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-rw-r--r--arch/frv/mm/extable.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/frv/mm/extable.c b/arch/frv/mm/extable.c
new file mode 100644
index 000000000000..41be1128dc64
--- /dev/null
+++ b/arch/frv/mm/extable.c
@@ -0,0 +1,91 @@
+/*
+ * linux/arch/frv/mm/extable.c
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <asm/uaccess.h>
+
+extern const struct exception_table_entry __attribute__((aligned(8))) __start___ex_table[];
+extern const struct exception_table_entry __attribute__((aligned(8))) __stop___ex_table[];
+extern const void __memset_end, __memset_user_error_lr, __memset_user_error_handler;
+extern const void __memcpy_end, __memcpy_user_error_lr, __memcpy_user_error_handler;
+extern spinlock_t modlist_lock;
+
+/*****************************************************************************/
+/*
+ *
+ */
+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) {
+ const struct exception_table_entry __attribute__((aligned(8))) *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;
+} /* end search_one_table() */
+
+/*****************************************************************************/
+/*
+ * see if there's a fixup handler available to deal with a kernel fault
+ */
+unsigned long search_exception_table(unsigned long pc)
+{
+ unsigned long ret = 0;
+
+ /* determine if the fault lay during a memcpy_user or a memset_user */
+ if (__frame->lr == (unsigned long) &__memset_user_error_lr &&
+ (unsigned long) &memset <= pc && pc < (unsigned long) &__memset_end
+ ) {
+ /* the fault occurred in a protected memset
+ * - we search for the return address (in LR) instead of the program counter
+ * - it was probably during a clear_user()
+ */
+ return (unsigned long) &__memset_user_error_handler;
+ }
+ else if (__frame->lr == (unsigned long) &__memcpy_user_error_lr &&
+ (unsigned long) &memcpy <= pc && pc < (unsigned long) &__memcpy_end
+ ) {
+ /* the fault occurred in a protected memset
+ * - we search for the return address (in LR) instead of the program counter
+ * - it was probably during a copy_to/from_user()
+ */
+ return (unsigned long) &__memcpy_user_error_handler;
+ }
+
+#ifndef CONFIG_MODULES
+ /* there is only the kernel to search. */
+ ret = search_one_table(__start___ex_table, __stop___ex_table - 1, pc);
+ return ret;
+
+#else
+ /* the kernel is the last "module" -- no need to treat it special */
+ unsigned long flags;
+ struct module *mp;
+
+ spin_lock_irqsave(&modlist_lock, flags);
+
+ for (mp = module_list; mp != NULL; mp = mp->next) {
+ 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, pc);
+ if (ret)
+ break;
+ }
+
+ spin_unlock_irqrestore(&modlist_lock, flags);
+ return ret;
+#endif
+} /* end search_exception_table() */