Quoting Oren Laadan (orenl@xxxxxxxxxxxxxxx): > 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 | 26 ++++++++++++++++++++++++++ > 1 files changed, 26 insertions(+), 0 deletions(-) > > diff --git a/include/linux/checkpoint.h b/include/linux/checkpoint.h > index 69d14c4..2e99c74 100644 > --- a/include/linux/checkpoint.h > +++ b/include/linux/checkpoint.h > @@ -117,6 +117,32 @@ extern int cr_read_mm(struct cr_ctx *ctx); > extern int cr_read_fd_table(struct cr_ctx *ctx); > extern int cr_read_file(struct cr_ctx *ctx, int objref); > > +/* 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, a, b) \ > + do { \ > + if (op == CR_CPT) \ > + a = b; \ > + else \ > + b = a; \ > + } while (0) > + Speaking from experience with similar sets of macros in capability.h, I'd like to suggest renaming a and b. Something like: #define CR_COPY(op, SAVED, LIVE) \ do { \ if (op == CR_CPT) \ SAVED = LIVE; \ else \ LIVE = SAVED; \ } while (0) That way the next time I need to use CR_COPY, I don't have to agonize over which argument goes where. > +/* > + * Copy @count items from @b to @a if op is CR_CPT (otherwise, > + * copy in the reverse direction) > + */ > +#define CR_COPY_ARRAY(op, a, b, count) \ > + do { \ > + BUILD_BUG_ON(sizeof(*a) != sizeof(*b)); \ > + if (op == CR_CPT) \ > + memcpy(a, b, count * sizeof(*a)); \ > + else \ > + memcpy(b, a, count * sizeof(*a)); \ > + } while (__must_be_array(a) && __must_be_array(b) && 0) > + > + > #define cr_debug(fmt, args...) \ > pr_debug("[%d:c/r:%s] " fmt, task_pid_vnr(current), __func__, ## args) > > -- > 1.5.4.3 _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
