From a3aa7aaf0be9d95766b9c123b7c32b6505084c3c Mon Sep 17 00:00:00 2001 From: Lioncash Date: Tue, 4 Dec 2018 18:54:18 -0500 Subject: [PATCH 1/3] kernel/readable_event: Add member function for enforcing a strict reset contract svcResetSignal relies on the event instance to have already been signaled before attempting to reset it. If this isn't the case, then an error code has to be returned. --- src/core/hle/kernel/readable_event.cpp | 12 +++++++++++- src/core/hle/kernel/readable_event.h | 11 +++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/src/core/hle/kernel/readable_event.cpp b/src/core/hle/kernel/readable_event.cpp index 92e16b4e6..ba01f495c 100644 --- a/src/core/hle/kernel/readable_event.cpp +++ b/src/core/hle/kernel/readable_event.cpp @@ -4,10 +4,10 @@ #include #include "common/assert.h" +#include "core/hle/kernel/errors.h" #include "core/hle/kernel/object.h" #include "core/hle/kernel/readable_event.h" #include "core/hle/kernel/thread.h" -#include "core/hle/kernel/writable_event.h" namespace Kernel { @@ -34,6 +34,16 @@ void ReadableEvent::Clear() { signaled = false; } +ResultCode ReadableEvent::Reset() { + if (!signaled) { + return ERR_INVALID_STATE; + } + + Clear(); + + return RESULT_SUCCESS; +} + void ReadableEvent::WakeupAllWaitingThreads() { WaitObject::WakeupAllWaitingThreads(); diff --git a/src/core/hle/kernel/readable_event.h b/src/core/hle/kernel/readable_event.h index 867ff3051..80b3b0aba 100644 --- a/src/core/hle/kernel/readable_event.h +++ b/src/core/hle/kernel/readable_event.h @@ -7,6 +7,8 @@ #include "core/hle/kernel/object.h" #include "core/hle/kernel/wait_object.h" +union ResultCode; + namespace Kernel { class KernelCore; @@ -39,8 +41,17 @@ public: void WakeupAllWaitingThreads() override; + /// Unconditionally clears the readable event's state. void Clear(); + /// Clears the readable event's state if and only if it + /// has already been signaled. + /// + /// @pre The event must be in a signaled state. If this event + /// is in an unsignaled state and this function is called, + /// then ERR_INVALID_STATE will be returned. + ResultCode Reset(); + private: explicit ReadableEvent(KernelCore& kernel); From c7462ce71241fe6c8dfee48a859c63a6b1fd84fb Mon Sep 17 00:00:00 2001 From: Lioncash Date: Tue, 4 Dec 2018 19:08:56 -0500 Subject: [PATCH 2/3] kernel/process: Make Process a WaitObject Process instances can be waited upon for state changes. This is also utilized by svcResetSignal, which will be modified in an upcoming change. This simply puts all of the WaitObject related machinery in place. --- src/core/hle/kernel/object.cpp | 2 +- src/core/hle/kernel/process.cpp | 42 ++++++++++++++++++++++++++++++--- src/core/hle/kernel/process.h | 30 +++++++++++++++++++++-- 3 files changed, 68 insertions(+), 6 deletions(-) diff --git a/src/core/hle/kernel/object.cpp b/src/core/hle/kernel/object.cpp index bb1b68778..0ea851a74 100644 --- a/src/core/hle/kernel/object.cpp +++ b/src/core/hle/kernel/object.cpp @@ -15,6 +15,7 @@ bool Object::IsWaitable() const { switch (GetHandleType()) { case HandleType::ReadableEvent: case HandleType::Thread: + case HandleType::Process: case HandleType::Timer: case HandleType::ServerPort: case HandleType::ServerSession: @@ -23,7 +24,6 @@ bool Object::IsWaitable() const { case HandleType::Unknown: case HandleType::WritableEvent: case HandleType::SharedMemory: - case HandleType::Process: case HandleType::AddressArbiter: case HandleType::ResourceLimit: case HandleType::ClientPort: diff --git a/src/core/hle/kernel/process.cpp b/src/core/hle/kernel/process.cpp index 4ecb8c926..211bf6686 100644 --- a/src/core/hle/kernel/process.cpp +++ b/src/core/hle/kernel/process.cpp @@ -9,6 +9,7 @@ #include "common/logging/log.h" #include "core/core.h" #include "core/file_sys/program_metadata.h" +#include "core/hle/kernel/errors.h" #include "core/hle/kernel/kernel.h" #include "core/hle/kernel/process.h" #include "core/hle/kernel/resource_limit.h" @@ -48,6 +49,21 @@ SharedPtr Process::GetResourceLimit() const { return resource_limit; } +ResultCode Process::ClearSignalState() { + if (status == ProcessStatus::Exited) { + LOG_ERROR(Kernel, "called on a terminated process instance."); + return ERR_INVALID_STATE; + } + + if (!is_signaled) { + LOG_ERROR(Kernel, "called on a process instance that isn't signaled."); + return ERR_INVALID_STATE; + } + + is_signaled = false; + return RESULT_SUCCESS; +} + void Process::LoadFromMetadata(const FileSys::ProgramMetadata& metadata) { program_id = metadata.GetTitleID(); is_64bit_process = metadata.Is64BitProgram(); @@ -137,13 +153,13 @@ void Process::Run(VAddr entry_point, s32 main_thread_priority, u32 stack_size) { .Unwrap(); vm_manager.LogLayout(); - status = ProcessStatus::Running; + ChangeStatus(ProcessStatus::Running); Kernel::SetupMainThread(kernel, entry_point, main_thread_priority, *this); } void Process::PrepareForTermination() { - status = ProcessStatus::Exited; + ChangeStatus(ProcessStatus::Exiting); const auto stop_threads = [this](const std::vector>& thread_list) { for (auto& thread : thread_list) { @@ -167,6 +183,8 @@ void Process::PrepareForTermination() { stop_threads(system.Scheduler(1).GetThreadList()); stop_threads(system.Scheduler(2).GetThreadList()); stop_threads(system.Scheduler(3).GetThreadList()); + + ChangeStatus(ProcessStatus::Exited); } /** @@ -265,7 +283,25 @@ ResultCode Process::UnmapMemory(VAddr dst_addr, VAddr /*src_addr*/, u64 size) { return vm_manager.UnmapRange(dst_addr, size); } -Kernel::Process::Process(KernelCore& kernel) : Object{kernel} {} +Kernel::Process::Process(KernelCore& kernel) : WaitObject{kernel} {} Kernel::Process::~Process() {} +void Process::Acquire(Thread* thread) { + ASSERT_MSG(!ShouldWait(thread), "Object unavailable!"); +} + +bool Process::ShouldWait(Thread* thread) const { + return !is_signaled; +} + +void Process::ChangeStatus(ProcessStatus new_status) { + if (status == new_status) { + return; + } + + status = new_status; + is_signaled = true; + WakeupAllWaitingThreads(); +} + } // namespace Kernel diff --git a/src/core/hle/kernel/process.h b/src/core/hle/kernel/process.h index 49345aa66..bcb9ac4b8 100644 --- a/src/core/hle/kernel/process.h +++ b/src/core/hle/kernel/process.h @@ -14,9 +14,10 @@ #include "common/bit_field.h" #include "common/common_types.h" #include "core/hle/kernel/handle_table.h" -#include "core/hle/kernel/object.h" #include "core/hle/kernel/thread.h" #include "core/hle/kernel/vm_manager.h" +#include "core/hle/kernel/wait_object.h" +#include "core/hle/result.h" namespace FileSys { class ProgramMetadata; @@ -117,7 +118,7 @@ struct CodeSet final { VAddr entrypoint = 0; }; -class Process final : public Object { +class Process final : public WaitObject { public: static constexpr std::size_t RANDOM_ENTROPY_SIZE = 4; @@ -212,6 +213,16 @@ public: return random_entropy.at(index); } + /// Clears the signaled state of the process if and only if it's signaled. + /// + /// @pre The process must not be already terminated. If this is called on a + /// terminated process, then ERR_INVALID_STATE will be returned. + /// + /// @pre The process must be in a signaled state. If this is called on a + /// process instance that is not signaled, ERR_INVALID_STATE will be + /// returned. + ResultCode ClearSignalState(); + /** * Loads process-specifics configuration info with metadata provided * by an executable. @@ -260,6 +271,17 @@ private: explicit Process(KernelCore& kernel); ~Process() override; + /// Checks if the specified thread should wait until this process is available. + bool ShouldWait(Thread* thread) const override; + + /// Acquires/locks this process for the specified thread if it's available. + void Acquire(Thread* thread) override; + + /// Changes the process status. If the status is different + /// from the current process status, then this will trigger + /// a process signal. + void ChangeStatus(ProcessStatus new_status); + /// Memory manager for this process. Kernel::VMManager vm_manager; @@ -305,6 +327,10 @@ private: /// specified by metadata provided to the process during loading. bool is_64bit_process = true; + /// Whether or not this process is signaled. This occurs + /// upon the process changing to a different state. + bool is_signaled = false; + /// Total running time for the process in ticks. u64 total_process_running_time_ticks = 0; From 2f253986df3e5cf5aca0bb2fcec2e23c0cab57d7 Mon Sep 17 00:00:00 2001 From: Lioncash Date: Tue, 4 Dec 2018 19:59:29 -0500 Subject: [PATCH 3/3] kernel/svc: Correct behavior of svcResetSignal() 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. --- src/core/hle/kernel/svc.cpp | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp index e6c77f9db..84df2040e 100644 --- a/src/core/hle/kernel/svc.cpp +++ b/src/core/hle/kernel/svc.cpp @@ -1433,17 +1433,24 @@ static ResultCode CloseHandle(Handle handle) { return handle_table.Close(handle); } -/// Reset an event +/// Clears the signaled state of an event or process. static ResultCode ResetSignal(Handle handle) { LOG_DEBUG(Kernel_SVC, "called handle 0x{:08X}", handle); const auto& handle_table = Core::CurrentProcess()->GetHandleTable(); + auto event = handle_table.Get(handle); + if (event) { + return event->Reset(); + } - ASSERT(event != nullptr); + auto process = handle_table.Get(handle); + if (process) { + return process->ClearSignalState(); + } - event->Clear(); - return RESULT_SUCCESS; + LOG_ERROR(Kernel_SVC, "Invalid handle (0x{:08X})", handle); + return ERR_INVALID_HANDLE; } /// Creates a TransferMemory object