[Samba] samba 4.12 build on hp-ux unsupported system calls

[Jeremy Allison]

On Wed, Apr 08, 2020 at 09:58:26AM +0000, Kumar, Arjit (SSTO) via samba wrote:
> Hi Team,
> 
> We are having compile/linking time warning due unsatisfied system calls and macros.
> We have checked and confirm that these are not supported by hp-ux kernel and enabling them will require changes in VFS layer and physical filesystem.
> 
> Unsatisfied system calls
> 
> *        renameat
> 
> *        symlinkat
> 
> *        linkat
> 
> *        unlinkat
> 
> *        readlinkat
> 
> *        mkdirat
> 
> Undefined MACRO's
> 
> *        AT_REMOVEDIR
> 
> *        AT_FDCWD
> 
> These system calls have been added newly in samba 4.12.
> 
> Please provide workaround/patch to use older syscalls like mkdir,readlink,unlink etc within samba 4.12.

I'm afraid that can't be done.

It's not possible to write a secure path-safe
modern application without the XXXXat() calls.

That's why we're moving to require them.

HPUX kernel will have to add these calls,
or the HPUX ecosystem can't be maintained
going forward. Sorry for the bad news :-(.

Either that or you'll have to add mappings
in your libc to emulate these calls, but
that won't be secure I'm afraid.