Fix TSS kernel stack pointer switching

bin/shell/shell.c

@@ -4,12 +4,13 @@
 int
 main(int argc, const char *argv[])
 {
+    int i;
     char buf[256];
 
     fputs("Shell\n", stdout);
     while (1) {
 	fputs("> ", stdout);
-	fgets(buf, sizeof(buf), stdin);
+	//fgets(buf, sizeof(buf), stdin);
     }
 }
 

include/syscall.h

@@ -19,5 +19,8 @@ int SystemFlush(uint64_t fd);
 uint64_t SystemOpen(const char *path, uint64_t flags);
 int SystemClose(uint64_t fd);
 
+// Threads
+int SystemThreadSleep(uint64_t time);
+
 #endif /* __SYSCALL_H__ */
 

lib/libc/syscall.c

@@ -79,3 +79,9 @@ SystemClose(uint64_t fd)
     return syscall(SYSCALL_CLOSE, fd);
 }
 
+int
+SystemThreadSleep(uint64_t time)
+{
+    return syscall(SYSCALL_THREADSLEEP, time);
+}
+

sbin/init/init.c

@@ -8,10 +8,8 @@ main(int argc, const char *argv[])
 
     SystemSpawn("/bin/shell");
 
-    //while (1) { }
-
     while (1) {
-	asm volatile("int3");
+	SystemThreadSleep(0);
     }
 }
 

sys/amd64/machine.c

@@ -34,7 +34,7 @@ extern void Loader_LoadInit();
 
 static SegmentDescriptor GDT[MAX_CPUS][GDT_MAX];
 static PseudoDescriptor GDTDescriptor[MAX_CPUS];
-static TaskStateSegment64 TSS[MAX_CPUS];
+TaskStateSegment64 TSS[MAX_CPUS];
 
 static char df_stack[4096];
 

sys/amd64/thread.c

@@ -3,8 +3,10 @@
 #include <stdint.h>
 #include <string.h>
 
+#include <sys/kconfig.h>
 #include <sys/kassert.h>
 #include <sys/kmem.h>
+#include <sys/mp.h>
 #include <sys/thread.h>
 #include <machine/amd64.h>
 #include <machine/amd64op.h>
@@ -48,6 +50,8 @@ Thread_SetupKThread(Thread *thr, void (*f)(void *), void *arg)
     tf->rflags = RFLAGS_IF;
 }
 
+extern TaskStateSegment64 TSS[MAX_CPUS];
+
 void
 Thread_SwitchArch(Thread *oldthr, Thread *newthr)
 {
@@ -63,5 +67,8 @@ Thread_SwitchArch(Thread *oldthr, Thread *newthr)
 
     // Jump to trapframe
     switchstack(&oldthr->arch.rsp, newthr->arch.rsp);
+
+    // Set new RSP0
+    TSS[CPU()].rsp0 = oldthr->kstack + 4096;
 }
 

sys/kern/loader.c

@@ -147,6 +147,7 @@ void
 Loader_EnterUserLevel(void *arg)
 {
     TrapFrame tf;
+
     memset(&tf, 0, sizeof(tf));
     tf.ds = SEL_UDS | 3;
     tf.rip = (uint64_t)arg;
@@ -154,6 +155,7 @@ Loader_EnterUserLevel(void *arg)
     tf.rsp = 0x70000000 + PGSIZE;
     tf.ss = SEL_UDS | 3;
     tf.rflags = RFLAGS_IF;
+
     Trap_Pop(&tf);
 }
 

sys/kern/syscall.c

@@ -86,11 +86,11 @@ Syscall_Spawn(uint64_t user_path)
     handle = Console_OpenHandle();
     Handle_Add(thr, handle);
 
-    //Loader_Load(thr, file, pg, 1024);
+    Loader_Load(thr, file, pg, 1024);
 
     VFS_Close(file);
 
-    //Thread_SetRunnable(thr);
+    Thread_SetRunnable(thr);
 
     return 0;
 }
@@ -216,6 +216,15 @@ Syscall_Close(uint64_t fd)
     return (handle->close)(handle);
 }
 
+uint64_t
+Syscall_ThreadSleep(uint64_t time)
+{
+    // XXX: Support sleeping
+    Thread_Scheduler();
+
+    return 0;
+}
+
 uint64_t
 Syscall_Entry(uint64_t syscall, uint64_t a1, uint64_t a2,
 	      uint64_t a3, uint64_t a4, uint64_t a5)
@@ -249,6 +258,8 @@ Syscall_Entry(uint64_t syscall, uint64_t a1, uint64_t a2,
 	    return Syscall_Open(a1, a2);
 	case SYSCALL_CLOSE:
 	    return Syscall_Close(a1);
+	case SYSCALL_THREADSLEEP:
+	    return Syscall_ThreadSleep(a1);
 	default:
 	    return (uint64_t)-1;
     }

sys/kern/thread.c

@@ -7,6 +7,7 @@
 #include <sys/kconfig.h>
 #include <sys/kdebug.h>
 #include <sys/kmem.h>
+#include <sys/mp.h>
 #include <sys/spinlock.h>
 #include <sys/thread.h>
 
@@ -161,9 +162,13 @@ Thread_Scheduler()
     Spinlock_Unlock(&threadLock);
 }
 
+extern TaskStateSegment64 TSS[MAX_CPUS];
+
 void
 ThreadKThreadEntry(TrapFrame *tf)
 {
+    TSS[CPU()].rsp0 = curProc->kstack + 4096;
+
     Spinlock_Unlock(&threadLock);
 
     Trap_Pop(tf);
@@ -174,7 +179,7 @@ Debug_Threads(int argc, const char *argv[])
 {
     Thread *thr;
 
-    Spinlock_Lock(&threadLock);
+    //Spinlock_Lock(&threadLock);
 
     kprintf("Current: %016llx %d\n", curProc, curProc->ctxSwitches);
     TAILQ_FOREACH(thr, &threadQueue, schedQueue)
@@ -182,8 +187,15 @@ Debug_Threads(int argc, const char *argv[])
 	kprintf("Thread: %016llx %d\n", thr, thr->ctxSwitches);
     }
 
-    Spinlock_Unlock(&threadLock);
+    //Spinlock_Unlock(&threadLock);
 }
 
 REGISTER_DBGCMD(threads, "Display list of threads", Debug_Threads);
 
+void
+Debug_ThreadInfo(int argc, const char *argv[])
+{
+}
+
+REGISTER_DBGCMD(threadinfo, "Display thread state", Debug_ThreadInfo);
+