Re: [PATCH v5 3.1.0-rc4-tip 4/26] uprobes: Define hooks formmap/munmap.

[Srikar Dronamraju]

* Stefan Hajnoczi <stefanha@xxxxxxxxxxxxxxxxxx> [2011-09-20 18:03:10]:

> On Tue, Sep 20, 2011 at 05:30:40PM +0530, Srikar Dronamraju wrote:
> > +static void build_probe_list(struct inode *inode, struct list_head *head)
> > +{
> > +	struct uprobe *uprobe;
> > +	struct rb_node *n;
> > +	unsigned long flags;
> > +
> > +	n = uprobes_tree.rb_node;
> > +	spin_lock_irqsave(&uprobes_treelock, flags);
> 
> Not sure whether grabbing root.rb_node outside the spinlock is safe?  If
> the tree is rotated on another CPU you could catch and out-of-date node?


Agree that its better to access the node in the spinlock.
Shall correct this.
 
> > +static void dec_mm_uprobes_count(struct vm_area_struct *vma,
> > +		struct inode *inode)
> > +{
> > +	struct uprobe *uprobe;
> > +	struct rb_node *n;
> > +	unsigned long flags;
> > +
> > +	n = uprobes_tree.rb_node;
> > +	spin_lock_irqsave(&uprobes_treelock, flags);
> 
> Same here.

Okay.

-- 
Thanks and Regards
Srikar
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