Re: [PATCH v8 3.2.0-rc5 1/9] uprobes: Install and removebreakpoints.

From: Srikar Dronamraju
Date: Fri Jan 06 2012 - 06:16:14 EST


* Peter Zijlstra <peterz@xxxxxxxxxxxxx> [2012-01-06 11:57:41]:

> On Fri, 2012-01-06 at 11:44 +0530, Srikar Dronamraju wrote:
> > - consumers for the uprobe is NULL, so mmap_uprobe will not
> > insert new breakpoints which correspond to this uprobe until
> > or unless another consumer gets added for the same probe.
> >
> > - If a new consumer gets added for this probe, we reuse the
> > uprobe struct.
>
> Ok, and when we install a new 'first' consumer we'll again try and
> install all breakpoints ignoring those that were already there?
>

Yes, We install breakpoints as if its the first time a probe has been
requested to be installed, including setting the UPROBES_RUN_HANDLER
flag.

We do check if existing breakpoints are around during the actual
insertion, in which case install_breakpoint() will return -EEXIST.
However register assumes EEXIST to be non-fatal, and continues as if its
successful.

--
Thanks and Regards
Srikar

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