kernel: Disable UBSAN in debug.cmake

UBSAN seems to bloat the kernel too much, so let's make debug.cmake actually usable for debugging by commenting it out.

kernel/debug.cmake

@@ -12,4 +12,4 @@ target_compile_definitions(moon PRIVATE DEVICE_REGISTRY_DEBUG)
 target_compile_definitions(moon PRIVATE FORK_DEBUG)
 target_compile_definitions(moon PRIVATE MOUNT_DEBUG)
 target_compile_definitions(moon PRIVATE CACHE_DEBUG)
-target_compile_options(moon PRIVATE -fsanitize=undefined)
+#target_compile_options(moon PRIVATE -fsanitize=undefined)

kernel/src/arch/x86_64/Thread.cpp

@@ -15,7 +15,7 @@ void Thread::set_ip(u64 ip)
     regs.rip = ip;
 }
 
-u64 Thread::ip()
+u64 Thread::ip() const
 {
     return regs.rip;
 }
@@ -25,7 +25,7 @@ void Thread::set_sp(u64 sp)
     regs.rsp = sp;
 }
 
-u64 Thread::sp()
+u64 Thread::sp() const
 {
     return regs.rsp;
 }

kernel/src/sys/exec.cpp

@@ -243,7 +243,7 @@ Result<u64> sys_fork(Registers* regs, SyscallArgs)
     Scheduler::add_process(process);
 
 #ifdef FORK_DEBUG
-    kdbgln("fork: thread %d forked into child %d", current->id, thread->id);
+    kdbgln("fork: thread %d forked into child %d", current->id, process->id);
 #endif
 
     return process->id;

kernel/src/thread/Scheduler.cpp

@@ -251,7 +251,7 @@ namespace Scheduler
         CPU::disable_interrupts();
 
 #ifdef REAP_DEBUG
-        kdbgln("reap: reaping thread with id %d", thread->id);
+        kdbgln("reap: reaping thread with id %d", thread->tid);
 #endif
 
         if (thread->is_kernel)
@@ -409,6 +409,16 @@ namespace Scheduler
         return {};
     }
 
+    Option<Thread*> find_by_tid(pid_t tid)
+    {
+        for (auto* const thread : g_threads)
+        {
+            if (thread->tid == tid) return thread;
+        }
+
+        return {};
+    }
+
     bool has_children(Process* process)
     {
         bool result { false };
@@ -447,8 +457,9 @@ namespace Scheduler
 
         for (const auto* thread : g_threads)
         {
-            kdbgln("Thread %p (belongs to pid %4d) %c [%-20s] %4d, state = %d", thread, thread->process->id,
-                   thread->is_kernel ? 'k' : 'u', thread->cmdline.chars(), thread->tid, (int)thread->state);
+            kdbgln("Thread %p (belongs to pid %4d) %c [%-20s] %4d, state = %d, ip = %p", thread, thread->process->id,
+                   thread->is_kernel ? 'k' : 'u', thread->cmdline.chars(), thread->tid, (int)thread->state,
+                   (void*)thread->ip());
         }
 
         for (const auto* process : g_processes)

kernel/src/thread/Scheduler.h

@@ -38,6 +38,7 @@ namespace Scheduler
     LinkedList<Process> check_for_dead_processes();
 
     Option<Process*> find_by_pid(pid_t pid);
+    Option<Thread*> find_by_tid(pid_t tid);
 
     template <typename Callback> void for_each_child(Process* process, Callback callback)
     {

kernel/src/thread/Thread.h

@@ -198,10 +198,10 @@ struct Thread : public LinkedListNode<Thread>
     void set_arguments(u64 arg1, u64 arg2, u64 arg3, u64 arg4);
 
     void set_ip(u64 ip);
-    u64 ip();
+    u64 ip() const;
 
     void set_sp(u64 sp);
-    u64 sp();
+    u64 sp() const;
 
     void set_return(u64 ret);
     u64 return_register();