commands

gcc -c tc.c -g -ggdb -c
ghc T.hs tc.o -g

stack

(gdb) bt
#0  0x00007fbbf1c0f380 in __read_nocancel () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fbbf1ba6c08 in _IO_new_file_underflow (fp=0x7fbbf1ec64e0 <_IO_2_1_stdin_>) at fileops.c:592
#2  0x00007fbbf1ba7a6e in __GI__IO_default_uflow (fp=0x7fbbf1ec64e0 <_IO_2_1_stdin_>) at genops.c:413
#3  0x00007fbbf1b8aa73 in _IO_vfscanf_internal (s=<optimized out>, format=<optimized out>, argptr=argptr@entry=0x7fff40865458,
    errp=errp@entry=0x0) at vfscanf.c:634
#4  0x00007fbbf1b98a4b in __isoc99_scanf (format=<optimized out>) at isoc99_scanf.c:37
#5  0x0000000000405d4f in another () at tc.c:6
#6  0x000000000040569d in r2nL_info ()

T.hs

{-# LANGUAGE ForeignFunctionInterface #-}

import Foreign
import Foreign.C

foreign import ccall "wrapper" cwrap :: (CInt -> IO CInt) -> IO (FunPtr (CInt -> IO CInt))
foreign import ccall "inside" inside :: FunPtr (CInt -> IO CInt) -> IO ()
foreign import ccall "another" another :: IO ()

waiting :: CInt -> IO CInt
waiting i = print i >> another >> return 27

main = do
  p <- cwrap waiting
  inside p

tc.c

#include <stdio.h>

void another() {
	int i;
	printf("here\n");
	scanf("%i", &i);
}

void other(int (*f)(int)) {
	f(42);
}

void inside(int (*f)(int)) {
	other(f);
}