yingc@yingc:~/gcyin/test/thirdparty/ffmpeg/FFmpeg-master$ perl -e 'print "A"x257'

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAyingc@yingc:~/gcyin/test/thirdparty/ffmpeg/FFmpeg-master$ 

(gdb) disassemble func

Dump of assembler code for function func:

   0x08048464 <+0>:    push   %ebp

   0x08048465 <+1>:    mov    %esp,%ebp

   0x08048467 <+3>:    sub    $0x128,%esp

   0x0804846d <+9>:    mov    0x8(%ebp),%eax

   0x08048470 <+12>:    mov    %eax,-0x11c(%ebp)

   0x08048476 <+18>:    mov    %gs:0x14,%eax

   0x0804847c <+24>:    mov    %eax,-0xc(%ebp)

   0x0804847f <+27>:    xor    %eax,%eax

   0x08048481 <+29>:    movl   $0x0,-0x110(%ebp)

   0x0804848b <+39>:    jmp    0x80484b1 <func+77>

   0x0804848d <+41>:    mov    -0x110(%ebp),%eax

   0x08048493 <+47>:    add    -0x11c(%ebp),%eax

   0x08048499 <+53>:    movzbl (%eax),%edx

   0x0804849c <+56>:    lea    -0x10c(%ebp),%eax

   0x080484a2 <+62>:    add    -0x110(%ebp),%eax

   0x080484a8 <+68>:    mov    %dl,(%eax)

   0x080484aa <+70>:    addl   $0x1,-0x110(%ebp)

   0x080484b1 <+77>:    cmpl   $0x100,-0x110(%ebp)

   0x080484bb <+87>:    jle    0x804848d <func+41>

   0x080484bd <+89>:    mov    -0xc(%ebp),%edx

   0x080484c0 <+92>:    xor    %gs:0x14,%edx

   0x080484c7 <+99>:    je     0x80484ce <func+106>

   0x080484c9 <+101>:    call   0x8048360 <__stack_chk_fail@plt>

   0x080484ce <+106>:    leave

   0x080484cf <+107>:    ret

End of assembler dump.

(gdb) b *0x80484ce

Breakpoint 1 at 0x80484ce: file suid.c, line 27.

(gdb) set args `perl -e 'print "A"x257'`