Re: [PATCH v2 2.6.38-rc8-tip 5/20] 5: Uprobes: register/unregister probes.

Peter Zijlstra
2011-03-15T17:51:13Z

On Tue, 2011-03-15 at 13:47 -0400, Steven Rostedt wrote:
> On Tue, 2011-03-15 at 22:45 +0530, Srikar Dronamraju wrote:
> > > > + }
> > > > + list_for_each_entry_safe(mm, tmpmm, &tmp_list, uprobes_list) {
> > > > + down_read(&mm->mmap_sem);
> > > > + if (!install_uprobe(mm, uprobe))
> > > > + ret = 0;
> > >
> > > Installing it once is success ?
> >
> > This is a little tricky. My intention was to return success even if one
> > install is successful. If we return error, then the caller can go
> > ahead and free the consumer. Since we return success if there are
> > currently no processes that have mapped this inode, I was tempted to
> > return success on atleast one successful install.
>
> What about an all or nothing approach. If one fails, remove all that
> were installed, and give up.

That sounds like a much saner semantic and is what we generally do in
the kernel.