From 5be0039ce9e22f140a29e167526c64c723c5be3c Mon Sep 17 00:00:00 2001
From: rtm <rtm>
Date: Thu, 10 Aug 2006 22:08:14 +0000
Subject: interrupts could be recursive since lapic_eoi() called before rti so
 fast interrupts overflow the kernel stack fix: cli() before lapic_eoi()

---
 trap.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

(limited to 'trap.c')

diff --git a/trap.c b/trap.c
index b172a77..99aaa70 100644
--- a/trap.c
+++ b/trap.c
@@ -41,6 +41,17 @@ trap(struct trapframe *tf)
     panic("interrupt while holding a lock");
   }
 
+  if(cpu() == 1 && curproc[cpu()] == 0){
+    if(&tf < cpus[cpu()].mpstack || &tf > cpus[cpu()].mpstack + 512){
+      cprintf("&tf %x mpstack %x\n", &tf, cpus[cpu()].mpstack);
+      panic("trap cpu stack");
+    }
+  } else if(curproc[cpu()]){
+    if(&tf < curproc[cpu()]->kstack){
+      panic("trap kstack");
+    }
+  }
+
   if(v == T_SYSCALL){
     struct proc *cp = curproc[cpu()];
     int num = cp->tf->eax;
@@ -97,11 +108,20 @@ trap(struct trapframe *tf)
 
   if(v == (IRQ_OFFSET + IRQ_IDE)){
     ide_intr();
+    if(cpus[cpu()].nlock)
+      panic("ide_intr returned while holding a lock");
+    cli(); // prevent a waiting interrupt from overflowing stack
+    lapic_eoi();
     return;
   }
 
   if(v == (IRQ_OFFSET + IRQ_KBD)){
     kbd_intr();
+    if(cpus[cpu()].nlock){
+      panic("kbd_intr returned while holding a lock");
+    }
+    cli(); // prevent a waiting interrupt from overflowing stack
+    lapic_eoi();
     return;
   }
 
-- 
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