Rather than make a global accessor for this sort of thing. We can make
it a part of the thread interface itself. This allows getting rid of a
hidden global accessor in the kernel code.
Makes it an instantiable class like it is in the actual kernel. This
will also allow removing reliance on global accessors in a following
change, now that we can encapsulate a reference to the system instance
in the class.
Within the kernel, shared memory and transfer memory facilities exist as
completely different kernel objects. They also have different validity
checking as well. Therefore, we shouldn't be treating the two as the
same kind of memory.
They also differ in terms of their behavioral aspect as well. Shared
memory is intended for sharing memory between processes, while transfer
memory is intended to be for transferring memory to other processes.
This breaks out the handling for transfer memory into its own class and
treats it as its own kernel object. This is also important when we
consider resource limits as well. Particularly because transfer memory
is limited by the resource limit value set for it.
While we currently don't handle resource limit testing against objects
yet (but we do allow setting them), this will make implementing that
behavior much easier in the future, as we don't need to distinguish
between shared memory and transfer memory allocations in the same place.
Now that we have the address arbiter extracted to its own class, we can
fix an innaccuracy with the kernel. Said inaccuracy being that there
isn't only one address arbiter. Each process instance contains its own
AddressArbiter instance in the actual kernel.
This fixes that and gets rid of another long-standing issue that could
arise when attempting to create more than one process.
Similar to how WaitForAddress was isolated to its own function, we can
also move the necessary conditional checking into the address arbiter
class itself, allowing us to hide the implementation details of it from
public use.
Rather than let the service call itself work out which function is the
proper one to call, we can make that a behavior of the arbiter itself,
so we don't need to directly expose those implementation details.
Places all of the functions for address arbiter operation into a class.
This will be necessary for future deglobalizing efforts related to both
the memory and system itself.
Removes a few inclusion dependencies from the headers or replaces
existing ones with ones that don't indirectly include the required
headers.
This allows removing an inclusion of core/memory.h, meaning that if the
memory header is ever changed in the future, it won't result in
rebuilding the entirety of the HLE services (as the IPC headers are used
quite ubiquitously throughout the HLE service implementations).
Gets rid of the largest set of mutable global state within the core.
This also paves a way for eliminating usages of GetInstance() on the
System class as a follow-up.
Note that no behavioral changes have been made, and this simply extracts
the functionality into a class. This also has the benefit of making
dependencies on the core timing functionality explicit within the
relevant interfaces.
Places all of the timing-related functionality under the existing Core
namespace to keep things consistent, rather than having the timing
utilities sitting in its own completely separate namespace.
Looking into the implementation of the C++ standard facilities that seem
to be within all modules, it appears that they use 7 as a break reason
to indicate an uncaught C++ exception.
This was primarily found via the third last function called within
Horizon's equivalent of libcxxabi's demangling_terminate_handler(),
which passes the value 0x80000007 to svcBreak.
This is a bounds check to ensure that the thread priority is within the
valid range of 0-64. If it exceeds 64, that doesn't necessarily mean
that an actual priority of 64 was expected (it actually means whoever
called the function screwed up their math).
Instead clarify the message to indicate the allowed range of thread
priorities.
Now that we handle the kernel capability descriptors we can correct
CreateThread to properly check against the core and priority masks
like the actual kernel does.
This makes the naming more closely match its meaning. It's just a
preferred core, not a required default core. This also makes the usages
of this term consistent across the thread and process implementations.
In all cases that these functions are needed, the VMManager can just be
retrieved and used instead of providing the same functions in Process'
interface.
This also makes it a little nicer dependency-wise, since it gets rid of
cases where the VMManager interface was being used, and then switched
over to using the interface for a Process instance. Instead, it makes
all accesses uniform and uses the VMManager instance for all necessary
tasks.
All the basic memory mapping functions did was forward to the Process'
VMManager instance anyways.
If a thread handle is passed to svcGetProcessId, the kernel attempts to
access the process ID via the thread's instance's owning process.
Technically, this function should also be handling the kernel debug
objects as well, however we currently don't handle those kernel objects
yet, so I've left a note via a comment about it to remind myself when
implementing it in the future.
