This commit converts naked `new`s to `AK::try_make` and `AK::try_create`
wherever possible. If the called constructor is private, this can not be
done, so we instead now use the standard-defined and compiler-agnostic
`new (nothrow)`.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
Switch to using type-safe bitwise operators for the BlockFlags class,
this cleans up a lot of boilerplate casts which are necessary when the
enum is declared as `enum class`.
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
For some reason we were keeping the bits 04777 in file modes. That
doesn't seem right and I can't think of a reason why the set-uid bit
should be allowed to slip through.
..and allow implicit creation of KResult and KResultOr from ErrnoCode.
This means that kernel functions that return those types can finally
do "return EINVAL;" and it will just work.
There's a handful of functions that still deal with signed integers
that should be converted to return KResults.
Problem:
- Many constructors are defined as `{}` rather than using the ` =
default` compiler-provided constructor.
- Some types provide an implicit conversion operator from `nullptr_t`
instead of requiring the caller to default construct. This violates
the C++ Core Guidelines suggestion to declare single-argument
constructors explicit
(https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c46-by-default-declare-single-argument-constructors-explicit).
Solution:
- Change default constructors to use the compiler-provided default
constructor.
- Remove implicit conversion operators from `nullptr_t` and change
usage to enforce type consistency without conversion.
When ProcFS could no longer allocate KBuffer objects to serve calls to
read, it would just return 0, indicating EOF. This then triggered
parsing errors because code assumed it read the file.
Because read isn't supposed to return ENOMEM, change ProcFS to populate
the file data upon file open or seek to the beginning. This also means
that calls to open can now return ENOMEM if needed. This allows the
caller to either be able to successfully open the file and read it, or
fail to open it in the first place.
This makes the Scheduler a lot leaner by not having to evaluate
block conditions every time it is invoked. Instead evaluate them as
the states change, and unblock threads at that point.
This also implements some more waitid/waitpid/wait features and
behavior. For example, WUNTRACED and WNOWAIT are now supported. And
wait will now not return EINTR when SIGCHLD is delivered at the
same time.
Since the receiving socket isn't yet known at packet receive time,
keep timestamps for all packets.
This is useful for keeping statistics about in-kernel queue latencies
in the future, and it can be used to implement SO_TIMESTAMP.
Since the CPU already does almost all necessary validation steps
for us, we don't really need to attempt to do this. Doing it
ourselves doesn't really work very reliably, because we'd have to
account for other processors modifying virtual memory, and we'd
have to account for e.g. pages not being able to be allocated
due to insufficient resources.
So change the copy_to/from_user (and associated helper functions)
to use the new safe_memcpy, which will return whether it succeeded
or not. The only manual validation step needed (which the CPU
can't perform for us) is making sure the pointers provided by user
mode aren't pointing to kernel mappings.
To make it easier to read/write from/to either kernel or user mode
data add the UserOrKernelBuffer helper class, which will internally
either use copy_from/to_user or directly memcpy, or pass the data
through directly using a temporary buffer on the stack.
Last but not least we need to keep syscall params trivial as we
need to copy them from/to user mode using copy_from/to_user.
MemoryManager cannot use the Singleton class because
MemoryManager::initialize is called before the global constructors
are run. That caused the Singleton to be re-initialized, causing
it to create another MemoryManager instance.
Fixes#3226
This fixes a bunch of unchecked kernel reads and writes, seems like they
would might exploitable :). Write of sockaddr_in size to any address you
please...
Note that the data member is of type ImmutableBufferArgument, which has
no Userspace<T> usage. I left it alone for now, to be fixed in a future
change holistically for all usages.
The way getsockopt is implemented for socket types requires us to push
down Userspace<T> using into those interfaces. This change does so, and
utilizes proper copy implementations instead of the kind of haphazard
pointer dereferencing that was occurring there before.
Allow passing in an optional timeout to Thread::block and move
the timeout check out of Thread::Blocker. This way all Blockers
implicitly support timeouts and don't need to implement it
themselves. Do however allow them to override timeouts (e.g.
for sockets).
We now have BlockResult::WokeNormally and BlockResult::NotBlocked,
both of which indicate no error. We can no longer just check for
BlockResult::WokeNormally and assume anything else must be an
interruption.
These new syscalls allow you to send and receive file descriptors over
a local domain socket. This will enable various privilege separation
techniques and other good stuff. :^)
We're going to make use of it in the next commit. But the idea is we want to
know how this File (more specifically, InodeFile) was opened in order to decide
how chown()/chmod() should behave, in particular whether it should be allowed or
not. Note that many other File operations, such as read(), write(), and ioctl(),
already require the caller to pass a FileDescription.
