Since "rings" typically refer to code execution and user processes
can also execute in ring 0, rename these functions to more accurately
describe what they mean: kernel processes and user processes.
The ring is determined based on the CS register. This fixes crashes
being handled as ring 3 crashes even though EIP/CS clearly showed
that the crash happened in the kernel.
In addition to being the proper POSIX etiquette, it seems like a bad idea
for issues like the one seen in #3428 to result in a kernel crash. This patch
replaces the current behavior of failing on insufficient buffer size to truncating
SOCK_RAW messages to the buffer size. This will have to change if/when MSG_PEEK
is implemented, but for now this behavior is more compliant and logical than
just bailing.
By being a bit too greedy and only allocating how much we need for
the failing allocation, we can end up in an infinite loop trying
to expand the heap further. That's because there are other allocations
(e.g. logging, vmobjects, regions, ...) that happen before we finally
retry the failed allocation request.
Also fix allocating in page size increments, which lead to an assertion
when the heap had to grow more than the 1 MiB backup.
Rather than trying to find a contiguous set of bits of size 1, just
find one single available bit using a hint.
Also, try to randomize returned physical pages a bit by placing them
into a 256 entry queue rather than making them available immediately.
Then, once the queue is filled, pick a random one, make it available
again and use that slot for the latest page to be returned.
In c3d231616c we added the atomic variable
m_have_any_unmasked_pending_signals tracking the state of pending signals.
Add helper functions that automatically update this variable as needed.
We need to wait until a thread is fully set up and ready for running
before attempting to deliver a signal. Otherwise we may not have a
user stack yet.
Also, remove the Skip0SchedulerPasses and Skip1SchedulerPass thread
states that we don't really need anymore with software context switching.
Fixes the kernel crash reported in #3419
Previously, it was kept as just a time_t and the sub-second
offset was inferred from the monotonic clock. This means that
sub-second time adjustments were ignored.
Now that `ntpquery -s` can pass in a time with sub-second
precision, it makes sense to keep time at that granularity
in the kernel.
After this, `ntpquery -s` immediately followed by `ntpquery` shows
an offset of 0.02s (that is, on the order of network roundtrip time)
instead of up to 0.75s previously.
Instead of FileDescriptor branching on the type of File it's wrapping,
add a File::stat() function that can be overridden to provide custom
behavior for the stat syscalls.
Sometimes a physical underlying page may be there, but we may be
unable to allocate a page table that may be needed to map it. Bubble
up such mapping errors so that they can be handled more appropriately.
It may be impossible to allocate more backup memory after expanding
the heap if memory is running low. In that case we wouldn't allocate
backup memory until trying to expand the heap again. But we also
wouldn't take advantage of using removed memory as backup, which means
that no backup memory would be available when the heap needs to grow
again, causing subsequent expansion to fail because there is no
backup memory.
The process of expanding memory requires allocations and deallocations
on the heap itself. So, while we're trying to expand the heap, don't
remove memory just because we might briefly not need it. Also prevent
recursive expansion attempts.
If allocating a page table triggers purging memory, we need to call
quickmap_pd again to make sure the underlying physical page is
remapped to the correct one. This is needed because purging itself
may trigger calls to ensure_pte as well.
Fixes#3370
When cloning a purgeable memory region (which happens on fork),
we need to preserve the "was purged" and "volatile" state of the
original region, or they will always appear as non-volatile and
unpurged regions in the child process.
Fixes#3374.
The exit condition for the loop was sizeof(m_features) * 8,
which was 32. Presumably this was supposed to mean 32 bits, but it
actually made it stop as soon as it reached the 6th bit.
Also add detection for more SIMD CPU features.
Add an ExpandableHeap and switch kmalloc to use it, which allows
for the kmalloc heap to grow as needed.
In order to make heap expansion to work, we keep around a 1 MiB backup
memory region, because creating a region would require space in the
same heap. This means, the heap will grow as soon as the reported
utilization is less than 1 MiB. It will also return memory if an entire
subheap is no longer needed, although that is rarely possible.
A change introduced in 5e01234 made it the resposibility of each
filesystem to have the file types returned from
'traverse_as_directory' match up with the DT_* types.
However, this caused corruption of the Ext2FS file format because
the Ext2FS uses 'traverse_as_directory' internally when manipulating
the file system. The result was a mixture between EXT2_FT_* and DT_*
file types in the internal Ext2FS structures.
Starting with this commit, the conversion from internal filesystem file
types to the user facing DT_* types happens at a later stage,
in the 'FileDescription::get_dir_entries' function which is directly
used by sys$get_dir_entries.
This fixes an issue we had in the git port where git would not
recognize untracked files (for example in 'git status').
When git used readdir, the 'd_type' field in the dirent struct contained
bad values (Specifically, it contained the values defiend in
Kernel/FileSystem/ext2_fs.h instead of the ones in LibC/dirent.h).
After this fix, we can create a new git repository with 'git init', and
then stage and commit files as usual.
An IRQ handler should always be ready to respond to any IRQ.
We must remember that hardware can generate IRQs without any interaction
from our code at all. Ignoring IRQs in such cases is obviously not the
right thing to do.
The JS tests pointed out that the implementation in DateTime
had an off-by-one in the month when doing the leap year check,
so this change fixes that bug.
