=== Running test binary ===
sh: line 1: /dev/shm/min2: Permission denied
Exit: 126

=== Now build full exploit ===
Written: 4720 bytes

=== Compiling ===
min3.c: In function '_start':
min3.c:135:9: warning: implicit declaration of function 'sys4'; did you mean 'sys0'? [-Wimplicit-function-declaration]
  135 |         sys4(61, pid, 0, 0, 0); // wait4
      |         ^~~~
      |         sys0
/bin/ld: /tmp/cccwq7Mz.o: in function `_start':
min3.c:(.text+0x841): undefined reference to `sys4'
collect2: error: ld returned 1 exit status
Compile exit: 1

=== DONE ===