The OpenFileDescription class already offers the necessary functionlity,
so implementing this was only a matter of following the structure for
`read` while handling the additional `offset` argument.
Having these bits of code factored out not only prevents duplication
now, but will also allow us to implement pread without repeating
ourselves (too much).
Values in `ioctl` are given through a pointer, but ioctl's FIONBIO
implementation was interpreting this pointer as an integer directly.
This meant that programs using `ioctl` to set a file descriptor in
blocking mode met with incorrect behavior: they passed a non-null
pointer pointing to a value of 0, but the kernel interpreted the pointer
as a non-zero integer, thus making the file non-blocking.
This commit fixes this behavior by reading the value from the userspace
pointer and using that to set the non-blocking flag on the file
descriptor.
This bug was found while trying to run the openssl tool on serenity,
which used `ioctl` to ensure newly-created sockets are in blocking mode.
Normally, trying to truncate a SysFSInode should result in EPERM error.
However, as suggested by Ali (@alimpfard), we can allow the PowerState
node to be "truncated" so one can open that file with O_TRUNC option.
Likewise, we also need to provide a way to set modified time on SysFS
inodes. For most inodes, we should return ENOTIMPL error, but for the
power state switch, we ignore the modified time setting and just return
KSuccess.
These fixes allow to do "echo -n 1 > /sys/firmware/power_state" in Shell
after gaining root permissions, to switch the power state.
There's basically no real difference in software between a SATA harddisk
and IDE harddisk. The difference in the implementation is for the host
bus adapter protocol and registers layout.
Therefore, there's no point in putting a distinction in software to
these devices.
This change also greatly simplifies and removes stale APIs and removes
unnecessary parameters in constructor calls, which tighten things
further everywhere.
While I was working on LibWeb, I got a page fault at 0xe0e0e0e4.
This indicates a destroyed RefPtr if compiled with SANITIZE_PTRS
defined. However, the page fault handler didn't print out this
indication.
This makes the page fault handler print out a note if the faulting
address looks like a recently destroyed RefPtr, OwnPtr, NonnullRefPtr,
NonnullOwnPtr, ThreadSafeRefPtr or ThreadSafeNonnullRefPtr. It will
only do this if SANITIZE_PTRS is defined, as smart pointers don't get
scrubbed without it being defined.
This exposes a small subset of the information exposed by the Linux
equivalent, and will be used to optimize applications that would like
to know the current CPU usage statistics, but don't want to read all of
the unrelated information in /proc/all
Some time ago, automatic locking was added to the AK smart pointers to
paper over various race conditions in the kernel. Until we've actually
solved the issues in the kernel, we're stuck with the locking.
However, we don't need to punish single-threaded userspace programs with
the high cost of locking. This patch moves the thread-safe variants of
RefPtr, NonnullRefPtr, WeakPtr and RefCounted into Kernel/Library/.
This change is another minor step towards removing `AK::String` from
the Kernel. Instead of dynamically allocating the storage_name we can
instead allocate it via a KString in the factory for each device, and
then push the device name down into the StorageDevice base class.
We don't have a way of doing `AK::String::formatted(..)` with a KString
at the moment, so cleaning that up will be left for a later day.
Previously there was a mix of returning plain strings and returning
explicit string views using `operator ""sv`. This change switches them
all to standardized on `operator ""sv` as it avoids a call to strlen.
Previously there was a mix of returning plain strings and returning
explicit string views using `operator ""sv`. This change switches them
all to standardized on `operator ""sv` as it avoids a call to strlen.
For now, this can only query microseconds since boot.
Use this to print a timestamp every second. This busy-loops
until a second has passed. This might be a good first use of
interrupts soon.
qemu used to not implement this timer at some point, but
it seems to work fine even in qemu now (qemu v 5.2.0).
SonarCloud flagged this "Code Smell", where we are accessing these
static methods as if they are instance methods. While it is technically
possible, it is very confusing to read when you realize they are static
functions.
SonarCloud flagged this "Code Smell", where we are accessing these
static methods as if they are instance methods. While it is technically
possible, it is very confusing to read when you realize they are static
functions.
When a process with a large heap crashes (e.g WebContent), it gets very
cumbersome to dump out a huge amount of memory.
In the vast majority of cases, we're only interested in generating a
nice backtrace from the coredump, so let's have the kernel skip over
userspace heap regions when dumping memory for now.
This is not ideal, and almost a little bit ugly, but it does make
investigating 500 MiB WebContent crashes significantly easier for now.
After building and running
objcopy -O binary Build/aarch64/Kernel/Prekernel/Prekernel \
/media/sdcard/kernel8.img
things start booting on an actual RPi4 :^)
(Assuming the sdcard contains RPi firmware, an empty config.txt,
and no other kernel*.img files).
