`-Wnull-dereference` has found a lot of "possible null dereferences" in userland.
However, in the kernel, no warnings occurred. To keep it that way,
preemptivly add the flag here and remove it once it is enabled system
wide.
This flag makes the compiler check statically for a null deref. It does
not take into account any human-imposed invariants and as such, may need a
`VERIFY(ptr);`, `if(ptr)`, or `if(!ptr)` before using a pointer.
However, as long as a pointer is not reassigned,
the verify will be valid, meaning that adding `VERIFY` can be done sparingly.
This should allow creating intrusive lists that have smart pointers,
while remaining free (compared to the impl before this commit) when
holding raw pointers :^)
As a sidenote, this also adds a `RawPtr<T>` type, which is just
equivalent to `T*`.
Note that this does not actually use such functionality, but is only
expected to pave the way for #6369, to replace NonnullRefPtrVector<T>
with intrusive lists.
As it is with zero-cost things, this makes the interface a bit less nice
by requiring the type name of what an `IntrusiveListNode` holds (and
optionally its container, if not RawPtr), and also requiring the type of
the container (normally `RawPtr`) on the `IntrusiveList` instance.
This patch adds a few missing ioctls which were required by Wine.
SIOCGIFNETMASK, SIOCGIFBRDADDR and SIOCGIFMTU are fully implemented,
while SIOCGIFFLAGS and SIOCGIFCONF are stubs.
This flag warns on classes which have `virtual` functions but do not
have a `virtual` destructor.
This patch adds both the flag and missing destructors. The access level
of the destructors was determined by a two rules of thumb:
1. A destructor should have a similar or lower access level to that of a
constructor.
2. Having a `private` destructor implicitly deletes the default
constructor, which is probably undesirable for "interface" types
(classes with only virtual functions and no data).
In short, most of the added destructors are `protected`, unless the
compiler complained about access.
Reading from the mapping doesn't work when the text segment has a non-zero
offset because in that case the first mapped page doesn't contain the ELF
header.
This should provide some speed up, as currently searches for regions
containing a given address were performed in O(n) complexity, while
this container allows us to do those in O(logn).
This does not affect functionality right now, but it means that the
regions vector will now never have any overlapping regions, which will
allow the use of balance binary search trees instead of a vector in the
future. (since they require keys to be exclusive)
This pattern felt really cluttery:
auto result = something();
if (result.is_error())
return result;
Since it leaves "result" lying around in the no-error case.
Let's use some C++17 if initializer expressions to improve this:
if (auto result = something(); result.is_error())
return result;
Now the "result" goes out of scope if we don't need it anymore.
This is doubly nice since we're also free to reuse the "result"
name later in the same function.
This commit makes the user-facing StdLibExtras templates and utilities
arguably more nice-looking by removing the need to reach into the
wrapper structs generated by them to get the value/type needed.
The C++ standard library had to invent `_v` and `_t` variants (likely
because of backwards compat), but we don't need to cater to any codebase
except our own, so might as well have good things for free. :^)
It's perfectly valid for ext2 inodes to have blocks with index 0.
It means that no physical block was allocated for that area of an inode
and we should treat it as if it's filled with zeroes.
Fixes#6139.
Double kfree() is exceedingly rare in our kernel since we use automatic
memory management and smart pointers for almost all code. However, it
doesn't hurt to do some basic checking that might one day catch bugs.
This patch makes us VERIFY that we don't already consider the first
chunk of a kmalloc() allocation free when kfree()'ing it.
I dont know why we do a fast path in the Kernel, but not in Userspace
Also simplified the byte explosion in memset to "explode_byte"
it even seemed so, that we missed the highest byte when memseting something
The first one is for disabling the PS2 controller, the other one is for
disabling physical storage enumeration.
We can't be sure any machine will work with our implementation,
therefore this will help us to test more machines.
We need to do it to let real hardware to put the correct voltages
on the wire.
Apparently my ICH7 machine refused to boot, and was reading lots of
garbage from an unconnected IDE channel. It was fixed after I added a
delay of 20 microseconds. It probably can be reduced, I just took a safe
value and it seems to work correctly without any problems :)
Now the kernel supports 2 ECAM access methods.
