From 7fe27de26e341651a47f540e3ae0be46ed9ec974 Mon Sep 17 00:00:00 2001 From: Lioncash Date: Sun, 2 Dec 2018 02:00:11 -0500 Subject: 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 T* Lookup(Handle handle) { if (handle == PSEUDO_HANDLE_CURRENT_PROCESS) { return CurrentProcess(); } if (handle == PSUEDO_HANDLE_CURRENT_THREAD) { return CurrentThread(); } return static_cast(&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. --- src/core/hle/kernel/svc.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/core/hle/kernel') diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp index 2a7477247..aafd16800 100644 --- a/src/core/hle/kernel/svc.cpp +++ b/src/core/hle/kernel/svc.cpp @@ -705,7 +705,8 @@ static ResultCode GetInfo(u64* result, u64 info_id, u64 handle, u64 info_sub_id) return ERR_INVALID_ENUM_VALUE; } - const auto* process = Core::CurrentProcess(); + const auto& current_process_handle_table = Core::CurrentProcess()->GetHandleTable(); + const auto process = current_process_handle_table.Get(static_cast(handle)); if (!process) { return ERR_INVALID_HANDLE; } -- cgit v1.2.3