lkml.org 
[lkml]   [2011]   [Jan]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC] [PATCH 2.6.37-rc5-tip 14/20] 14: uprobes: Handing int3 and singlestep exception.
* Peter Zijlstra <peterz@infradead.org> [2011-01-26 11:17:11]:

> On Wed, 2011-01-26 at 14:22 +0530, Srikar Dronamraju wrote:
> > * Peter Zijlstra <peterz@infradead.org> [2011-01-25 14:56:19]:
> >
> > > On Thu, 2010-12-16 at 15:29 +0530, Srikar Dronamraju wrote:
> > > > + down_read(&mm->mmap_sem);
> > > > + for (vma = mm->mmap; vma; vma = vma->vm_next) {
> > > > + if (!valid_vma(vma))
> > > > + continue;
> > > > + if (probept < vma->vm_start || probept > vma->vm_end)
> > > > + continue;
> > > > + u = find_uprobe(vma->vm_file->f_mapping->host,
> > > > + probept - vma->vm_start);
> > > > + if (u)
> > > > + break;
> > > > + }
> > > > + up_read(&mm->mmap_sem);
> > >
> > > One has to ask, what's wrong with find_vma() ?
> >
> > Are you looking for something like this.
> >
> > down_read(&mm->mmap_sem);
> > for (vma = find_vma(mm, probept); ; vma = vma->vm_next) {
> > if (!valid_vma(vma))
> > continue;
> > u = find_uprobe(vma->vm_file->f_mapping->host,
> > probept - vma->vm_start);
> > if (u)
> > break;
> > }
> > up_read(&mm->mmap_sem);
>
> How could you ever need to iterate here? There is only a single vma that
> covers the probe point, if that doesn't find a uprobe, there isn't any.

Agree.
So it simplifies to

down_read(&mm->mmap_sem);
vma = find_vma(mm, probept);
if (valid_vma(vma)) {
u = find_uprobe(vma->vm_file->f_mapping->host,
probept - vma->vm_start);
}
up_read(&mm->mmap_sem);

--
Thanks and Regards
Srikar


\
 
 \ /
  Last update: 2011-01-26 16:27    [W:0.076 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site