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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/frv/mm/extable.c
Initial import
Diffstat (limited to 'arch/frv/mm/extable.c')
-rw-r--r--arch/frv/mm/extable.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/frv/mm/extable.c b/arch/frv/mm/extable.c
new file mode 100644
index 000000000..8863d6c1d
--- /dev/null
+++ b/arch/frv/mm/extable.c
@@ -0,0 +1,49 @@
+/*
+ * linux/arch/frv/mm/extable.c
+ */
+
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <asm/uaccess.h>
+
+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;
+
+
+/*****************************************************************************/
+/*
+ * see if there's a fixup handler available to deal with a kernel fault
+ */
+unsigned long search_exception_table(unsigned long pc)
+{
+ const struct exception_table_entry *extab;
+
+ /* 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;
+ }
+
+ 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;
+ }
+
+ extab = search_exception_tables(pc);
+ if (extab)
+ return extab->fixup;
+
+ return 0;
+
+} /* end search_exception_table() */