From 8fd2e874a3f6a71977cd47a89e1edc88968a18c3 Mon Sep 17 00:00:00 2001
From: "akw27@boulderdash.cl.cam.ac.uk" <akw27@boulderdash.cl.cam.ac.uk>
Date: Wed, 29 Jan 2003 08:59:21 +0000
Subject: [PATCH] bitkeeper revision 1.15.3.1 (3e3797e9gMcow8ShTTrYuWSeSSe-BA)

protect free_list with a spin lock.
---
 xen-2.4.16/common/domain.c   | 5 +++++
 xen-2.4.16/common/memory.c   | 4 ++++
 xen-2.4.16/include/xeno/mm.h | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/xen-2.4.16/common/domain.c b/xen-2.4.16/common/domain.c
index 1128cdfa15..fc71bad3ef 100644
--- a/xen-2.4.16/common/domain.c
+++ b/xen-2.4.16/common/domain.c
@@ -334,10 +334,13 @@ static unsigned int alloc_new_dom_mem(struct task_struct *p, unsigned int kbytes
     struct pfn_info *pf, *pf_head;
     unsigned int alloc_pfns;
     unsigned int req_pages;
+    unsigned long flags;
 
     /* how many pages do we need to alloc? */
     req_pages = kbytes >> (PAGE_SHIFT - 10);
 
+    spin_lock_irqsave(&free_list_lock, flags);
+    
     /* is there enough mem to serve the request? */   
     if(req_pages > free_pfns)
         return -1;
@@ -369,6 +372,8 @@ static unsigned int alloc_new_dom_mem(struct task_struct *p, unsigned int kbytes
 
         free_pfns--;
     }
+   
+    spin_unlock_irqrestore(&free_list_lock, flags);
     
     p->tot_pages = req_pages;
 
diff --git a/xen-2.4.16/common/memory.c b/xen-2.4.16/common/memory.c
index 2e6697a0b8..8cbed41416 100644
--- a/xen-2.4.16/common/memory.c
+++ b/xen-2.4.16/common/memory.c
@@ -206,6 +206,7 @@ unsigned long frame_table_size;
 unsigned long max_page;
 
 struct list_head free_list;
+spinlock_t free_list_lock = SPIN_LOCK_UNLOCKED;
 unsigned int free_pfns;
 
 static int tlb_flush[NR_CPUS];
@@ -219,6 +220,7 @@ void __init init_frametable(unsigned long nr_pages)
 {
     struct pfn_info *pf;
     unsigned long page_index;
+    unsigned long flags;
 
     memset(tlb_flush, 0, sizeof(tlb_flush));
 
@@ -232,6 +234,7 @@ void __init init_frametable(unsigned long nr_pages)
     memset(frame_table, 0, frame_table_size);
 
     /* Put all domain-allocatable memory on a free list. */
+    spin_lock_irqsave(&free_list_lock, flags);
     INIT_LIST_HEAD(&free_list);
     for( page_index = (MAX_MONITOR_ADDRESS + frame_table_size) >> PAGE_SHIFT; 
          page_index < nr_pages; 
@@ -240,6 +243,7 @@ void __init init_frametable(unsigned long nr_pages)
         pf = list_entry(&frame_table[page_index].list, struct pfn_info, list);
         list_add_tail(&pf->list, &free_list);
     }
+    spin_unlock_irqrestore(&free_list_lock, flags);
 }
 
 
diff --git a/xen-2.4.16/include/xeno/mm.h b/xen-2.4.16/include/xeno/mm.h
index 30071e76cf..3d014f650b 100644
--- a/xen-2.4.16/include/xeno/mm.h
+++ b/xen-2.4.16/include/xeno/mm.h
@@ -7,6 +7,7 @@
 #include <asm/desc.h>
 #include <xeno/list.h>
 #include <hypervisor-ifs/hypervisor-if.h>
+#include <xeno/spinlock.h>
 
 /* XXX KAF: These may die eventually, but so many refs in slab.c :((( */
 
@@ -110,6 +111,7 @@ typedef struct pfn_info {
 extern frame_table_t * frame_table;
 extern unsigned long frame_table_size;
 extern struct list_head free_list;
+extern spinlock_t free_list_lock;
 extern unsigned int free_pfns;
 extern unsigned long max_page;
 void init_frametable(unsigned long nr_pages);
-- 
2.30.2