kernel: Run the init function in a separate block to free everything before kernel_exit is called

Closes #40.

kernel/src/main.cpp

@@ -32,6 +32,7 @@ void reap_thread()
 }
 
 [[noreturn]] void init()
+{
     {
         kinfoln("Starting Moon %s %s", MOON_VERSION, MOON_RELEASE);
 
@@ -50,8 +51,8 @@ void reap_thread()
 
         auto init =
             mark_critical(VFS::resolve_path("/bin/preinit", Credentials {}), "Can't find init in the initial ramfs!");
-    auto init_thread =
-        mark_critical(Scheduler::new_userspace_thread(init, "/bin/preinit"), "Failed to create PID 1 process for init");
+        auto init_thread = mark_critical(Scheduler::new_userspace_thread(init, "/bin/preinit"),
+                                         "Failed to create PID 1 process for init");
 
         auto reap = mark_critical(Scheduler::new_kernel_thread(reap_thread, "[reap]"),
                                   "Failed to create the process reaper kernel thread");
@@ -65,6 +66,7 @@ void reap_thread()
         setup_log(log_debug_enabled(), log_serial_enabled(), false);
 
         init_thread->wake_up();
+    }
 
     kernel_exit();
 }

kernel/src/net/UnixSocket.cpp

@@ -143,10 +143,13 @@ Result<void> UnixSocket::connect(Registers* regs, int flags, struct sockaddr* ad
         m_blocked_thread = nullptr;
         if (current->interrupted)
         {
-            if (current->will_invoke_signal_handler()) return err(EINTR);
+            if (current->will_ignore_pending_signal())
+            {
                 current->process_pending_signals(regs);
                 continue;
             }
+            return err(EINTR);
+        }
         break;
     }
 
@@ -182,10 +185,13 @@ Result<SharedPtr<OpenFileDescription>> UnixSocket::accept(Registers* regs, int f
         m_blocked_thread = nullptr;
         if (current->interrupted)
         {
-            if (current->will_invoke_signal_handler()) return err(EINTR);
+            if (current->will_ignore_pending_signal())
+            {
                 current->process_pending_signals(regs);
                 continue;
             }
+            return err(EINTR);
+        }
     }
 
     check(peer);

kernel/src/sys/file.cpp

@@ -35,8 +35,12 @@ Result<u64> sys_read(Registers* regs, SyscallArgs args)
         if (current->interrupted)
         {
             kdbgln("signal: read interrupted by signal");
-            if (current->will_invoke_signal_handler()) return err(EINTR);
+            if (current->will_ignore_pending_signal())
+            {
                 current->process_pending_signals(regs);
+                continue;
+            }
+            return err(EINTR);
         }
     }
 

kernel/src/sys/poll.cpp

@@ -5,7 +5,7 @@
 #include "thread/Scheduler.h"
 #include <bits/poll.h>
 
-Result<u64> sys_poll(Registers* regs, SyscallArgs args)
+Result<u64> sys_poll(Registers*, SyscallArgs args)
 {
     struct pollfd* fds = (struct pollfd*)args[0];
     nfds_t nfds = (nfds_t)args[1];
@@ -58,8 +58,6 @@ Result<u64> sys_poll(Registers* regs, SyscallArgs args)
             {
                 guard.deactivate();
                 free_impl(kfds);
-                if (current->will_invoke_signal_handler()) return err(EINTR);
-                current->process_pending_signals(regs);
                 return err(EINTR);
             }
             continue;

kernel/src/sys/waitpid.cpp

@@ -27,10 +27,13 @@ Result<u64> sys_waitpid(Registers* regs, SyscallArgs args)
         if (current->interrupted)
         {
             kdbgln("signal: waitpid interrupted by signal");
-            if (current->will_invoke_signal_handler()) return err(EINTR);
+            if (current->will_ignore_pending_signal())
+            {
                 current->process_pending_signals(regs);
                 goto wait_for_child;
             }
+            return err(EINTR);
+        }
 
         check(thread->state == ThreadState::Exited);
     }
@@ -48,10 +51,13 @@ Result<u64> sys_waitpid(Registers* regs, SyscallArgs args)
             if (current->interrupted)
             {
                 kdbgln("signal: waitpid interrupted by signal");
-                if (current->will_invoke_signal_handler()) return err(EINTR);
+                if (current->will_ignore_pending_signal())
+                {
                     current->process_pending_signals(regs);
                     goto wait_for_any_child;
                 }
+                return err(EINTR);
+            }
 
             check(current->child_being_waited_for.value_or(-1) != -1);
 

kernel/src/thread/Thread.cpp

@@ -186,18 +186,19 @@ void Thread::process_pending_signals(Registers* current_regs)
     }
 }
 
-bool Thread::will_invoke_signal_handler()
+bool Thread::will_ignore_pending_signal()
 {
     for (int i = 0; i < NSIG; i++)
     {
         if (pending_signals & (1 << i))
         {
             int signo = i + 1;
-            if (signo != SIGKILL && signo != SIGSTOP && signal_mask & (1 << i)) continue;
-            auto handler = signal_handlers[i];
-            if (handler.sa_handler == SIG_IGN || handler.sa_handler == SIG_DFL) return false;
             if (signo == SIGKILL || signo == SIGSTOP) return false;
-            return true;
+            if (signal_mask & (1 << 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;
+            return false;
         }
     }
     return false;

kernel/src/thread/Thread.h

@@ -159,7 +159,7 @@ struct Thread : public LinkedListNode<Thread>
 
     void process_pending_signals(Registers* current_regs);
 
-    bool will_invoke_signal_handler();
+    bool will_ignore_pending_signal();
 
     bool deliver_signal(int signo, Registers* current_regs);
     void sigreturn(Registers* current_regs);

libc/src/stdio.cpp

@@ -135,6 +135,8 @@ static ssize_t read_data_into_buffer(FILE* stream)
     stream->_buf.index = 0;
     ssize_t nread = read(stream->_fd, stream->_buf.buffer, stream->_buf.capacity);
     if (nread >= 0) stream->_buf.size = nread;
+    else
+        stream->_buf.size = 0;
     stream->_buf.status |= FileStatusFlags::LastRead;
     return nread;
 }