On Mon, Feb 9, 2009 at 11:06 AM, Davide Libenzi <davidel@xxxxxxxxxxxxxxx> wrote: > On Mon, 9 Feb 2009, Michael Kerrisk wrote: > >> On Mon, Feb 9, 2009 at 10:50 AM, Davide Libenzi <davidel@xxxxxxxxxxxxxxx> wrote: >> > On Mon, 9 Feb 2009, Michael Kerrisk wrote: >> > >> >> > @@ -186,12 +187,9 @@ SYSCALL_DEFINE2(timerfd_create, int, clo >> >> > BUILD_BUG_ON(TFD_CLOEXEC != O_CLOEXEC); >> >> > BUILD_BUG_ON(TFD_NONBLOCK != O_NONBLOCK); >> >> > >> >> > - if (flags & ~(TFD_CLOEXEC | TFD_NONBLOCK)) >> >> > + if ((flags & ~TFD_FLAGS_SET) || >> >> > + invalid_clockid(clockid)) >> >> > return -EINVAL; >> >> >> >> Oh! Does this mean that in 2.6.2[789] it wasn't possible to use >> >> TFD_TIMER_ABSTIME? >> > >> > No, sorry, my fault. Patch is wrong. In "create" ATM we accept only >> > FCNTL-like flags. In "settime" we get TFD_TIMER_ABSTIME (that needs a >> > check too for EINVAL). >> >> That last piece should be a separate patch, that also gets pushed back >> into -stable. Do you agree? > > Hmm, it's a check for extra bits that do not cause any harm. Dunno if it > fits -stable requirements. You should ask Greg. I agree that it's not a critical fix. The point is of course that if other flags are evntually added to timerfd_settime(), an application needs a way of checking for kernel support / lack of support (a la the recent discussion of eventfd "[patch/rfc] eventfd semaphore-like behavior"). It seems to me it would be good to have that check work as far back as possible in older kernels. If that check is to be added to 2.6.29, it seems reasonable to push it back to the current -stable kernels. Greg? -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git man-pages online: http://www.kernel.org/doc/man-pages/online_pages.html Found a bug? http://www.kernel.org/doc/man-pages/reporting_bugs.html -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
