We can hide the direct array from external view and instead provide
functions to retrieve the necessary info. This has the benefit of
completely hiding the makeup of the SinkDetails structure from the rest
of the code.
Given that this makes the array hidden, we can also make the array
constexpr by altering the members slightly. This gets rid of several
static constructor calls related to std::vector and std::function.
Now we don't have heap allocations here that need to occur before the
program can even enter main(). It also has the benefit of saving a
little bit of heap space, but this doesn't matter too much, since the
savings in that regard are pretty tiny.
Services created with the ServiceFramework base class install themselves as HleHandlers with an owning shared_ptr in the ServerPort ServiceFrameworkBase::port member variable, creating a cyclic ownership between ServiceFrameworkBase and the ServerPort, preventing deletion of the service objects.
Fix that by removing the ServiceFrameworkBase::port member because that was only used to detect multiple attempts at installing a port. Instead store a flag if the port was already installed to achieve the same functionality.
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.
This would result in svcSetMemoryAttribute getting the wrong value for
its third parameter. This is currently fine, given the service function
is stubbed, however this will be unstubbed in a future change, so this
needs to change.
The kernel returns a memory info instance with the base address set to
the end of the address space, and the size of said block as
0 - address_space_end, it doesn't set both of said members to zero.
Gets the two structures out of an unrelated header and places them with
the rest of the memory management code.
This also corrects the structures. PageInfo appears to only contain a
32-bit flags member, and the extra padding word in MemoryInfo isn't
necessary.
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.
fmt::format() returns a std::string instance by value, so calling
.c_str() on it here is equivalent to doing:
auto* ptr = std::string{}.c_str();
The data being pointed to isn't guaranteed to actually be valid anymore
after that expression ends. Instead, we can just take the string as is,
and provide the necessary formatting parameters.
David Marcec