1 files changed, 2 insertions, 2 deletions
diff --git a/spinlock.c b/spinlock.c
index 68cfbe9..e668598 100644
--- a/spinlock.c
+++ b/spinlock.c
@@ -23,7 +23,7 @@ initlock(struct spinlock *lk, char *name)
 void
 acquire(struct spinlock *lk)
 {
-  pushcli();
+  pushcli(); // disable interrupts to avoid deadlock.
   if(holding(lk))
     panic("acquire");
 
@@ -71,7 +71,7 @@ getcallerpcs(void *v, uint pcs[])
   
   ebp = (uint*)v - 2;
   for(i = 0; i < 10; i++){
-    if(ebp == 0 || ebp < (uint *) 0x100000 || ebp == (uint*)0xffffffff)
+    if(ebp == 0 || ebp < (uint*)0x100000 || ebp == (uint*)0xffffffff)
       break;
     pcs[i] = ebp[1];     // saved %eip
     ebp = (uint*)ebp[0]; // saved %ebp