no more recursive locks

wakeup1() assumes you hold proc_table_lock
sleep(chan, lock) provides atomic sleep-and-release to wait for condition
ugly code in swtch/scheduler to implement new sleep
fix lots of bugs in pipes, wait, and exit
fix bugs if timer interrupt goes off in schedule()
console locks per line, not per byte

1 files changed, 23 insertions, 3 deletions

diff --git a/trap.c b/trap.c
index 6f5409b..66b15e0 100644
--- a/trap.c
+++ b/trap.c
@@ -36,8 +36,14 @@ trap(struct Trapframe *tf)
 {
   int v = tf->tf_trapno;
 
+  if(cpus[cpu()].clis){
+    cprintf("cpu %d v %d eip %x\n", cpu(), v, tf->tf_eip);
+    panic("interrupt while interrupts are off");
+  }
+
   if(v == T_SYSCALL){
     struct proc *cp = curproc[cpu()];
+    int num = cp->tf->tf_regs.reg_eax;
     if(cp == 0)
       panic("syscall with no proc");
     if(cp->killed)
@@ -50,6 +56,14 @@ trap(struct Trapframe *tf)
       panic("trap ret but not RUNNING");
     if(tf != cp->tf)
       panic("trap ret wrong tf");
+    if(cp->locks){
+      cprintf("num=%d\n", num);
+      panic("syscall returning locks held");
+    }
+    if(cpus[cpu()].clis)
+      panic("syscall returning but clis != 0");
+    if((read_eflags() & FL_IF) == 0)
+      panic("syscall returning but FL_IF clear");
     if(read_esp() < (unsigned)cp->kstack ||
        read_esp() >= (unsigned)cp->kstack + KSTACKSIZE)
       panic("trap ret esp wrong");
@@ -61,14 +75,20 @@ trap(struct Trapframe *tf)
   if(v == (IRQ_OFFSET + IRQ_TIMER)){
     struct proc *cp = curproc[cpu()];
     lapic_timerintr();
+    if(cp && cp->locks)
+      panic("timer interrupt while holding a lock");
     if(cp){
-      if(cpus[cpu()].clis != 0)
-        panic("trap clis > 0");
+#if 1
+      if((read_eflags() & FL_IF) == 0)
+        panic("timer interrupt but interrupts now disabled");
+#else
       cpus[cpu()].clis += 1;
       sti();
+#endif
       if(cp->killed)
         proc_exit();
-      yield();
+      if(cp->state == RUNNING)
+        yield();
     }
     return;
   }