MMIOAccess was renamed to WindowedMMIOAccess and is what we had until
now - each device that is detected on boot is assigned to a
memory-mapped window, so IO operations on multiple devices can occur
simultaneously due to creating multiple virtual mappings, hence the name
is a memory-mapped window.
This commit adds a new class called MMIOAccess (not to be confused with
the old MMIOAccess class). This class creates one memory-mapped window.
On each IO operation on a configuration space of a device, it maps the
requested PCI bus region to that window. Therefore it holds a SpinLock
during the operation to ensure that no other PCI bus region was mapped
during the call.
A user can choose to either use PCI ECAM with memory-mapped window
for each device, or for an entire bus. By default, the kernel prefers to
map the entire PCI bus region.
Apparently we don't enable PCI ECAM (MMIO access to the PCI
configuration space) even if we can. This is a regression, as it was
enabled in the past and in unknown time it was regressed.
The CommandLine::is_mmio_enabled method was renamed to
CommandLine::is_pci_ecam_enabled to better represent the meaning
of this method and what it determines.
Also, an UNMAP_AFTER_INIT macro was removed from a method
in the MMIOAccess class as it halted the system when the kernel
tried to access devices after the boot process.
The end goal of this commit is to allow to boot on bare metal with no
PS/2 device connected to the system. It turned out that the original
code relied on the existence of the PS/2 keyboard, so VirtualConsole
called it even though ACPI indicated the there's no i8042 controller on
my real machine because I didn't plug any PS/2 device.
The code is much more flexible, so adding HID support for other type of
hardware (e.g. USB HID) could be much simpler.
Briefly describing the change, we have a new singleton called
HIDManagement, which is responsible to initialize the i8042 controller
if exists, and to enumerate its devices. I also abstracted a bit
things, so now every Human interface device is represented with the
HIDDevice class. Then, there are 2 types of it - the MouseDevice and
KeyboardDevice classes; both are responsible to handle the interface in
the DevFS.
PS2KeyboardDevice, PS2MouseDevice and VMWareMouseDevice classes are
responsible for handling the hardware-specific interface they are
assigned to. Therefore, they are inheriting from the IRQHandler class.
This reverts commit 36a82188a8.
This register is write-only for the firmware (BIOS), and read-only for
us so we shouldn't set the PCI IRQ line never.
The firmware figured out the IRQ routing to the PIC for us, so changing
it won't affect anything. I was mistaken when I thought that changing
the value of this register will allow us to change its interrupt line,
like when changing a PCI BAR to relocate device resources as desired
with the requirements of the OS.
Also handle native and compatibility channel modes together, so if only
one IDE channel was set to work on PCI native mode, we need to handle it
separately, so the other channel continue to operate with the legacy IO
ports and interrupt line.
This is done also by linux (signal.c:936 in v5.11) at least.
It's a pretty handy notification that allows the parent process to skip
going through a `waitpid` and guesswork to figure out the current state
of a child process.
Added a dummy TIOCSTI ioctl placeholder. This is a dangerous ioctl that
can be used to inject input into a tty. Added for compatibility. Always
fails with EIO.
Previously, Process::do_write would error if the O_APPEND flag was set
on a non-seekable file.
Other systems (such as Linux) seem to be OK with doing this, so we now
do not attempt to seek to the end the file if it's not seekable.
Most coredumps contain large amounts of consecutive null bytes and as
such are a prime candidate for compression.
This commit makes CrashDaemon compress files once the kernel finishes
emitting them, as well as adds the functionality needed in LibCoreDump
to then parse them.
This is a "quirk" I've observed on a Intel ICH7 test machine. Apparently
we need to select the device (master or slave) before starting to work
with the bus master register.
It's very possible that other machines are requiring this step to happen
before the DMA transfer can occur correctly.
Also, when reading with DMA, we should set the transfer direction before
clearing the interrupt status.
For the sake of completeness, I added a few lines in places that I
deemed it to be reasonable to clear the interrupt status there.
