patch-2.4.21 linux-2.4.21/arch/ppc64/mm/extable.c

• Lines: 120
• Date: 2003-06-13 07:51:32.000000000 -0700
• Orig file: linux-2.4.20/arch/ppc64/mm/extable.c
• Orig date: 2002-08-02 17:39:43.000000000 -0700

diff -urN linux-2.4.20/arch/ppc64/mm/extable.c linux-2.4.21/arch/ppc64/mm/extable.c
@@ -1,5 +1,5 @@
 /*
- * linux/arch/ppc/mm/extable.c
+ * linux/arch/ppc64/mm/extable.c
  *
  * from linux/arch/i386/mm/extable.c
  *
@@ -9,54 +9,95 @@
  *      2 of the License, or (at your option) any later version.
  */
 
+#include <linux/config.h>
 #include <linux/module.h>
+#include <linux/spinlock.h>
 #include <asm/uaccess.h>
 
-extern const struct exception_table_entry __start___ex_table[];
-extern const struct exception_table_entry __stop___ex_table[];
+extern struct exception_table_entry __start___ex_table[];
+extern struct exception_table_entry __stop___ex_table[];
+
+/*
+ * The exception table needs to be sorted because we use the macros
+ * which put things into the exception table in a variety of segments
+ * as well as the init segment and the main kernel text segment.
+ */
+static inline void
+sort_ex_table(struct exception_table_entry *start,
+	      struct exception_table_entry *finish)
+{
+	struct exception_table_entry el, *p, *q;
+
+	/* insertion sort */
+	for (p = start + 1; p < finish; ++p) {
+		/* start .. p-1 is sorted */
+		if (p[0].insn < p[-1].insn) {
+			/* move element p down to its right place */
+			el = *p;
+			q = p;
+			do {
+				/* el comes before q[-1], move q[-1] up one */
+				q[0] = q[-1];
+				--q;
+			} while (q > start && el.insn < q[-1].insn);
+			*q = el;
+		}
+	}
+}
+
+void
+sort_exception_table(void)
+{
+	sort_ex_table(__start___ex_table, __stop___ex_table);
+}
 
 static inline unsigned long
 search_one_table(const struct exception_table_entry *first,
 		 const struct exception_table_entry *last,
 		 unsigned long value)
 {
-        while (first <= last) {
+	while (first <= last) {
 		const struct exception_table_entry *mid;
 		long diff;
 
 		mid = (last - first) / 2 + first;
 		diff = mid->insn - value;
-                if (diff == 0)
-                        return mid->fixup;
-                else if (diff < 0)
-                        first = mid+1;
-                else
-                        last = mid-1;
-        }
-        return 0;
+		if (diff == 0)
+			return mid->fixup;
+		else if (diff < 0)
+			first = mid+1;
+		else
+			last = mid-1;
+	}
+	return 0;
 }
 
+extern spinlock_t modlist_lock;
+
 unsigned long
 search_exception_table(unsigned long addr)
 {
-	unsigned long ret;
+	unsigned long ret = 0;
 
 #ifndef CONFIG_MODULES
 	/* There is only the kernel to search.  */
 	ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
-	if (ret) return ret;
+	return ret;
 #else
+	unsigned long flags;
 	/* The kernel is the last "module" -- no need to treat it special.  */
 	struct module *mp;
+
+	spin_lock_irqsave(&modlist_lock, flags);
 	for (mp = module_list; mp != NULL; mp = mp->next) {
-		if (mp->ex_table_start == NULL)
+		if (mp->ex_table_start == NULL || !(mp->flags&(MOD_RUNNING|MOD_INITIALIZING)))
 			continue;
 		ret = search_one_table(mp->ex_table_start,
 				       mp->ex_table_end - 1, addr);
 		if (ret)
-			return ret;
+			break;
 	}
+	spin_unlock_irqrestore(&modlist_lock, flags);
+	return ret;
 #endif
-
-	return 0;
 }