
macros for these methods.
These syscalls are not necessary on their own, and they give the false
impression that a caller could set or get the thread name of any process
in the system, which is not true.
Therefore, move the functionality of these syscalls to be options in the
prctl syscall, which makes it abundantly clear that these operations
could only occur from a running thread in a process that sees other
threads in that process only.
This is a preparation before we can create a usable mechanism to use
filesystem-specific mount flags.
To keep some compatibility with userland code, LibC and LibCore mount
functions are kept being usable, but now instead of doing an "atomic"
syscall, they do multiple syscalls to perform the complete procedure of
mounting a filesystem.
The FileBackedFileSystem IntrusiveList in the VFS code is now changed to
be protected by a Mutex, because when we mount a new filesystem, we need
to check if a filesystem is already created for a given source_fd so we
do a scan for that OpenFileDescription in that list. If we fail to find
an already-created filesystem we create a new one and register it in the
list if we successfully mounted it. We use a Mutex because we might need
to initiate disk access during the filesystem creation, which will take
other mutexes in other parts of the kernel, therefore making it not
possible to take a spinlock while doing this.
After examination of all overriden Inode::traverse_as_directory methods
it seems like proper locking is already existing everywhere, so there's
no need to take the big process lock anymore, as there's no access to
shared process structures anyway.
These 2 are an actual separate types of syscalls, so let's stop using
special flags for bind mounting or re-mounting and instead let userspace
calling directly for this kind of actions.
This is quite useful for userspace applications that can't cope with the
restriction, but it's still useful to impose other non-configurable
restrictions by using jails.
Instead of storing x86_64 register names in `SC_create_thread_params`,
let the Kernel figure out how to pass the parameters to
`pthread_create_helper`.
We have a problem with the original utimensat syscall because when we
do call LibC futimens function, internally we provide an empty path,
and the Kernel get_syscall_path_argument method will detect this as an
invalid path.
This happens to spit an error for example in the touch utility, so if a
user is running "touch non_existing_file", it will create that file, but
the user will still see an error coming from LibC futimens function.
This new syscall gets an open file description and it provides the same
functionality as utimensat, on the specified open file description.
The new syscall will be used later by LibC to properly implement LibC
futimens function so the situation described with relation to the
"touch" utility could be fixed.
For a very long time, the kernel had only support for basic PS/2 devices
such as the PS2 AT keyboard and regular PS2 mouse (with a scroll wheel).
To adapt to this, we had very simple abstractions in place, essentially,
the PS2 devices were registered as IRQ handlers (IRQ 1 and 12), and when
an interrupt was triggered, we simply had to tell the I8042Controller to
fetch a byte for us, then send it back to the appropriate device for
further processing and queueing of either a key event, or a mouse packet
so userspace can do something meaningful about it.
When we added the VMWare mouse integration feature it was easily adapted
to this paradigm, requiring small changes across the handling code for
these devices.
This patch is a major cleanup for any future advancements in the HID
subsystem.
It ensures we do things in a much more sane manner:
- We stop using LockRefPtrs. Currently, after the initialization of the
i8042 controller, we never have to change RefPtrs in that class, as we
simply don't support PS2 hotplugging currently.
Also, we remove the unnecessary getters for keyboard and mouse devices
which also returned a LockRefPtr.
- There's a clear separation between PS2 devices and the actual device
nodes that normally exist in /dev. PS2 devices are not polled, because
when the user uses these devices, they will trigger an IRQ which when
is handled, could produce either a MousePacket or KeyEvent, depending
on the device state.
The separation is crucial for buses that are polled, for example - USB
is a polled bus and will not generate an IRQ for HID devices.
- There's a clear separation in roles of each structure. The PS2 devices
which are attached to a I8042Controller object are managing the device
state, while the generic MouseDevice and KeyboardDevice manage all
related tasks of a CharacterDevice, as well as interpreting scan code
events and mouse relative/absolute coordinates.
