criu C API dump does not work

[nakasan617]

I am trying to dump the program state using criu C API, however it seems that there's multiple errors that doesn't really allow me to check point. My sample code for a tracee is below

#include <stdio.h>
#include <unistd.h>

int main()
{
    //for(int i = 0; i < 20; i++)
    for(int i = 0;;i++)
    {   
        printf("HELLO %d\n", i); 
        sleep(1);

    }   
}

The code to get the checkpoint is below

#define _POSIX_C_SOURCE 200809L

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <assert.h>
#include "path/to/criu.h"

int main(int argc, char **argv)
{
    assert(argc == 2); 

    int fd = open("tmp/dump", O_DIRECTORY);
    if(fd == -1) 
    {   
        fprintf(stderr, "failed to open: %s\n", strerror(errno));
        return 1;
    }   

    int pid = atoi(argv[1]); 
    criu_init_opts();
    criu_set_service_address(NULL);
    criu_set_pid(pid);
    //criu_set_service_binary("./sample");
    criu_set_images_dir_fd(fd);
    criu_set_log_level(4);
    //criu_set_log_file("dump.log");
    int rv = criu_dump();

    printf("criu_dump returned %d\n", rv);
    return 0;  
}

I run them in the following step.

1. compile with libcriu.so linked for the checkpointing code
2. run the sample code
3. check the pid with ps -ef | grep sample
4. run the checkpointing code in root (e.g. if the pid of the sample was 10000, sudo ./a.out 10000)

Describe the results you received: I get the following outputs.

Can't exec criu swrk: No such file or directory
Can't read request: Connection reset by peer
Can't receive response: Connection reset by peer
criu_dump returned -70

I can make the first error message go away by simply uncommenting the line with function //criu_set_service_binary("./sample"); but it would start the sample process from the beginning with execlp, and that's not what I want. Has anyone faced the similar/same issue?

Additional information you deem important (e.g. issue happens only occasionally): I ran on ubuntu 16.04. I am using the following version on git repo: commit 98ac646f868d97b621c81939a8139e7a63d37393

[adrianreber]

libcriu needs the criu binary in the path and it sounds like it cannot find the criu binary.

[rst0git]

Can't exec criu swrk: No such file or directory

The criu_set_service_binary() function can also be used to set the path to the criu binary.

Example:

https://github.com/checkpoint-restore/criu/blob/8cf99be39709238a99aaf5ca9f7f83f04233b3f4/test/others/libcriu/test_join_ns.c#L72

[nakasan617]

thank you. I was making the binary to be the tracee. So that was a dumb mistake...