In the previous change, the memory writing was moved into the service
function itself, however it still had a problem, in that the entire
MemoryInfo structure wasn't being written out, only the first 32 bytes
of it were being written out. We still need to write out the trailing
two reference count members and zero out the padding bits.
Not doing this can result in wrong behavior in userland code in the following
scenario:
MemoryInfo info; // Put on the stack, not quaranteed to be zeroed out.
svcQueryMemory(&info, ...);
if (info.device_refcount == ...) // Whoops, uninitialized read.
This can also cause the wrong thing to happen if the user code uses
std::memcmp to compare the struct, with another one (questionable, but
allowed), as the padding bits are not guaranteed to be a deterministic
value. Note that the kernel itself also fully zeroes out the structure
before writing it out including the padding bits.
Moves the memory writes directly into QueryProcessMemory instead of
letting the wrapper function do it. It would be inaccurate to allow the
handler to do it because there's cases where memory shouldn't even be
written to. For example, if the given process handle is invalid.
HOWEVER, if the memory writing is within the wrapper, then we have no
control over if these memory writes occur, meaning in an error case, 68
bytes of memory randomly get trashed with zeroes, 64 of those being
written to wherever the memory info address points to, and the remaining
4 being written wherever the page info address points to.
One solution in this case would be to just conditionally check within
the handler itself, but this is kind of smelly, given the handler
shouldn't be performing conditional behavior itself, it's a behavior of
the managed function. In other words, if you remove the handler from the
equation entirely, does the function still retain its proper behavior?
In this case, no.
Now, we don't potentially trash memory from this function if an invalid
query is performed.
Amends the MemoryState enum to use the same values like the actual
kernel does. Also provides the necessary operators to operate on them.
This will be necessary in the future for implementing
svcSetMemoryAttribute, as memory block state is checked before applying
the attribute.
The Process object kept itself alive indefinitely because its handle_table
contains a SharedMemory object which owns a reference to the same Process object,
creating a circular ownership scenario.
Break that up by storing only a non-owning pointer in the SharedMemory object.
This was only ever public so that code could check whether or not a
handle was valid or not. Instead of exposing the object directly and
allowing external code to potentially mess with the map contents, we
just provide a member function that allows checking whether or not a
handle is valid.
This makes all member variables of the VMManager class private except
for the page table.
While partially correct, this service call allows the retrieved event to
be null, as it also uses the same handle to check if it was referring to
a Process instance. The previous two changes put the necessary machinery
in place to allow for this, so we can simply call those member functions
here and be done with it.
This function simply does a handle table lookup for a writable event
instance identified by the given handle value. If a writable event
cannot be found for the given handle, then an invalid handle error is
returned. If a writable event is found, then it simply signals the
event, as one would expect.
svcCreateEvent operates by creating both a readable and writable event
and then attempts to add both to the current process' handle table.
If adding either of the events to the handle table fails, then the
relevant error from the handle table is returned.
If adding the readable event after the writable event to the table
fails, then the writable event is removed from the handle table and the
relevant error from the handle table is returned.
Note that since we do not currently test resource limits, we don't check
the resource limit table yet.
Two kernel object should absolutely never have the same handle ID type.
This can cause incorrect behavior when it comes to retrieving object
types from the handle table. In this case it allows converting a
WritableEvent into a ReadableEvent and vice-versa, which is undefined
behavior, since the object types are not the same.
This also corrects ClearEvent() to check both kernel types like the
kernel itself does.
The kernel uses the handle table of the current process to retrieve the
process that should be used to retrieve certain information. To someone
not familiar with the kernel, this might raise the question of "Ok,
sounds nice, but doesn't this make it impossible to retrieve information
about the current process?".
No, it doesn't, because HandleTable instances in the kernel have the
notion of a "pseudo-handle", where certain values allow the kernel to
lookup objects outside of a given handle table. Currently, there's only
a pseudo-handle for the current process (0xFFFF8001) and a pseudo-handle
for the current thread (0xFFFF8000), so to retrieve the current process,
one would just pass 0xFFFF8001 into svcGetInfo.
