Messages in this thread | | | Date | Fri, 28 Jun 2013 17:22:24 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/5] perf: fix broken union in perf_event_mmap_page |
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On Fri, Jun 28, 2013 at 04:22:17PM +0300, Adrian Hunter wrote: > The capabilities bits must not be "union'ed" together. > Put them in a separate struct. > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > include/uapi/linux/perf_event.h | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h > index 0b1df41..19f6ee5 100644 > --- a/include/uapi/linux/perf_event.h > +++ b/include/uapi/linux/perf_event.h > @@ -375,9 +375,11 @@ struct perf_event_mmap_page { > __u64 time_running; /* time event on cpu */ > union { > __u64 capabilities; > - __u64 cap_usr_time : 1, > - cap_usr_rdpmc : 1, > - cap_____res : 62; > + struct { > + __u64 cap_usr_time : 1, > + cap_usr_rdpmc : 1, > + cap_____res : 62; > + }; > };
Ick, it did that!? and here I thought there was a difference between:
int foo:1, bar:1;
and
int foo:1; int bar:1;
That made all the difference in this particular case. I guess I should go read the language spec more carefully next time.
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