Messages in this thread | | | Date | Wed, 11 Feb 2009 17:42:56 +1300 | Subject | Re: [patch] timerfd add flags check | From | Michael Kerrisk <> |
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On Tue, Feb 10, 2009 at 1:36 PM, Michael Kerrisk <mtk.manpages@googlemail.com> wrote: > On Tue, Feb 10, 2009 at 12:31 PM, Davide Libenzi > <davidel@xmailserver.org> wrote: >> Like Michael requested, this patch adds a missing check for valid flags in >> timerfd_settime(), and make it return EINVAL in case some extra bits are >> set. >> >> Michael said: >> If this is to be any use to userland apps that want to check flag >> support (perhaps it is too late already), then the sooner we get it >> into the kernel the better: 2.6.29 would be good; earlier stables as >> well would be even better. >> >> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> >> >> >> Signed-off-by: Davide Libenzi <davidel@xmailserver.org> > > Davide, one question: is the TFD_FLAGS_SET constant below needed?
Davide, Ping! I see Andrew already took the patch, which seems to define this unnecessary macro.
Cheers,
Michael
> >> --- >> fs/timerfd.c | 12 ++++++------ >> include/linux/timerfd.h | 17 ++++++++++++++--- >> 2 files changed, 20 insertions(+), 9 deletions(-) >> >> Index: linux-2.6.mod/fs/timerfd.c >> =================================================================== >> --- linux-2.6.mod.orig/fs/timerfd.c 2009-02-08 18:36:45.000000000 -0800 >> +++ linux-2.6.mod/fs/timerfd.c 2009-02-08 18:53:32.000000000 -0800 >> @@ -186,10 +186,9 @@ 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)) >> - return -EINVAL; >> - if (clockid != CLOCK_MONOTONIC && >> - clockid != CLOCK_REALTIME) >> + if ((flags & ~TFD_CREATE_FLAGS) || >> + (clockid != CLOCK_MONOTONIC && >> + clockid != CLOCK_REALTIME)) >> return -EINVAL; >> >> ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); >> @@ -201,7 +200,7 @@ SYSCALL_DEFINE2(timerfd_create, int, clo >> hrtimer_init(&ctx->tmr, clockid, HRTIMER_MODE_ABS); >> >> ufd = anon_inode_getfd("[timerfd]", &timerfd_fops, ctx, >> - flags & (O_CLOEXEC | O_NONBLOCK)); >> + flags & TFD_SHARED_FCNTL_FLAGS); >> if (ufd < 0) >> kfree(ctx); >> >> @@ -219,7 +218,8 @@ SYSCALL_DEFINE4(timerfd_settime, int, uf >> if (copy_from_user(&ktmr, utmr, sizeof(ktmr))) >> return -EFAULT; >> >> - if (!timespec_valid(&ktmr.it_value) || >> + if ((flags & ~TFD_SETTIME_FLAGS) || >> + !timespec_valid(&ktmr.it_value) || >> !timespec_valid(&ktmr.it_interval)) >> return -EINVAL; >> >> Index: linux-2.6.mod/include/linux/timerfd.h >> =================================================================== >> --- linux-2.6.mod.orig/include/linux/timerfd.h 2009-02-08 18:36:45.000000000 -0800 >> +++ linux-2.6.mod/include/linux/timerfd.h 2009-02-08 18:41:22.000000000 -0800 >> @@ -11,13 +11,24 @@ >> /* For O_CLOEXEC and O_NONBLOCK */ >> #include <linux/fcntl.h> >> >> -/* Flags for timerfd_settime. */ >> +/* >> + * CAREFUL: Check include/asm-generic/fcntl.h when defining >> + * new flags, since they might collide with O_* ones. We want >> + * to re-use O_* flags that couldn't possibly have a meaning >> + * from eventfd, in order to leave a free define-space for >> + * shared O_* flags. >> + */ >> #define TFD_TIMER_ABSTIME (1 << 0) >> - >> -/* Flags for timerfd_create. */ >> #define TFD_CLOEXEC O_CLOEXEC >> #define TFD_NONBLOCK O_NONBLOCK >> >> +#define TFD_SHARED_FCNTL_FLAGS (TFD_CLOEXEC | TFD_NONBLOCK) >> +/* Flags for timerfd_create. */ >> +#define TFD_CREATE_FLAGS TFD_SHARED_FCNTL_FLAGS >> +/* Flags for timerfd_settime. */ >> +#define TFD_SETTIME_FLAGS TFD_TIMER_ABSTIME >> +#define TFD_FLAGS_SET (TFD_SHARED_FCNTL_FLAGS | TFD_TIMER_ABSTIME) >> + >> >> #endif /* _LINUX_TIMERFD_H */ >> >> > > > > -- > 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 >
-- 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
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