tested the patched glibc-2.15 as well as the latest git mainline

$ cat test.c
#include <stdio.h>
#include <string.h>
int main() {
    char line[] = "udf 75868 1 - Live 0xffffffffa0bfb000\n";
    char *saveptr, *tok = strtok_r(line, " \t", &saveptr);
    printf("tok: {%s}\nshould be: {udf}\n", tok);
    return 0;
}

$ gcc -Wall test.c -m64 && ./a.out
tok: {udf}
should be: {udf}

$ gcc -Wall test.c -m32 && ./a.out
tok: {udf}
should be: {udf}

$ gcc -Wall test.c -mx32 && ./a.out
tok: {}
should be: {udf}