> On Thu, 8 Nov 2007 12:53:57 +1100 Paul Mackerras <[EMAIL PROTECTED]> wrote: > Andrew Morton writes: > > > Given all this stuff, the return value from sys_times() doesn't seem a > > particularly useful or reliable kernel interface. > > I think the best thing would be to ignore any error from copy_to_user > and always return the number of clock ticks. We should call > force_successful_syscall_return, and glibc on x86 should be taught not > to interpret negative values as an error.
Changing glibc might be hard ;) > POSIX doesn't require us to return an EFAULT error if the buf argument > is bogus. If userspace does supply a bogus buf pointer, then either > it will dereference it itself and get a segfault, or it won't > dereference it, in which case it obviously didn't care about the > values we tried to put there. > > If we try to return an error under some circumstances, then there is > at least one 32-bit value for the number of ticks that will cause > confusion. We can either change that value (or values) to some other > value, which seems pretty bogus, or we can just decide not to return > any errors. The latter seems to me to have no significant downside > and to be the simplest solution to the problem. "the latter" is what my protopatch does isn't it? It wraps at 0x7fffffff. It appears that glibc treats all of 0x80000000-0xffffffff as an error. - 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/