The lookup itself in the handle table would be something like:
template <typename T>
T* Lookup(Handle handle) {
if (handle == PSEUDO_HANDLE_CURRENT_PROCESS) {
return CurrentProcess();
}
if (handle == PSUEDO_HANDLE_CURRENT_THREAD) {
return CurrentThread();
}
return static_cast<T*>(&objects[handle]);
}
which, as is shown, allows accessing the current process or current
thread, even if those two objects aren't actually within the HandleTable
instance.
Our implementation of svcGetInfo was slightly incorrect in that we
weren't doing proper error checking everywhere. Instead, reorganize it
to be similar to how the kernel seems to do it.
The opposite of the getter functions, this function sets the limit value
for a particular ResourceLimit resource category, with the restriction
that the new limit value must be equal to or greater than the current
resource value. If this is violated, then ERR_INVALID_STATE is returned.
e.g.
Assume:
current[Events] = 10;
limit[Events] = 20;
a call to this service function lowering the limit value to 10 would be
fine, however, attempting to lower it to 9 in this case would cause an
invalid state error.
This kernel service function is essentially the exact same as
svcGetResourceLimitLimitValue(), with the only difference being that it
retrieves the current value for a given resource category using the
provided resource limit handle, rather than retrieving the limiting
value of that resource limit instance.
Given these are exactly the same and only differ on returned values, we
can extract the existing code for svcGetResourceLimitLimitValue() to
handle both values.
This kernel service function retrieves the maximum allowable value for
a provided resource category for a given resource limit instance. Given
we already have the functionality added to the resource limit instance
itself, it's sufficient to just hook it up.
The error scenarios for this are:
1. If an invalid resource category type is provided, then ERR_INVALID_ENUM is returned.
2. If an invalid handle is provided, then ERR_INVALID_HANDLE is returned (bad thing goes in, bad thing goes out, as one would expect).
If neither of the above error cases occur, then the out parameter is
provided with the maximum limit value for the given category and success
is returned.
This function simply creates a ResourceLimit instance and attempts to
create a handle for it within the current process' handle table. If the
kernal fails to either create the ResourceLimit instance or create a
handle for the ResourceLimit instance, it returns a failure code
(OUT_OF_RESOURCE, and HANDLE_TABLE_FULL respectively). Finally, it exits
by providing the output parameter with the handle value for the
ResourceLimit instance and returning that it was successful.
Note: We do not return OUT_OF_RESOURCE because, if yuzu runs out of
available memory, then new will currently throw. We *could* allocate the
kernel instance with std::nothrow, however this would be inconsistent
with how all other kernel objects are currently allocated.
Cleans out the citra/3DS-specific implementation details that don't
apply to the Switch. Sets the stage for implementing ResourceLimit
instances properly.
While we're at it, remove the erroneous checks within CreateThread() and
SetThreadPriority(). While these are indeed checked in some capacity,
they are not checked via a ResourceLimit instance.
In the process of moving out Citra-specifics, this also replaces the
system ResourceLimit instance's values with ones from the Switch.
Both member functions assume the passed in target process will not be
null. Instead of making this assumption implicit, we can change the
functions to be references and enforce this at the type-system level.
Similar to PR 1706, which cleans up the error codes for the filesystem
code, but done for the kernel error codes. This removes the ErrCodes
namespace and specifies the errors directly. This also fixes up any
straggling lines of code that weren't using the named error codes where
applicable.
* svcBreak now dumps information from the debug buffer passed
info1 and info2 seem to somtimes hold an address to a buffer, this is usually 4 bytes or the size of the int and contains an error code. There's other circumstances where it can be something different so we hexdump these to examine them at a later date.
* Addressed comments
All priority checks are supposed to occur before checking the validity
of the thread handle, we're also not supposed to return
ERR_NOT_AUTHORIZED here.
In the kernel, there isn't a singular handle table that everything gets
tossed into or used, rather, each process gets its own handle table that
it uses. This currently isn't an issue for us, since we only execute one
process at the moment, but we may as well get this out of the way so
it's not a headache later on.
