Re: [patch 7/8] fdmap v2 - implement sys_socket2

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sat, 9 Jun 2007, Al Viro wrote:

> That's simply not true.  On the current kernel nothing stops you from e.g.
> picking a random number and using F_DUPFD.  Voila - there's your randomized
> descriptor.  Portable to earlier kernels.
> 
> Moreover, nonsense^H^H^Hq_fd() can be implemented in userland just fine
> if we allow F_DUPFD to arbitrary number - just pass it a random one *or*
> base chosen like davedel is doing (constant + 20bit random chosen at start
> time).

That does not work. Or better, it works but it forces *huge* fdtables to 
be created. To do that, you need "start" to be over NR_FILE, and this 
creates an fdtable bigger than NR_FILE ((pointer-size + a-few-bits) * 
NR_FILE) propagated down to every app you fork.



- Davide


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux