[Valgrind-users] NULL parameters in system calls

[Stephane D. <ste...@ex...>]

Hello,

when using the following system call (which is legal, according to the
accept(2) man page), valgrind 1.9.5 complains about the parameters being
NULL:

  for (;;) {
    fd = accept(server, NULL, NULL);
    if (fd != -1) {
      /* Success. */
      break;
    }



==32217== Syscall param socketcall.accept(addrlen_in) contains
uninitialised or 
unaddressable byte(s)
==32217==    at 0x4073ADE6: __libc_accept (in /lib/i686/libc-2.3.1.so)
==32217==    by 0x401755B9: accept (vg_intercept.c:142)
==32217==    by 0x8049B10: (within /tmp/test)
==32217==    Address 0x0 is not stack'd, malloc'd or free'd
==32217== 
==32217== Syscall param socketcall.accept(addrlen_out) contains
uninitialised or
 unaddressable byte(s)
==32217==    at 0x4073ADE6: __libc_accept (in /lib/i686/libc-2.3.1.so)
==32217==    by 0x401755B9: accept (vg_intercept.c:142)
==32217==    by 0x8049B10: (within /tmp/test)
==32217==    Address 0x0 is not stack'd, malloc'd or free'd



is it possible to patch the syscall wrappers so that they accept legal
NULL values in their parameters ? I tried to find out how to do that,
but I think I need some help to understant the many levels of
indirections in the wrapper invocation.

Thanks in advance

Stephane Donze