BPF crc32 wierd error: last insn is not an exit or jump

Question

Messing around with eBPF and decided to try another crc32 algorithm to try but got stuck with another error that I can't seem to find too much information for. I keep getting a bpf: Failed to load program: Invalid argument last insn is not an exit or jmp. I tried to see if it has anything to do with the way I wrote my functions but all I generate are warnings and then jumping to this error.

bpf_text3 = '''

#include <uapi/linux/ptrace.h>


static int build_crc32_table(void) {
        uint32_t crc=0xFFFFFFFF;
        uint32_t str[256];
for(uint32_t i=0;i<256;i++) {
    uint32_t ch=i;
    for(size_t j=0;j<8;j++) {
        uint32_t b=(ch^crc)&1;
        crc>>=1;
        if(b) crc=crc^0xEDB88320;
        ch>>=1;
    }
    str[i]=crc;
}
return str;
}

int crc32(struct pt_regs *ctx) {
    char str[256];
    strcpy(str, buildcrc32_table());
    //uint32_t str[] = build_crc32_table();
    bpf_probe_read(&str, sizeof(str), (void *)PT_REGS_RC(ctx));

    uint32_t crc=0xFFFFFFFF;
    bpf_trace_printk("BCC - Test Beginning...\\n");
    u64 startTime = bpf_ktime_get_ns();
    for (size_t i = 0; i < sizeof(str); i++) {
        char ch = str[i];
        if (ch == '\\0') break;
        uint32_t t=(ch^crc)&0xFF;
        crc=(crc>>8)^str[t];
        }
    int result = ~crc;
    u64 totalTime = bpf_ktime_get_ns() - startTime;
    bpf_trace_printk(">> BCC - CRC of \\"%s\\" is: 0x%x \\n",str, result);
    bpf_trace_printk(">> BCC - CRC took: %lu cycles\\n", totalTime);
    bpf_trace_printk("BCC - Test Complete.\\n\\n\\n");

    return 0;
    };

'''

Here's also a detailed error that I am seeing:

5 warnings generated. Attaching to uretprobe bpf: Failed to load program: Invalid argument last insn is not an exit or jmp processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0