On Wed, Jul 23, 2014, at 13:52, George Spelvin wrote: > I keep wishing for a more general solution. For example, some way to > have a "spare" extra fd that could be accessed with a special O_NOFAIL > flag. > > That would allow any number of library functions to not fail, such as > logging from nasty corner cases. > > But you'd have to provide one per thread, and block non-fatal signals > while it was open, so you don't get reentrancy problems. Ick. > > > This overly-specialized system call (and worse yet, a blocking > system call that you can't put into a poll() loop) just feels ugly > to me. Is it *absolutely* necessary? One point that often came up besides fd exhaustion is missing /dev/u?random device nodes in chroot environments. I also thought about a more general interface, like e.g. an opennod(dev_t device, int flags) call but all those ideas ended up being very complex changes besides having design issues. getrandom is simple and solves a real problem. The only problem I see, that we allow access to /dev/random without checking any permission bits like we did on opening /dev/random before and we cannot restrict applications to deplete the whole entropy pool. > For example, how about simply making getentropy() a library function that > aborts if it can't open /dev/urandom? If you're suffering fd exhaustion, > you're being DoSed already. Maybe applications want to mitigate fd exhaustion. Bye, Hannes -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
