On Sat, 13 Nov 2010 14:38:19 -0700 Andreas Dilger <adilger.kernel@xxxxxxxxx> wrote: > On 2010-11-12, at 13:08, Andrew Morton wrote: > > On Wed, 10 Nov 2010 23:38:02 +0300 > > Vasiliy Kulikov <segooon@xxxxxxxxx> wrote: > >> On some architectures __kernel_suseconds_t is int. > > > > On sparc and parisc. On all other architectures this patch is a waste > > of cycles. > > > > --- a/fs/select.c~fs-select-fix-information-leak-to-userspace-fix > > +++ a/fs/select.c > > @@ -306,7 +306,8 @@ static int poll_select_copy_remaining(st > > rts.tv_sec = rts.tv_nsec = 0; > > > > if (timeval) { > > - memset(&rtv, 0, sizeof(rtv)); > > + if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec)) > > + memset(&rtv, 0, sizeof(rtv)); > > rtv.tv_sec = rts.tv_sec; > > rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; > > > > _ > > > > > > The `if' gets eliminated at compile time. With this approach we add > > four bytes of text to the sparc64 build and zero bytes of text to the > > x86_64 build. > > It's nice to have comments (or at least a good commit message) for unusual code like this, so that in the future it is clear when this kind of workaround can be removed (e.g. if the time_t is changed to always be a 64-bit value for Y2038 issues, even on 32-bit arches). > Well, I'm the resident comment fanatic, but I thought this was all sufficiently obvious to not need one. But I'll add one ;) -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html