[CRIU] [PATCH 4/5] compel: Remove size/bsize from blob desc

[Pavel Emelyanov]

The size value should be page_size() aligned, which is
inconvenient for callers, and also differs from the bsize
only a little bit, so it's nicer to have the nr_gotpcrel
value which is anyway generated by compel hgen.

Signed-off-by: Pavel Emelyanov <xemul at virtuozzo.com>
---
 compel/include/uapi/infect.h |  4 ++--
 compel/src/lib/infect.c      | 11 ++++++++---
 criu/parasite-syscall.c      |  2 +-
 criu/pie/pie-relocs.h        |  2 ++
 4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/compel/include/uapi/infect.h b/compel/include/uapi/infect.h
index 746026c..142bef6 100644
--- a/compel/include/uapi/infect.h
+++ b/compel/include/uapi/infect.h
@@ -139,8 +139,8 @@ struct parasite_blob_desc {
 	union {
 		struct {
 			const void		*mem;
-			size_t			bsize; /* size of the blob */
-			size_t			size;  /* size of the blob with relocs */
+			size_t			bsize;
+			size_t			nr_gotpcrel;
 			unsigned long		parasite_ip_off;
 			unsigned long		addr_cmd_off;
 			unsigned long		addr_arg_off;
diff --git a/compel/src/lib/infect.c b/compel/src/lib/infect.c
index f726c47..db1aa25 100644
--- a/compel/src/lib/infect.c
+++ b/compel/src/lib/infect.c
@@ -840,10 +840,15 @@ int compel_map_exchange(struct parasite_ctl *ctl, unsigned long size)
 	return ret;
 }
 
+static inline unsigned long total_pie_size(size_t blob_size, size_t nr_gp)
+{
+	return round_up(blob_size + nr_gp * sizeof(long), page_size());
+}
+
 int compel_infect(struct parasite_ctl *ctl, unsigned long nr_threads, unsigned long args_size)
 {
 	int ret;
-	unsigned long p, map_exchange_size, parasite_size = 0;
+	unsigned long p, map_exchange_size, pie_size, parasite_size = 0;
 
 	if (ctl->pblob.parasite_type != COMPEL_BLOB_CHEADER)
 		goto err;
@@ -861,7 +866,7 @@ int compel_infect(struct parasite_ctl *ctl, unsigned long nr_threads, unsigned l
 	 * without using ptrace at all.
 	 */
 
-	parasite_size = ctl->pblob.hdr.size;
+	pie_size = parasite_size = total_pie_size(ctl->pblob.hdr.bsize, ctl->pblob.hdr.nr_gotpcrel);
 
 	ctl->args_size = round_up(args_size, PAGE_SIZE);
 	parasite_size += ctl->args_size;
@@ -881,7 +886,7 @@ int compel_infect(struct parasite_ctl *ctl, unsigned long nr_threads, unsigned l
 	ctl->addr_cmd = ctl->local_map + ctl->pblob.hdr.addr_cmd_off;
 	ctl->addr_args = ctl->local_map + ctl->pblob.hdr.addr_arg_off;
 
-	memcpy(ctl->local_map, ctl->pblob.hdr.mem, ctl->pblob.hdr.size);
+	memcpy(ctl->local_map, ctl->pblob.hdr.mem, pie_size);
 	if (ctl->pblob.hdr.nr_relocs)
 		compel_relocs_apply(ctl->local_map, ctl->remote_map, ctl->pblob.hdr.bsize,
 				    ctl->pblob.hdr.relocs, ctl->pblob.hdr.nr_relocs);
diff --git a/criu/parasite-syscall.c b/criu/parasite-syscall.c
index ac33fbf..d817000 100644
--- a/criu/parasite-syscall.c
+++ b/criu/parasite-syscall.c
@@ -547,9 +547,9 @@ static int make_sigframe(void *arg, struct rt_sigframe *sf, struct rt_sigframe *
 #endif
 
 #define init_blob_desc(bdesc, blob_type) do {						\
-	bdesc->hdr.size = pie_size(parasite_##blob_type);				\
 	bdesc->hdr.mem = parasite_##blob_type##_blob;					\
 	bdesc->hdr.bsize = sizeof(parasite_##blob_type##_blob);				\
+	bdesc->hdr.nr_gotpcrel = pie_nr_gotpcrel(parasite_##blob_type);			\
 	/* Setup the rest of a control block */						\
 	bdesc->hdr.parasite_ip_off = pblob_offset(blob_type, __export_parasite_head_start);\
 	bdesc->hdr.addr_cmd_off    = pblob_offset(blob_type, __export_parasite_cmd);	\
diff --git a/criu/pie/pie-relocs.h b/criu/pie/pie-relocs.h
index 442e70d..a96150a 100644
--- a/criu/pie/pie-relocs.h
+++ b/criu/pie/pie-relocs.h
@@ -10,6 +10,7 @@
 
 #define pie_size(__pie_name)	(round_up(sizeof(__pie_name##_blob) + \
 			__pie_name ## _nr_gotpcrel * sizeof(long), page_size()))
+#define pie_nr_gotpcrel(__pie_name)	(__pie_name ## _nr_gotpcrel)
 #define ELF_RELOCS_APPLY(__pie_name, __mem, __vbase)			\
 	compel_relocs_apply(__mem, __vbase, sizeof(__pie_name##_blob),	\
 			 __pie_name##_relocs, ARRAY_SIZE(__pie_name##_relocs))
@@ -17,6 +18,7 @@
 #else
 
 #define pie_size(__pie_name)	(round_up(sizeof(__pie_name##_blob), page_size()))
+#define pie_nr_gotpcrel(__pie_name)	(0)
 #define ELF_RELOCS_APPLY(__pie_name, __mem, __vbase)
 
 #endif
-- 
2.5.0