new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those
note that they are relying on access_ok() already checked by caller.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/compat.h b/include/linux/compat.h
index cb5637e..3348133 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -647,6 +647,7 @@
compat_stack_t __user *uoss_ptr);
int compat_restore_altstack(const compat_stack_t __user *uss);
+int __compat_save_altstack(compat_stack_t __user *, unsigned long);
#endif
#else