![]() | |||||||||||||
Messages in this thread |
On Sun, 3 Jun 2007, Ulrich Drepper wrote: > -----BEGIN PGP SIGNED MESSAGE-----> Hash: SHA1> > Davide Libenzi wrote:> >> I agree with Ingo, no need for a second magic value. Use the same value > >> as FD_UNSEQ_ALLOC which will just mean this exact value should never be > >> used as a file descriptor.> > > > I explained this in my answer to Ingo...> > And if we have a new syscall we don't need any of that special dup2 > behavior you describe. I really don't think this should be added. dup2 > should just do what POSIX specifies, nothing more. I would even suggest > to not allow to dup2() to a descriptor > RLIMIT_NOFILE unless it is > already allocated. I.e., don't allow creating arbitrary high descriptors. > > This behavior is completely consistent with the current implementation. > No bad surprises. In fact, it eliminates parts of the ABI > incompatibility I talked about. Agreed, a new syscall looks less messy. I'll make sys_dup2() to allow installing in the non-sequential area, only if there's an fd already allocated. F_DUPFD will remain unchanged (that is, not allow non-sequential fds allocations). > > Random can be expensive. At the moment is FIFO. I'm missing though how > > this can be a security flaw, when the legacy one is exactly predictable.> > It's not an added security issue. It would mean removing a possible > security the current file descriptor allocation has. > > If randomizing each allocator is too expensive then randomize at the > very least the number of the first descriptor you give out. Can you tell me how this can be a problem, and in which way making a random thing would help? - Davide - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2007-06-03 20:23 [from the cache] ©2003-2008 | |||||||||||||