mirror of
https://github.com/SerenityOS/serenity
synced 2024-10-02 22:24:26 +00:00
a6a439243f
This step would ideally not have been necessary (increases amount of refactoring and templates necessary, which in turn increases build times), but it gives us a couple of nice properties: - SpinlockProtected inside Singleton (a very common combination) can now obtain any lock rank just via the template parameter. It was not previously possible to do this with SingletonInstanceCreator magic. - SpinlockProtected's lock rank is now mandatory; this is the majority of cases and allows us to see where we're still missing proper ranks. - The type already informs us what lock rank a lock has, which aids code readability and (possibly, if gdb cooperates) lock mismatch debugging. - The rank of a lock can no longer be dynamic, which is not something we wanted in the first place (or made use of). Locks randomly changing their rank sounds like a disaster waiting to happen. - In some places, we might be able to statically check that locks are taken in the right order (with the right lock rank checking implementation) as rank information is fully statically known. This refactoring even more exposes the fact that Mutex has no lock rank capabilites, which is not fixed here.
65 lines
1.9 KiB
C++
65 lines
1.9 KiB
C++
/*
|
|
* Copyright (c) 2021, Patrick Meyer <git@the-space.agency>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <Kernel/Locking/Spinlock.h>
|
|
#include <Kernel/Memory/AnonymousVMObject.h>
|
|
|
|
namespace Kernel {
|
|
|
|
// Note: These need to be kept in sync with Userland/Libraries/LibC/sys/kcov.h
|
|
typedef volatile u64 kcov_pc_t;
|
|
#define KCOV_ENTRY_SIZE sizeof(kcov_pc_t)
|
|
#define KCOV_MAX_ENTRIES (10 * 1024 * 1024)
|
|
|
|
/*
|
|
* One KCOVInstance is allocated per process, when the process opens /dev/kcov
|
|
* for the first time. At this point it is in state OPENED. When a thread in
|
|
* the same process then uses the KCOV_ENABLE ioctl on the block device, the
|
|
* instance enters state TRACING.
|
|
*
|
|
* A KCOVInstance in state TRACING can return to state OPENED by either the
|
|
* KCOV_DISABLE ioctl or by killing the thread. A KCOVInstance in state OPENED
|
|
* can return to state UNUSED only when the process dies. At this point
|
|
* KCOVDevice::free_process will delete the KCOVInstance.
|
|
*/
|
|
class KCOVInstance final {
|
|
public:
|
|
explicit KCOVInstance(ProcessID pid);
|
|
|
|
ErrorOr<void> buffer_allocate(size_t buffer_size_in_entries);
|
|
bool has_buffer() const { return m_buffer != nullptr; }
|
|
void buffer_add_pc(u64 pc);
|
|
|
|
enum State {
|
|
UNUSED = 0,
|
|
OPENED = 1,
|
|
TRACING = 2,
|
|
} m_state { UNUSED };
|
|
|
|
State state() const { return m_state; }
|
|
void set_state(State state) { m_state = state; }
|
|
|
|
Memory::VMObject* vmobject() { return m_vmobject; }
|
|
|
|
Spinlock<LockRank::None>& spinlock() { return m_lock; }
|
|
|
|
private:
|
|
ProcessID m_pid { 0 };
|
|
u64 m_buffer_size_in_entries { 0 };
|
|
size_t m_buffer_size_in_bytes { 0 };
|
|
kcov_pc_t* m_buffer { nullptr };
|
|
LockRefPtr<Memory::AnonymousVMObject> m_vmobject;
|
|
|
|
// Here to ensure it's not garbage collected at the end of open()
|
|
OwnPtr<Memory::Region> m_kernel_region;
|
|
|
|
Spinlock<LockRank::None> m_lock {};
|
|
};
|
|
|
|
}
|