libluna+kernel: Add Bitset and use it for signals

kernel/src/arch/x86_64/Thread.cpp

@@ -124,7 +124,7 @@ bool Thread::deliver_signal(int signo, Registers* current_regs)
     if (push_mem_on_stack((u8*)&handler.__sa_sigreturn, sizeof(void*)).has_error()) return false;
 
     signal_mask = handler.sa_mask;
-    if ((handler.sa_flags & SA_NODEFER) == 0) signal_mask |= (1 << (signo - 1));
+    if ((handler.sa_flags & SA_NODEFER) == 0) signal_mask.set(signo - 1, true);
 
     rsp = regs.rsp;
 

kernel/src/fs/devices/ConsoleDevice.cpp

@@ -36,7 +36,7 @@ Result<void> ConsoleDevice::handle_background_process_group(bool can_succeed, in
     auto* current = Scheduler::current();
     if (current->pgid == foreground_pgrp) return {};
 
-    if ((current->signal_mask & (1 << (signo - 1))) || (current->signal_handlers[signo - 1].sa_handler == SIG_IGN))
+    if ((current->signal_mask.get(signo - 1)) || (current->signal_handlers[signo - 1].sa_handler == SIG_IGN))
     {
         if (can_succeed) return {};
         return err(EIO);

kernel/src/sys/signal.cpp

@@ -79,7 +79,8 @@ Result<u64> sys_sigprocmask(Registers*, SyscallArgs args)
 
     if (oldset)
     {
-        if (!MemoryManager::copy_to_user_typed(oldset, &current->signal_mask)) return err(EFAULT);
+        sigset_t mask = current->signal_mask.value();
+        if (!MemoryManager::copy_to_user_typed(oldset, &mask)) return err(EFAULT);
     }
 
     if (set)
@@ -89,8 +90,8 @@ Result<u64> sys_sigprocmask(Registers*, SyscallArgs args)
 
         switch (how)
         {
-        case SIG_BLOCK: current->signal_mask |= kset; break;
-        case SIG_UNBLOCK: current->signal_mask &= ~kset; break;
+        case SIG_BLOCK: current->signal_mask = current->signal_mask.value() | kset; break;
+        case SIG_UNBLOCK: current->signal_mask = current->signal_mask.value() & ~kset; break;
         case SIG_SETMASK: current->signal_mask = kset; break;
         default: return err(EINVAL);
         }

kernel/src/thread/Thread.cpp

@@ -148,10 +148,10 @@ void Thread::process_pending_signals(Registers* current_regs)
     for (int i = 0; i < NSIG; i++)
     {
         int signo = i + 1;
-        if (signo != SIGKILL && signo != SIGSTOP && signal_mask & (1 << i)) continue;
-        if (pending_signals & (1 << i))
+        if (signo != SIGKILL && signo != SIGSTOP && signal_mask.get(i)) continue;
+        if (pending_signals.get(i))
         {
-            pending_signals &= ~(1 << i);
+            pending_signals.set(i, false);
             kinfoln("signal: executing signal %d for thread %d", signo, id);
             auto handler = signal_handlers[i];
             if (signo != SIGKILL && signo != SIGSTOP && handler.sa_handler == SIG_IGN)
@@ -190,11 +190,11 @@ bool Thread::will_ignore_pending_signal()
 {
     for (int i = 0; i < NSIG; i++)
     {
-        if (pending_signals & (1 << i))
+        if (pending_signals.get(i))
         {
             int signo = i + 1;
             if (signo == SIGKILL || signo == SIGSTOP) return false;
-            if (signal_mask & (1 << i)) continue;
+            if (signal_mask.get(i)) continue;
             auto handler = signal_handlers[i];
             if (handler.sa_handler == SIG_IGN) return true;
             if (handler.sa_handler == SIG_DFL && default_actions[i] == DefaultSignalAction::Ignore) return true;
@@ -209,7 +209,7 @@ void Thread::send_signal(int signo)
     if (is_kernel) return;
 
     check(signo > 0 && signo <= NSIG);
-    pending_signals |= 1 << (signo - 1);
+    pending_signals.set(signo - 1, true);
 
     if (state == ThreadState::Waiting || state == ThreadState::Sleeping)
     {

kernel/src/thread/Thread.h

@@ -4,6 +4,7 @@
 #include "fs/VFS.h"
 #include "memory/AddressSpace.h"
 #include <bits/signal.h>
+#include <luna/Bitset.h>
 #include <luna/LinkedList.h>
 #include <luna/OwnedPtr.h>
 #include <luna/Result.h>
@@ -105,8 +106,8 @@ struct Thread : public LinkedListNode<Thread>
                                                  SharedPtr<VFS::Inode>* parent_inode = nullptr);
 
     struct sigaction signal_handlers[NSIG];
-    sigset_t signal_mask { 0 };
-    sigset_t pending_signals { 0 };
+    Bitset<sigset_t> signal_mask { 0 };
+    Bitset<sigset_t> pending_signals { 0 };
     bool interrupted { false };
 
     bool unrestricted_task { false };

libluna/include/luna/Bitset.h

@@ -0,0 +1,58 @@
+#pragma once
+#include <luna/Check.h>
+
+template <typename T> class Bitset
+{
+  public:
+    Bitset() : m_value()
+    {
+    }
+
+    Bitset(T value) : m_value(value)
+    {
+    }
+
+    Bitset(const Bitset<T>& other) : m_value(other.m_value)
+    {
+    }
+
+    Bitset<T>& operator=(T value)
+    {
+        m_value = value;
+        return *this;
+    }
+
+    Bitset<T>& operator=(const Bitset<T>& other)
+    {
+        if (&other == this) return *this;
+        m_value = other.m_value;
+        return *this;
+    }
+
+    T value() const
+    {
+        return m_value;
+    }
+
+    void set(int index, bool b)
+    {
+        check((usize)index < (sizeof(T) * 8));
+        if (b) m_value |= (((T)1) << index);
+        else
+            m_value &= ~(((T)1) << index);
+    }
+
+    bool get(int index)
+    {
+        check((usize)index < (sizeof(T) * 8));
+        return m_value & (((T)1) << index);
+    }
+
+    void clear()
+    {
+        m_value = 0;
+    }
+
+  private:
+    T m_value;
+};