I Can't transfert data from PL to PS

Hello,

I Can't transfert data from PL to PS.

I set mem=800M in my devicetree.dts

Cotu00E9 PL :
I write data DDR3 adress:0xc8000000 size 0X40

*******PS*******
On Ubuntu Linaro, I excecute following code :

#define FILEPATH "/dev/mem"
#define NUMINTS (448)
#define FILESIZE (NUMINTS * sizeof(char))
#define BASEADDRESS (0xc8000000)

    fd = open(FILEPATH, O_RDWR | O_SYNC);
    if (fd == -1) {
       perror("Error opening file for reading");
       exit(EXIT_FAILURE);
    }

    map = mmap(NULL, FILESIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, (off_t) BASEADDRESS);
    if (map == MAP_FAILED) {
       perror("Error mmapping the file");
       exit(EXIT_FAILURE);
    }

    printf("init_read_mmap OK!
");

    return map;

I don't reach to transfert data from PL to PS
I have the folowing messsage :
Unhandled fault: external abort on non-linefetch (0x018) at 0xb6fa4000

Thank in advance for your help