Messages in this thread | | | Date | Thu, 6 Jan 2005 17:22:48 +0200 | From | "Michael S. Tsirkin" <> | Subject | Re: [PATCH] deprecate (un)register_ioctl32_conversion |
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Hello! Quoting r. Christoph Hellwig (hch@infradead.org) "Re: [PATCH] deprecate (un)register_ioctl32_conversion": > > Stare at this as I might, I dont understand why does it make sence. > > So if filp->f_op is NULL, you are then checking filp->f_op->ioctl? > > Looks like an oops to me. > > I doesn't make sense, but fortunately files with NULL filp->f_op don't > happen in practice (need to research whether it can't happen in theory > either so we could lose lots of checks)
Interesting. At least for character devices coming out of modules I think you dont - you need at least fops->owner.
> --- linux-2.6.10-mm2.orig/fs/compat.c 2005-01-06 11:40:18.831900000 +0100 > +++ linux-2.6.10-mm2/fs/compat.c 2005-01-06 15:50:23.802874672 +0100 > @@ -436,10 +436,10 @@ > if (!filp) > goto out; > > - if (!filp->f_op) { > - if (!filp->f_op->ioctl) > - goto do_ioctl; > - } else if (filp->f_op->compat_ioctl) { > + if (!filp->f_op || !filp->f_op->ioctl) > + goto do_ioctl; > + > + if (filp->f_op || filp->f_op->compat_ioctl) { > error = filp->f_op->compat_ioctl(filp, cmd, arg); > goto out_fput; > }
So now if I dont have ->ioctl the ioctl_compat wont be called. What if I only have unlocked_ioctl?
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