execve syscall returning EFAULT using 32bit call conventions on 64bit AMD
.global main
main:
    jmp     two

one:
    # zero rax and rdx
    xor     %rax,%rax
    mov     %rax,%rdx

    # save string location
    mov     (%rsp),%rbx

    # push argv array onto the stack
    add     $16, %rsp
    push    %rax
    push    %rbx
    # assign argv pointer
    mov     %rsp,%rcx

    # execve call
    mov     $0xb, %al
    int     $0x80

    # exit on failure
    xor     %rax,%rax
    xor     %rbx,%rbx
    movb    $0x1,%al
    int     $0x80

two:
    # get address of the string
    call    one
    .string "/bin/date"

(gdb) info registers
rax            0xb  11
rbx            0x4000a0 4194464
rcx            0x7fffffffe968   140737488349544
rdx            0x0  0

(gdb) x/s $rbx
0x4000a0:    "/bin/date"

(gdb) x/s *$rcx
0x4000a0:    "/bin/date"

.global main
main:
    jmp     two

one:
    # zero rax and rdx
    xor     %rax,%rax
    mov     %rax,%rdx

    # save string location, note that %rdi is used instead of %rbx
    pop     %rdi

    # push argv array onto the stack
    add     $16, %rsp
    push    %rax
    push    %rdi
    # assign argv pointer, using %rsi instead of %rcx
    mov     %rsp,%rsi

    # execve call, note that the syscall number is different than in 32bit
    mov     $0x3b, %al
    syscall

two:
    # get address of the string
    call    one
    .string "/bin/date"

int execve(const char *filename,
           char *const argv[],
           char *const envp[]);

char *filename = "/bin/date";
char *argv [2] = {filename, NULL};
char *envp [1] = {NULL};

execve (filename, argv, envp);

char *filename = "/bin/date";

execve (filename, NULL);   // note missing third parameter, and malformed argv[]