This ensures that both mutable and immutable access to the protected
data of a process is serialized.
Note that there may still be multiple TOCTOU issues around this, as we
have a bunch of convenience accessors that make it easy to introduce
them. We'll need to audit those as well.
By protecting all the RefPtr<Custody> objects that may be accessed from
multiple threads at the same time (with spinlocks), we remove the need
for using LockRefPtr<Custody> (which is basically a RefPtr with a
built-in spinlock.)
Instead, allocate when acquiring the lock on m_fds struct, which is
safer to do in terms of safely mutating the m_fds struct, because we
don't use the big process lock in this syscall.
Required by Discord, which polyfills it by taking the existing native
object, polyfilling missing functions and setting window.performance to
it.
This is a hard requirement as this is done in strict mode with no
try/catch and thus causes their JavaScript to stop progressing.
We already did this but it called the @@iterator method of
%Array.prototype% visible to the user for example by overriding that
method. This should not be visible so we use a special version of
SuperCall now.
Although this already works in most cases in non-kvm serenity cases the
cosh and other math function tend to return incorrect values for
Infinity. This makes sure that whatever the underlying cosh function
returns Math.cosh conforms to the spec.
This allows us to treat unqualified, minimally-qualified, and
fully-qualified emojis the same as long as emoji filenames are in their
least qualified form (with respect to emoji presentation).
For example, the transgender flag emoji has 4 possible forms:
1F3F3 FE0F 200D 26A7 FE0F ; fully-qualified # 🏳️⚧️
1F3F3 200D 26A7 FE0F ; unqualified # 🏳⚧️
1F3F3 FE0F 200D 26A7 ; unqualified # 🏳️⚧
1F3F3 200D 26A7 ; unqualified # 🏳⚧
In order to treat them all as the same, we now drop all forms down
to 1F3F3 200D 26A7 (skipping any FE0F codepoints) and then do the
lookup for that form.
Verifies that emoji filenames:
- Contain only uppercase letters, numbers, +, and _
- Use _ and a separator between codepoints, not +
- Do not include the U+FE0F emoji presentation specifier
This patch adds the NGROUPS_MAX constant and enforces it in
sys$setgroups() to ensure that no process has more than 32 supplementary
group IDs.
The number doesn't mean anything in particular, just had to pick a
number. Perhaps one day we'll have a reason to change it.
Now that these operate on the neatly atomic and immutable Credentials
object, they should no longer require the process big lock for
synchronization. :^)
This patch adds a new object to hold a Process's user credentials:
- UID, EUID, SUID
- GID, EGID, SGID, extra GIDs
Credentials are immutable and child processes initially inherit the
Credentials object from their parent.
Whenever a process changes one or more of its user/group IDs, a new
Credentials object is constructed.
Any code that wants to inspect and act on a set of credentials can now
do so without worrying about data races.
Until now, our kernel has reimplemented a number of AK classes to
provide automatic internal locking:
- RefPtr
- NonnullRefPtr
- WeakPtr
- Weakable
This patch renames the Kernel classes so that they can coexist with
the original AK classes:
- RefPtr => LockRefPtr
- NonnullRefPtr => NonnullLockRefPtr
- WeakPtr => LockWeakPtr
- Weakable => LockWeakable
The goal here is to eventually get rid of the Lock* classes in favor of
using external locking.
Instead of having two separate implementations of AK::RefCounted, one
for userspace and one for kernelspace, there is now RefCounted and
AtomicRefCounted.
After commit 91a03bc6ae we no longer try
to discover files for exec-ing by simply trying to exec on them, but we
check for the files existence by using `Core::file::exists()` first.
Contrary to the old solution, this now requires the `rpath` pledge, so
pledge it to keep `strace` from crashing when using non-absolute paths.
All users which relied on the default constructor use a None lock rank
for now. This will make it easier to in the future remove LockRank and
actually annotate the ranks by searching for None.
Unlike Clang, GCC does not support 8-byte atomics on i686 with the
-mno-80387 flag set, so until that is fixed, implement a minimal set of
atomics that are currently required.
Signal dispatch is already protected by the global scheduler lock, but
in some cases we also took Thread::m_lock for some reason. This led to
a number of different deadlocks that started showing up with 4+ CPU's
attached to the system.
As a first step towards solving this, simply don't take the thread lock
and let the scheduler lock cover it.
Eventually, we should work in the other direction and break the
scheduler lock into much finer-grained locks, but let's get out of the
deadlock swamp first.
This is not necessary, and is a leftover from before Thread started
using the ListedRefCounted pattern to be safely removed from lists on
the last call to unref().
As soon as we've saved CR2 (the faulting address), we can re-enable
interrupt processing. This should make the kernel more responsive under
heavy fault loads.
This fixes an issue where a sharing process would map the "lazy
committed page" early and then get stuck with that page even after
it had been replaced in the VMObject by a page fault.
Regressed in 27c1135d30, which made it
happen every time with the backing bitmaps used for WebContent.
This mirrors the "open parent directory" action, but traverses the
breadcrumbbar segments from left-to-right instead. The name is a little
bit strange, and maybe we can come up with something better.
It does feel pretty nice to use though. :^)
Region::physical_page() now takes the VMObject lock while accessing the
physical pages array, and returns a RefPtr<PhysicalPage>. This ensures
that the array access is safe.
Region::physical_page_slot() now VERIFY()'s that the VMObject lock is
held by the caller. Since we're returning a reference to the physical
page slot in the VMObject's physical page array, this is the best we
can do here.
Note that SMP is still off by default, but this basically removes the
weird "SMP on but threads don't get scheduled" behavior we had by
default. If you pass "smp=on" to the kernel, you now get SMP. :^)
We really only need the VMObject lock when accessing the physical pages
array, so once we have a strong pointer to the physical page we want to
remap, we can give up the VMObject lock.
This fixes a deadlock I encountered while building DOOM on SMP.
When handling a page fault, we only need to remap the faulting region in
the current process. There's no need to traverse *all* regions that map
the same VMObject and remap them cross-process as well.
Those other regions will get remapped lazily by their own page fault
handlers eventually. Or maybe they won't and we avoided some work. :^)
- Instead of holding the VMObject lock across physical page allocation
and quick-map + copy, we now only hold it when updating the VMObject's
physical page slot.
Noticed that mouse-overing the ruler area in the TextEditor
does not change the cursor to the default cursor, instead, the
beam cursor is used, which does not look nice.
This PR extends the mousemove event and introduces a new
set_editing_cursor() function that takes care of setting the
cursor for the editor area.
