From: Dan Smith <danms@xxxxxxxxxx>
As suggested by Dave[1], this provides us a way to make the copy-in and
copy-out processes symmetric. CR_COPY_ARRAY() provides us a way to do
the same thing but for arrays. It's not critical, but it helps us unify
the checkpoint and restart paths for some things.
Changelog:
Mar 04:
. Removed semicolons
. Added build-time check for __must_be_array in CR_COPY_ARRAY
Feb 27:
. Changed CR_COPY() to use assignment, eliminating the need
for the CR_COPY_BIT() macro
. Add CR_COPY_ARRAY() macro to help copying register arrays,
etc
. Move the macro definitions inside the CR #ifdef
Feb 25:
. Changed WARN_ON() to BUILD_BUG_ON()
Signed-off-by: Dan Smith <danms@xxxxxxxxxx>
Signed-off-by: Oren Laadan <orenl@xxxxxxxxxxxxxxx>
1: https://lists.linux-foundation.org/pipermail/containers/2009-February/015821.html (all the way at the bottom)
---
include/linux/checkpoint.h | 28 ++++++++++++++++++++++++++++
1 files changed, 28 insertions(+), 0 deletions(-)
diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h
index c83e448..043535c 100644
--- a/include/linux/checkpoint.h
+++ b/include/linux/checkpoint.h
@@ -129,6 +129,34 @@ extern int do_checkpoint(struct cr_ctx *ctx, pid_t pid);
extern int do_restart(struct cr_ctx *ctx, pid_t pid);
+/* useful macros to copy fields and buffers to/from cr_hdr_xxx structures */
+#define CR_CPT 1
+#define CR_RST 2
+
+#define CR_COPY(op, SAVE, LIVE) \
+ do { \
+ if (op == CR_CPT) \
+ SAVE = LIVE; \
+ else \
+ LIVE = SAVE; \
+ } while (0)
+
+/*
+ * Copy @count items from @LIVE to @SAVE if op is CR_CPT (otherwise,
+ * copy in the reverse direction)
+ */
+#define CR_COPY_ARRAY(op, SAVE, LIVE, count) \
+ do { \
+ (void)__must_be_array(SAVE); \
+ (void)__must_be_array(LIVE); \
+ BUILD_BUG_ON(sizeof(*SAVE) != sizeof(*LIVE)); \
+ if (op == CR_CPT) \
+ memcpy(SAVE, LIVE, count * sizeof(*SAVE)); \
+ else \
+ memcpy(LIVE, SAVE, count * sizeof(*SAVE)); \
+ } while (0)
+
+
#define cr_debug(fmt, args...) \
pr_debug("[%d:c/r:%s] " fmt, task_pid_vnr(current), __func__, ## args)
--
1.5.4.3
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