Clang requires that attributes declared using the bracketed
`[[attr_name]]` syntax come before those with
`__attribute__((attr-name))`.
This fixes a Clang build error.
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)`.
In standard C++, operators `new` and `new[]` are guaranteed to return a
valid (non-null) pointer and throw an exception if the allocation
couldn't be performed. Based on this, compilers did not check the
returned pointer before attempting to use them for object construction.
To avoid this, the allocator operators were changed to be `noexcept` in
PR #7026, which made GCC emit the desired null checks. Unfortunately,
this is a non-standard feature which meant that Clang would not accept
these function definitions, as it did not match its expected
declaration.
To make compiling using Clang possible, the special "nothrow" versions
of `new` are implemented in this commit. These take a tag type of
`std::nothrow_t` (used for disambiguating from placement new/etc.), and
are allowed by the standard to return null. There is a global variable,
`std::nothrow`, declared with this type, which is also exported into the
global namespace.
To perform fallible allocations, the following syntax should be used:
```cpp
auto ptr = new (nothrow) T;
```
As we don't support exceptions in the kernel, the only way of uphold the
"throwing" new's guarantee is to abort if the allocation couldn't be
performed. Once we have proper OOM handling in the kernel, this should
only be used for critical allocations, where we wouldn't be able to
recover from allocation failures anyway.
This rewrites the dbgputch and dbgputstr system calls as wrappers of
kstdio.h.
This fixes a bug where only the Kernel's debug output was also sent to
a serial debugger, while the userspace's debug output was only sent to
the Bochs debugger.
This also fixes a bug where debug output from one process would
sometimes "interrupt" the debug output from another process in the
middle of a line.
This adds a dbgputch() alongside dbgputstr() in kstdio.h. The function
already existed as the static function debugger_out(). It has now been
exposed to users of kstdio.h.
This adds just enough stubs to make the kernel compile on x86_64. Obviously
it won't do anything useful - in fact it won't even attempt to boot because
Multiboot doesn't support ELF64 binaries - but it gets those compiler errors
out of the way so more progress can be made getting all the missing
functionality in place.
When building the kernel for x86_64 the compiler injects calls to
__cxa_guard_acquire which depends on a bunch of pthread functions
we don't have in the kernel.
This fixes#8133.
Ext2FSInode::remove_child() searches the lookup cache, so if it's not
initialized, removing the child fails. If the child was a directory,
this led to it being corrupted and having 0 children.
I also added populate_lookup_cache to add_child. I hadn't seen any
bugs there, but if the cache wasn't populated before, adding that
one entry would make it think it was populated, so that would cause
bugs later.
The `File::can_write` mechanism lets us check that writes won't block,
meaning some bytes can be immediately written to the underlying device.
This means calling `File::write` in a situation where no data could be
written is a logic error, which we `VERIFY()` in `Process::do_write()`.
TTY, in particular, processes the write in 256-byte buffered chunks.
Previously, we would assert that none of these sub-writes returned zero.
This was a logic error, as this rejected some successful writes. For
example, if there was exactly enough free space in `SlavePty`'s internal
buffer for the previous sub-write to complete fully. This made it
impossible to perform writes larger than `SlavePty`'s internal buffer.
Note that it's not an issue if `on_tty_write` returns zero, as partial
writes are handled correctly by the `buffer.read_buffered` helper. We
won't spin in a loop trying to write to a full buffer.
Fixes#8090
If we have a VGA-capable graphics adapter that we support, we should
prefer it over any legacy VGA because we wouldn't use it in legacy VGA
mode in this case.
This solves the problem where we would only use the legacy VGA card
when both a legacy VGA card as well as a VGA-mode capable adapter is
present.
Steps to reproduce:
$ cat loop.c
int main() { for (;;); }
$ gcc -o loop loop.c
$ ./loop
Terminating this process wasn't previously possible because we only
checked whether the thread should be terminated on syscall exit.
This doesn't really matter in terms of writability for the kernel text
because we set up proper page mappings anyway which prohibit writing
to the text segment. However, this makes the profiler happy which
previously died when validating the kernel's ELF program headers.
Instead, try to create the device objects in separate static methods,
and if we fail for some odd reason to allocate memory for such devices,
just panic with that reason.
We now store the device descriptor obtained from the device
during enumeration in the device's object in memory instead
of exposing all of the different members contained within it.
inode identifiers in ProcFS are encoded in a way that the parent ID is
shifted 12 bits to the left and the PID is shifted by 16 bits. This
means that the rightmost 12 bits are reserved for the file type or the
fd.
Since the to_fd and to_proc_file_type decoders only decoded the
rightmost 8 bits, decoded values would wrap around beyond values of 255,
resulting in a different value compared to what was originally encoded.
If FXSR is not present, fall back to fnsave and frstor instructions.
These instructions aren't available on the canonical i686 CPU which is
the Pentium Pro processor.
This ensures that pages returned by
MM.allocate_supervisor_physical_page() have a physical address that
is in the bottom 16MB and can thus be used by the SB16 driver for DMA.
Fixes#8092.
If we are in a shared interrupt handler, the called handlers might
indicate it was not their interrupt, so we should not increment the
call counter of these handlers.
Previously the VirtualConsole::on_tty_write() method would return an
incorrect value when an error had occurred. This prompted me to
update the TTY subsystem to use KResultOr<size_t> everywhere.
Note that there are a few minor differences between the InlineLinekdList
and IntrusiveList API, so this isn't just a pure data structure change.
- first()/last() instead of head()/tail()
- There is no need for a for_each(..) implementation, as it already
exposes the ability to do range based for loops.
This has a quirk with the AMD Hudson-2 SATA controller. [1022:7801]
Having this flag set makes the controller become stuck in a busy loop.
I decided to remove the flag instead of making it a quirk as it still
works with Qemu, VirtualBox, VMware Player and the Intel Wildcat
Point-LP SATA Controller [8086:9c83] without it, thus making it simpler
to just remove it.
Partial fix for #7738 (as it still does not work in IDE mode)
Previously, when e.g. the `SIGABRT` signal was sent to a process,
`Thread::dispatch_signal()` would invoke
`Process::terminate_due_to_signal()` which would then `::die()`. The
result `DispatchSignalResult::Terminate` is then returned to
`Thread::check_dispatch_pending_signal()` which proceeds to invoke
`Process::die()` a second time.
Change the behavior of `::check_dispatch_pending_signal()` to no longer
call `Process::die()` if it receives `::Terminate` as a signal handling
result, since that indicates that the process was already terminated.
This fixes#7289.
When you invoke a binary with a shebang line, the `execve` syscall
makes sure to pass along command line arguments to the shebang
interpreter including the path to the binary to execute.
This does not work well when the binary lives in $PATH. For example,
given this script living in `/usr/local/bin/my-script`:
#!/bin/my-interpreter
echo "well hello friends"
When executing it as `my-script` from outside `/usr/local/bin/`, it is
executed as `/bin/my-interpreter my-script`. To make sure that the
interpreter can find the binary to execute, we need to replace the
first argument with an absolute path to the binary, so that the
resulting command is:
/bin/my-interpreter /usr/local/bin/my-script
