[PATCH] Linux: Add fortify wrapper for getdents64

[Florian Weimer]

* Adhemerval Zanella:

>> +ssize_t
>> +__getdents64_chk (int fd, void *dst, size_t len, size_t dstlen)
>> +{
>> +  if (__glibc_unlikely (dstlen < len))
>> +    __chk_fail ();
>> +  return __getdents64 (fd, dst, len);
>> +}
>
> __chk_fail is exported in libc ABI, wouldn't be better to just inline it
> and avoid a new symbol?

None of the existing wrappers do this.  The advantage of not inling is
that you can look at a coredump and see __getdents64_chk in libc.so.6 in
the stack trace, even with (application) debugging symbols available.

Thanks,
Florian