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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/sh/mm/extable_64.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/sh/mm/extable_64.c')
-rw-r--r--kernel/arch/sh/mm/extable_64.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/kernel/arch/sh/mm/extable_64.c b/kernel/arch/sh/mm/extable_64.c
new file mode 100644
index 000000000..f05499688
--- /dev/null
+++ b/kernel/arch/sh/mm/extable_64.c
@@ -0,0 +1,82 @@
+/*
+ * arch/sh/mm/extable_64.c
+ *
+ * Copyright (C) 2003 Richard Curnow
+ * Copyright (C) 2003, 2004 Paul Mundt
+ *
+ * Cloned from the 2.5 SH version..
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/rwsem.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+
+extern unsigned long copy_user_memcpy, copy_user_memcpy_end;
+extern void __copy_user_fixup(void);
+
+static const struct exception_table_entry __copy_user_fixup_ex = {
+ .fixup = (unsigned long)&__copy_user_fixup,
+};
+
+/*
+ * Some functions that may trap due to a bad user-mode address have too
+ * many loads and stores in them to make it at all practical to label
+ * each one and put them all in the main exception table.
+ *
+ * In particular, the fast memcpy routine is like this. It's fix-up is
+ * just to fall back to a slow byte-at-a-time copy, which is handled the
+ * conventional way. So it's functionally OK to just handle any trap
+ * occurring in the fast memcpy with that fixup.
+ */
+static const struct exception_table_entry *check_exception_ranges(unsigned long addr)
+{
+ if ((addr >= (unsigned long)&copy_user_memcpy) &&
+ (addr <= (unsigned long)&copy_user_memcpy_end))
+ return &__copy_user_fixup_ex;
+
+ return NULL;
+}
+
+/* Simple binary search */
+const struct exception_table_entry *
+search_extable(const struct exception_table_entry *first,
+ const struct exception_table_entry *last,
+ unsigned long value)
+{
+ const struct exception_table_entry *mid;
+
+ mid = check_exception_ranges(value);
+ if (mid)
+ return mid;
+
+ while (first <= last) {
+ long diff;
+
+ mid = (last - first) / 2 + first;
+ diff = mid->insn - value;
+ if (diff == 0)
+ return mid;
+ else if (diff < 0)
+ first = mid+1;
+ else
+ last = mid-1;
+ }
+
+ return NULL;
+}
+
+int fixup_exception(struct pt_regs *regs)
+{
+ const struct exception_table_entry *fixup;
+
+ fixup = search_exception_tables(regs->pc);
+ if (fixup) {
+ regs->pc = fixup->fixup;
+ return 1;
+ }
+
+ return 0;
+}