citra/src/core/hle
Lioncash 7fe27de26e svc: Use the current process' handle table for retrieving the process instance to act upon
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.
2018-12-02 03:41:49 -05:00
..
kernel svc: Use the current process' handle table for retrieving the process instance to act upon 2018-12-02 03:41:49 -05:00
service service/set: Convert GetLanguageCode over to using PushEnum() 2018-11-30 09:08:07 -05:00
ipc_helpers.h hle_ipc: Add member function for querying the existence of a domain header 2018-10-29 23:28:04 -04:00
ipc.h kernel/errors: Remove now-unused, unnecessary, error codes 2018-10-24 14:58:37 -04:00
lock.cpp Fix build on macOS and linux 2018-01-13 22:38:52 +00:00
lock.h
result.h file_sys/errors: Extract FS-related error codes to file_sys/errors.h 2018-11-16 00:13:50 -05:00