Re: [PATCH v5 3.1.0-rc4-tip 26/26] uprobes: queue signals whilethread is singlestepping.

From: Srikar Dronamraju
Date: Thu Oct 06 2011 - 02:04:45 EST

* Oleg Nesterov <oleg@xxxxxxxxxx> [2011-10-05 20:01:39]:

> Srikar, I am still reading this series, need more time to read this
> patch, but:


> On 09/27, Srikar Dronamraju wrote:
> >
> > I did a rethink and implemented this patch a little differently using
> > block_all_signals, unblock_all_signals. This wouldnt need the
> > #ifdeffery + no changes in kernel/signal.c
> No, Please don't. block_all_signals() must be killed. This interface
> simply do not work. At all. It is buggy as hell. I guess I should ping
> David Airlie again.

I could use sigprocmask instead of block_all_signals.

The patch (that I sent out as part of v5 patchset) uses per task
pending sigqueue and start queueing the signals when the task
singlesteps. After completion of singlestep, walks thro the pending

But I was thinking if I should block signals instead of queueing them in
a different sigqueue. So Idea is to block signals just before the task
enables singlestep and unblock after task disables singlestep.

Instead of using block_all_signals, I could use sigprocmask to achieve
the same.

Which approach do you suggest or do you have any other approach to look

Thanks and Regards

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