[CRIU] [PATCH 03/38] compel: Add arguments packing helper

[Cyrill Gorcunov]

Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
---
 compel/Makefile              |  2 ++
 compel/include/uapi/compel.h |  4 ++++
 compel/src/lib/argv.c        | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+)
 create mode 100644 compel/src/lib/argv.c

diff --git a/compel/Makefile b/compel/Makefile
index bfb79237dbb2..eb46393f3355 100644
--- a/compel/Makefile
+++ b/compel/Makefile
@@ -15,6 +15,8 @@ host-lib-y		+= arch/$(ARCH)/src/lib/handle-elf.o
 lib-y			+= src/lib/handle-elf.o
 host-lib-y		+= src/lib/handle-elf.o
 
+lib-y			+= src/lib/argv.o
+
 ifeq ($(ARCH),x86)
 lib-y			+= src/lib/handle-elf-32.o
 host-lib-y		+= src/lib/handle-elf-32.o
diff --git a/compel/include/uapi/compel.h b/compel/include/uapi/compel.h
index 10507ce3fb22..9148f94bda45 100644
--- a/compel/include/uapi/compel.h
+++ b/compel/include/uapi/compel.h
@@ -14,4 +14,8 @@ typedef struct {
 	long		value;
 } compel_reloc_t;
 
+extern int libcompel_pack_argv(void *blob, size_t blob_size,
+			       int argc, char **argv,
+			       void **arg_p, size_t *arg_size);
+
 #endif /* UAPI_COMPEL_H__ */
diff --git a/compel/src/lib/argv.c b/compel/src/lib/argv.c
new file mode 100644
index 000000000000..86f354e83679
--- /dev/null
+++ b/compel/src/lib/argv.c
@@ -0,0 +1,39 @@
+#include <stdlib.h>
+#include <string.h>
+
+#include "uapi/compel.h"
+
+int libcompel_pack_argv(void *blob, size_t blob_size,
+			int argc, char **argv,
+			void **arg_p, size_t *arg_size)
+{
+	unsigned long *argv_packed;
+	size_t total_len;
+	int i, *argc_packed;
+	char *args_mem;
+
+	total_len = sizeof(int);
+	total_len += sizeof(unsigned long) + blob_size + 1;
+	for (i = 0; i < argc; i++)
+		total_len += sizeof(unsigned long) + strlen(argv[i]) + 1;
+
+	argc_packed = malloc(total_len);
+	if (!argc_packed)
+		return -ENOMEM;
+
+	*argc_packed = argc + 1;
+	argv_packed = (unsigned long *)(argc_packed + 1);
+	args_mem = (char *)(argv_packed + argc + 1);
+	argv_packed[0] = (void *)args_mem - (void *)argc_packed;
+	memcpy(args_mem, blob, blob_size);
+	args_mem += blob_size + 1;
+	for (i = 0; i < argc; i++) {
+		argv_packed[i + 1] = (void *)args_mem - (void *)argc_packed;
+		args_mem = stpcpy(args_mem, argv[i]) + 1;
+	}
+
+	*arg_p = argc_packed;
+	*arg_size = total_len;
+
+	return 0;
+}
-- 
2.7.4