Messages in this thread | | | Date | Wed, 6 Jan 2010 15:20:29 +0800 | From | Wu Fengguang <> | Subject | Re: [PATCH] fs: O_* bit numbers uniqueness check |
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On Wed, Jan 06, 2010 at 03:07:01PM +0800, Eric Dumazet wrote: > Le 06/01/2010 07:55, Wu Fengguang a écrit : > > The O_* bit numbers are defined in 20+ arch/*, and hence can silently > > overlap. Add a boot time check to ensure the uniqueness as suggested > > by David Miller. > > > > CC: David Miller <davem@davemloft.net> > > CC: Stephen Rothwell <sfr@canb.auug.org.au> > > CC: Al Viro <viro@zeniv.linux.org.uk> > > CC: Christoph Hellwig <hch@infradead.org> > > CC: Eric Paris <eparis@redhat.com> > > Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> > > --- > > { > > + /* please add new bits here to ensure allocation uniqueness */ > > + BUG_ON(20 != hweight32( > > + O_RDONLY | O_WRONLY | O_RDWR | > > + O_CREAT | O_EXCL | O_NOCTTY | > > + O_TRUNC | O_APPEND | O_NONBLOCK | > > + O_SYNC | FASYNC | O_DIRECT | > > + O_LARGEFILE | O_DIRECTORY | O_NOFOLLOW | > > + O_NOATIME | O_CLOEXEC | O_RANDOM | > > + FMODE_EXEC | FMODE_NONOTIFY)); > > + > > I cannot test it, but given O_RDONLY is 0, are you sure 20 bits are actually set ?
Yes, I tested it. The tricky one is O_SYNC, which actually has two bits..
Thanks, Fengguang
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