waterInvestigationHiddenDanger rtuDataOperation.h 李海忠 commit at 2020-10-13

waterInvestigationHiddenDanger/databaseOperation/rtuDataOperation.h

@@ -0,0 +1,47 @@
+#ifndef _ASM_IA64_UACCESS_H
+#define _ASM_IA64_UACCESS_H
+
+/*
+ * This file defines various macros to transfer memory areas across
+ * the user/kernel boundary.  This needs to be done carefully because
+ * this code is executed in kernel mode and uses user-specified
+ * addresses.  Thus, we need to be careful not to let the user to
+ * trick us into accessing kernel memory that would normally be
+ * inaccessible.  This code is also fairly performance sensitive,
+ * so we want to spend as little time doing safety checks as
+ * possible.
+ *
+ * To make matters a bit more interesting, these macros sometimes also
+ * called from within the kernel itself, in which case the address
+ * validity check must be skipped.  The get_fs() macro tells us what
+ * to do: if get_fs()==USER_DS, checking is performed, if
+ * get_fs()==KERNEL_DS, checking is bypassed.
+ *
+ * Note that even if the memory area specified by the user is in a
+ * valid address range, it is still possible that we'll get a page
+ * fault while accessing it.  This is handled by filling out an
+ * exception handler fixup entry for each instruction that has the
+ * potential to fault.  When such a fault occurs, the page fault
+ * handler checks to see whether the faulting instruction has a fixup
+ * associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and
+ * then resumes execution at the continuation point.
+ *
+ * Based on <asm-alpha/uaccess.h>.
+ *
+ * Copyright (C) 1998, 1999, 2001-2004 Hewlett-Packard Co
+ *	David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/page-flags.h>
+#include <linux/mm.h>
+
+#include <asm/intrinsics.h>
+#include <asm/pgtable.h>
+#include <asm/io.h>
+
+/*
+ * For historical reasons, the following macros are grossly misnamed:
+ */