interrupts could be recursive since lapic_eoi() called before rti

so fast interrupts overflow the kernel stack
fix: cli() before lapic_eoi()

1 files changed, 14 insertions, 2 deletions

diff --git a/proc.c b/proc.c
index 0254c2e..5f8769b 100644
--- a/proc.c
+++ b/proc.c
@@ -7,7 +7,7 @@
 #include "defs.h"
 #include "spinlock.h"
 
-struct spinlock proc_table_lock = { "proc_table" };
+struct spinlock proc_table_lock;
 
 struct proc proc[NPROC];
 struct proc *curproc[NCPU];
@@ -15,6 +15,12 @@ int next_pid = NCPU;
 extern void forkret(void);
 extern void forkret1(struct trapframe*);
 
+void
+pinit(void)
+{
+  initlock(&proc_table_lock, "proc_table");
+}
+
 /*
  * set up a process's task state and segment descriptors
  * correctly, given its current size and address in memory.
@@ -146,6 +152,9 @@ scheduler(void)
     // Loop over process table looking for process to run.
     acquire(&proc_table_lock);
     for(i = 0; i < NPROC; i++){
+      if(cpus[cpu()].guard1 != 0xdeadbeef || 
+         cpus[cpu()].guard2 != 0xdeadbeef)
+        panic("cpu guard");
       p = &proc[i];
       if(p->state != RUNNABLE)
         continue;
@@ -194,6 +203,7 @@ scheduler(void)
 
       // XXX if not holding proc_table_lock panic.
     }
+
     release(&proc_table_lock);
     
     if(cpus[cpu()].nlock != 0)
@@ -212,7 +222,9 @@ scheduler(void)
 void
 sched(void)
 {
-  if(setjmp(&curproc[cpu()]->jmpbuf) == 0)
+  struct proc *p = curproc[cpu()];
+
+  if(setjmp(&p->jmpbuf) == 0)
     longjmp(&cpus[cpu()].jmpbuf);
 }