bitkeeper revision 1.1159.194.1 (41a5c5c5J8BRAOOMMsDGqEcd_8brmg)

Sort exception tables during Xen boot. This will fix some nasty crashes
that some people have seen in the last day or so.

xen/arch/x86/extable.c

@@ -3,6 +3,36 @@
 #include <xen/spinlock.h>
 #include <asm/uaccess.h>
 
+extern struct exception_table_entry __start___ex_table[];
+extern struct exception_table_entry __stop___ex_table[];
+extern struct exception_table_entry __start___pre_ex_table[];
+extern struct exception_table_entry __stop___pre_ex_table[];
+
+static void sort_exception_table(struct exception_table_entry *start,
+                                 struct exception_table_entry *end)
+{
+    struct exception_table_entry *p, *q, tmp;
+
+    for ( p = start; p < end; p++ )
+    {
+        for ( q = p-1; q > start; q-- )
+            if ( p->insn > q->insn )
+                break;
+        if ( ++q != p )
+        {
+            tmp = *p;
+            memmove(q+1, q, (p-q)*sizeof(*p));
+            *q = tmp;
+        }
+    }
+}
+
+void sort_exception_tables(void)
+{
+    sort_exception_table(__start___ex_table, __stop___ex_table);
+    sort_exception_table(__start___pre_ex_table, __stop___pre_ex_table);
+}
+
 static inline unsigned long
 search_one_table(const struct exception_table_entry *first,
 		 const struct exception_table_entry *last,
@@ -28,21 +58,15 @@ search_one_table(const struct exception_table_entry *first,
 unsigned long
 search_exception_table(unsigned long addr)
 {
-    extern const struct exception_table_entry __start___ex_table[];
-    extern const struct exception_table_entry __stop___ex_table[];
     return search_one_table(
         __start___ex_table, __stop___ex_table-1, addr);
 }
 
-#ifdef __i386__
 unsigned long
 search_pre_exception_table(unsigned long addr)
 {
-    extern const struct exception_table_entry __start___pre_ex_table[];
-    extern const struct exception_table_entry __stop___pre_ex_table[];
     unsigned long fixup = search_one_table(
         __start___pre_ex_table, __stop___pre_ex_table-1, addr);
     DPRINTK("Pre-exception: %08lx -> %08lx\n", addr, fixup);
     return fixup;
 }
-#endif

xen/arch/x86/setup.c

@@ -326,6 +326,8 @@ void __init start_of_day(void)
     if ( opt_watchdog ) 
         nmi_watchdog = NMI_LOCAL_APIC;
 
+    sort_exception_tables();
+
     /* Tell the PCI layer not to allocate too close to the RAM area.. */
     low_mem_size = ((max_page << PAGE_SHIFT) + 0xfffff) & ~0xfffff;
     if ( low_mem_size > pci_mem_start ) pci_mem_start = low_mem_size;

xen/include/asm-x86/x86_32/uaccess.h

@@ -85,6 +85,7 @@ struct exception_table_entry
 };
 
 extern unsigned long search_exception_table(unsigned long);
+extern void sort_exception_tables(void);
 
 /**
  * get_user: - Get a simple variable from user space.