![]() | |||||||||||||
Messages in this thread |
On Wed, 2006-08-30 at 23:44 +0200, Frank v Waveren wrote: > On Wed, Aug 30, 2006 at 10:44:28AM +0200, Thomas Gleixner wrote: > > Frank v. Waveren pointed out that on 64bit machines the timespec to > > ktime_t conversion might overflow. This is also true for timeval to > > ktime_t conversions. This breaks a "sleep inf" on 64bit machines. > ... > > Check the seconds argument to the conversion and limit it to the maximum > > time which can be represented by ktime_t. > > It's a solution, and it more or less fixes things without any changes > to userspace, which is nice. I still prefer my patch in > <20060827083438.GA6931@var.cx> though, possibly with modifications so > it doesn't affect all timespec users but only nanosleep (we'd have to > check if the other timespec users aren't converting to ktime_t). > > With this patch, we sleep shorter than specified, and don't signal > this in any way. Returning EINVAL for anything except negative tv_sec > or invalid tv_nsec breaks the spec too, but I prefer errors to > silently sleeping too short. I really don't care whether we sleep 100 or 5000 years in the case of "sleep MAX_LONG" > I'll grant this is more of an aesthetic point than something that'll > cause real-world problems (300 years is a long time for any sleep), > but if things break I like them to do so as loudly as possible, as a > general rule. One thing you ignore is that your patch does not cure the introduced user space breakage, it just replaces the overflow caused very short sleep by a return -EINVAL, which is breaking existing userspace in a different way. We have to preserve user space interfaces even when they violate your aesthetic well-being. tglx - 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: 2006-08-30 22:05 [from the cache] ©2003-2008 | |||||||||||||