Unfortunately not :-( root@hitchhiker:/home/alain/cprog# ltrace -S ~alain/bin/x86_64/bindresvport SYS_brk(NULL) = 0x601000 SYS_mmap(0, 4096, 3, 34, 0xffffffff) = 0x7f0d60930000 SYS_access("/etc/ld.so.nohwcap", 00) = -2 SYS_mmap(0, 8192, 3, 34, 0xffffffff) = 0x7f0d6092e000 SYS_access("/etc/ld.so.preload", 04) = -2 SYS_open("/etc/ld.so.cache", 0, 01) = 3 SYS_fstat(3, 0x7fff6892ec20) = 0 SYS_mmap(0, 126618, 1, 2, 3) = 0x7f0d6090f000 SYS_close(3) = 0 SYS_access("/etc/ld.so.nohwcap", 00) = -2 SYS_open("/lib/libc.so.6", 0, 014044600000) = 3 SYS_read(3, "\177ELF\002\001\001", 832) = 832 SYS_fstat(3, 0x7fff6892ec70) = 0 SYS_mmap(0, 0x361278, 5, 2050, 3) = 0x7f0d603b2000 SYS_mprotect(0x7f0d6050a000, 2097152, 0) = 0 SYS_mmap(0x7f0d6070a000, 20480, 3, 2066, 3) = 0x7f0d6070a000 SYS_mmap(0x7f0d6070f000, 17016, 3, 50, 0xffffffff) = 0x7f0d6070f000 SYS_close(3) = 0 SYS_mmap(0, 4096, 3, 34, 0xffffffff) = 0x7f0d6090e000 SYS_mmap(0, 4096, 3, 34, 0xffffffff) = 0x7f0d6090d000 SYS_arch_prctl(4098, 0x7f0d6090d6e0, 0x7f0d6090d6e0, 34, 0) = 0 SYS_mprotect(0x7f0d6070a000, 12288, 1) = 0 SYS_munmap(0x7f0d6090f000, 126618) = 0 __libc_start_main(0x400538, 1, 0x7fff6892f888, 0x4005c0, 0x4005b0 socket(2, 1, 0 SYS_socket(2, 1, 0, 0, 0x7f0d6070f2e0) = 3 <... socket resumed> ) = 3 bindresvport(3, 0, 0, -1, 0x7f0d6070f2e0 SYS_brk(NULL) = 0x601000 SYS_brk(0x622000) = 0x622000 SYS_open("/etc/bindresvport.blacklist", 0, 0666) = 4 SYS_fstat(4, 0x7fff6892f5b0) = 0 SYS_mmap(0, 4096, 3, 34, 0xffffffff) = 0x7f0d6092d000 SYS_read(4, "#\n# This file contains a list of"..., 4096) = 4096 SYS_read(4, "735 # zoz735\n736 # zoz73"..., 4096) = 4096 SYS_read(4, "\n978 # zoz978\n979 # zoz9"..., 4096) = 341 SYS_read(4, "", 4096) = 0 SYS_close(4) = 0 SYS_munmap(0x7f0d6092d000, 4096) = 0 SYS_getpid() = 11756 SYS_bind(3, 0x7fff6892f700, 16, 0, 0xffffffff) = 0 <... bindresvport resumed> ) = 0 SYS_exit_group(0 +++ exited (status 0) +++ So, it really looks like it is only showing the top-level library calls (bindresvport) and syscalls (open, read, write), but not the intermediary library calls (strtoul) Also, further tests showed that even using spaces rather than tabs won't work. In order for the blacklist file to be parsed correctly, it'd need Btw, the bug is marked "Incomplete" right now. What does that mean exactly?