patch-2.3.43 linux/arch/ia64/mm/extable.c

• Lines: 69
• Date: Sun Feb 6 18:42:40 2000
• Orig file: v2.3.42/linux/arch/ia64/mm/extable.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.42/linux/arch/ia64/mm/extable.c linux/arch/ia64/mm/extable.c
@@ -0,0 +1,68 @@
+/*
+ * Kernel exception handling table support.  Derived from arch/alpha/mm/extable.c.
+ *
+ * Copyright (C) 1998, 1999 Hewlett-Packard Co
+ * Copyright (C) 1998, 1999 David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+
+extern const struct exception_table_entry __start___ex_table[];
+extern const struct exception_table_entry __stop___ex_table[];
+
+static inline const struct exception_table_entry *
+search_one_table (const struct exception_table_entry *first,
+		  const struct exception_table_entry *last,
+		  signed long value)
+{
+	/* Abort early if the search value is out of range.  */
+	if (value != (signed int)value)
+		return 0;
+
+        while (first <= last) {
+		const struct exception_table_entry *mid;
+		long diff;
+		/*
+		 * We know that first and last are both kernel virtual
+		 * pointers (region 7) so first+last will cause an
+		 * overflow.  We fix that by calling __va() on the
+		 * result, which will ensure that the top two bits get
+		 * set again.
+		 */
+		mid = (void *) __va((((__u64) first + (__u64) last)/2/sizeof(*mid))*sizeof(*mid));
+		diff = mid->addr - value;
+                if (diff == 0)
+                        return mid;
+                else if (diff < 0)
+                        first = mid+1;
+                else
+                        last = mid-1;
+        }
+        return 0;
+}
+
+register unsigned long gp __asm__("gp");
+
+const struct exception_table_entry *
+search_exception_table (unsigned long addr)
+{
+#ifndef CONFIG_MODULE
+	/* There is only the kernel to search.  */
+	return search_one_table(__start___ex_table, __stop___ex_table - 1, addr - gp);
+#else
+	struct exception_table_entry *ret;
+	/* The kernel is the last "module" -- no need to treat it special. */
+	struct module *mp;
+
+	for (mp = module_list; mp ; mp = mp->next) {
+		if (!mp->ex_table_start)
+			continue;
+		ret = search_one_table(mp->ex_table_start, mp->ex_table_end - 1, addr - mp->gp);
+		if (ret)
+			return ret;
+	}
+	return 0;
+#endif
+}