Merge branch exit_status into main

Reviewed-on: #8

apps/src/memeater.c

@@ -17,4 +17,5 @@ int main()
     } while ((allocated = malloc(CHUNK)));
     perror("malloc");
     printf("Press any key to restart.\n");
+    return 1;
 }

kernel/include/sys/Syscall.h

@@ -18,7 +18,7 @@ namespace Syscall
     void entry(Context* context);
 }
 
-void sys_exit(Context* context);
+void sys_exit(Context* context, int status);
 void sys_yield(Context* context);
 void sys_sleep(Context* context, uint64_t ms);
 void sys_write(Context* context, const char* addr, size_t size);

kernel/include/thread/Scheduler.h

@@ -5,15 +5,15 @@ namespace Scheduler
 {
     void init();
     void yield();
-    void exit();
+    void exit(int status);
     void sleep(unsigned long ms);
     void add_kernel_task(void (*task)(void));
     void add_user_task(void* task);
 
     void load_user_task(const char* filename);
 
-    void task_exit(Context* context);
-    void task_misbehave(Context* context);
+    void task_exit(Context* context, int64_t status);
+    void task_misbehave(Context* context, int64_t status);
 
     Task* current_task();
 

kernel/include/thread/Task.h

@@ -16,6 +16,9 @@ struct Task
     Context regs;
 
     int64_t task_sleep = 0;
+
+    int64_t exit_status;
+
     int64_t task_time = 0;
 
     Task* next_task = nullptr;

kernel/src/interrupts/Entry.cpp

@@ -34,7 +34,7 @@ extern "C" void common_handler(Context* context)
 
             StackTracer tracer(context->rbp);
             tracer.trace_with_ip(context->rip);
-            Scheduler::task_misbehave(context);
+            Scheduler::task_misbehave(context, -2);
         }
     }
     if (context->number == 14)
@@ -51,7 +51,7 @@ extern "C" void common_handler(Context* context)
             StackTracer tracer(context->rbp);
             tracer.trace_with_ip(context->rip);
 
-            Scheduler::task_misbehave(context);
+            Scheduler::task_misbehave(context, -3);
         }
     }
     if (context->number == 8) { int_panic(context, "Double fault, halting"); }

kernel/src/main.cpp

@@ -163,5 +163,5 @@ extern "C" void _start()
         kinfoln("Found PCI device %x:%x, %s", dev.id().vendor, dev.id().device, pci_type_name(dev.type()));
     });
 
-    Scheduler::exit();
+    Scheduler::exit(0);
 }

kernel/src/sys/Syscall.cpp

@@ -9,7 +9,7 @@ void Syscall::entry(Context* context)
     switch (context->rax)
     {
     case SYS_exit: // sys_exit
-        sys_exit(context);
+        sys_exit(context, (int)context->rdi);
         break;
     case SYS_yield: // sys_yield
         sys_yield(context);

kernel/src/sys/sched.cpp

@@ -1,8 +1,8 @@
 #include "thread/Scheduler.h"
 
-void sys_exit(Context* context)
+void sys_exit(Context* context, int status)
 {
-    Scheduler::task_exit(context);
+    Scheduler::task_exit(context, status);
 }
 
 void sys_yield(Context* context)

kernel/src/thread/Scheduler.cpp

@@ -153,7 +153,7 @@ void Scheduler::reap_task(Task* task)
     task_num--;
     Task* exiting_task = task;
     ASSERT(task->id != 0); // WHY IN THE WORLD WOULD WE BE REAPING THE IDLE TASK?
-    kinfoln("reaping task %ld", exiting_task->id);
+    kinfoln("reaping task %ld, exited with code %ld", exiting_task->id, exiting_task->exit_status);
     if (exiting_task->allocated_stack)
         MemoryManager::release_pages((void*)exiting_task->allocated_stack, TASK_PAGES_IN_STACK);
     if (exiting_task->image)
@@ -168,20 +168,22 @@ void Scheduler::reap_task(Task* task)
     delete exiting_task;
 }
 
-void Scheduler::task_exit(Context* context)
+void Scheduler::task_exit(Context* context, int64_t status)
 {
     ASSERT(Interrupts::is_in_handler());
     kdbgln("exit: task %ld finished running, used %ld ms of cpu time", sched_current_task->id,
            sched_current_task->cpu_time);
     sched_current_task->state = sched_current_task->Exited;
+    sched_current_task->exit_status = status;
     task_yield(context);
 }
 
-void Scheduler::task_misbehave(Context* context)
+void Scheduler::task_misbehave(Context* context, int64_t status)
 {
     ASSERT(Interrupts::is_in_handler());
     kdbgln("exit: task %ld misbehaved, used %ld ms of cpu time", sched_current_task->id, sched_current_task->cpu_time);
     sched_current_task->state = sched_current_task->Exited;
+    sched_current_task->exit_status = status;
     task_yield(context);
 }
 
@@ -311,9 +313,9 @@ void Scheduler::yield()
     asm volatile("int $0x42" : : "a"(1));
 }
 
-void Scheduler::exit()
+void Scheduler::exit(int status)
 {
-    asm volatile("int $0x42" : : "a"(0));
+    asm volatile("int $0x42" : : "a"(0), "D"(status));
 }
 
 void Scheduler::sleep(unsigned long ms)

libs/libc/src/stdlib.cpp

@@ -15,9 +15,9 @@ extern "C"
         exit(-1);
     }
 
-    noreturn void exit(int)
+    noreturn void exit(int status)
     {
-        syscall(SYS_exit);
+        syscall(SYS_exit, status);
         __builtin_unreachable();
     }
 

libs/libc/src/unistd.cpp

@@ -31,10 +31,10 @@ extern "C"
         va_start(ap, number);
         switch (number)
         {
-        case SYS_exit:
         case SYS_yield:
         case SYS_gettid:
         case SYS_rand: result = __luna_syscall0(number); break;
+        case SYS_exit:
         case SYS_sleep: result = __luna_syscall1(number, va_arg(ap, arg)); break;
         case SYS_write:
         case SYS_munmap: