checkpoint/restore support for bpf-map fd

[rst0git]

We need to add support for checkpoint/restore of bpf-map file descriptors.

This is a simple example of how to open such file descriptor:

#include <stdio.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <sys/syscall.h>

static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
			  unsigned int size)
{
	return syscall(__NR_bpf, cmd, attr, size);
}

int bpf_create_map(enum bpf_map_type map_type,
		   unsigned int key_size,
		   unsigned int value_size,
		   unsigned int max_entries)
{
	union bpf_attr attr = {
	  .map_type    = map_type,
	  .key_size    = key_size,
	  .value_size  = value_size,
	  .max_entries = max_entries
	};

	return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
}

int main()
{
	int fd = bpf_create_map(BPF_MAP_TYPE_PROG_ARRAY, sizeof(int), sizeof(int), 4);
	printf("bpf-map fd: %d\n", fd);
	getchar();
	return 0;
}

When trying to checkpoint this process CRIU fails with:

Error (criu/files-ext.c:95): Can't dump file 3 of that type [600] (anon anon_inode:bpf-map)
...
Error (criu/cr-dump.c:1754): Dumping FAILED.