Re: [PATCH 5/5] uprobes: kill insert_vm_struct()->uprobe_mmap()
* Oleg Nesterov [2012-07-13 15:29:16]:
> On 07/13, Srikar Dronamraju wrote:
> >
> > * Oleg Nesterov [2012-07-08 22:30:11]:
> >
> > > Kill insert_vm_struct()->uprobe_mmap(). It is not needed, nobody
> > > except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with
> > > vma->vm_file != NULL.
> > >
> >
> > Right, but somebody else might start using this later.
>
> Unlikely, I think...
>
> > I cant think of a use case though.
>
> Yes.
>
> > > And it is wrong. Again, get_user_pages() can not succeed before
> > > vma_link(vma) makes is visible to find_vma(). And even if this
> > > worked, we must not insert the new bp before this mapping is
> > > visible to vma_prio_tree_foreach() for uprobe_unregister().
> > >
> >
> > Agree, we are wrong to do it before vma_link.
> >
> >
> > > Signed-off-by: Oleg Nesterov
> > > ---
> > > mm/mmap.c |3 ---
> > > 1 files changed, 0 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/mm/mmap.c b/mm/mmap.c
> > > index e5a4614..4fe2697 100644
> > > --- a/mm/mmap.c
> > > +++ b/mm/mmap.c
> > > @@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct
> > > vm_area_struct * vma)
> > >security_vm_enough_memory_mm(mm, vma_pages(vma)))
> > > return -ENOMEM;
> > >
> > > - if (vma->vm_file && uprobe_mmap(vma))
> > > - return -EINVAL;
> > > -
> > > vma_link(mm, vma, prev, rb_link, rb_parent);
> > > return 0;
> > > }
> >
> > Can we do something like:
> >
> > vma_link(mm, vma, prev, rb_link, rb_parent);
> >
> > if (vma->vm_file && uprobe_mmap(vma)) {
> > /* FIXME: dont know if calling unmap_region is fine here */
> > unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
> > return -EINVAL;
> > }
>
> Yes, I was thinking about the possible fix, but afaics this is not
> enough. At least this needs vm_unacct_memory(). And I am not sure
> about unmap_region...
>
> The main problem is that I have no idea how could I test the fix.
> Once again, currently this file can't be probed.
>
> So. Can't we kill this obviously wrong and unneeded (at least currently)
> code? Currently uprobe_mmap/munmap logic is not correct (I'll try to send
> more fixes after I return from vacation), it would be nice to remove the
> callsite.
>
> If somebody else will use insert_vm_struct() to mmap the can-be-uprobed
> file then yes, we will need to add uprobe_mmap() somewhere. But until
> then, the right fix is not clear and not testable.
Yes, for now your solution should be the way to go.
May be we should probably add a TODO/Fixme comment in insert_vm_struct
saying anybody trying to use insert_vm_struct to look at uprobe_mmap().
--
Thanks and Regards
Srikar
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] uprobes: kill insert_vm_struct()->uprobe_mmap()
* Oleg Nesterov [2012-07-08 22:30:11]: > Kill insert_vm_struct()->uprobe_mmap(). It is not needed, nobody > except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with > vma->vm_file != NULL. > > And it is wrong. Again, get_user_pages() can not succeed before > vma_link(vma) makes is visible to find_vma(). And even if this > worked, we must not insert the new bp before this mapping is > visible to vma_prio_tree_foreach() for uprobe_unregister(). > > Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju > --- > mm/mmap.c |3 --- > 1 files changed, 0 insertions(+), 3 deletions(-) > > diff --git a/mm/mmap.c b/mm/mmap.c > index e5a4614..4fe2697 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct > vm_area_struct * vma) >security_vm_enough_memory_mm(mm, vma_pages(vma))) > return -ENOMEM; > > - if (vma->vm_file && uprobe_mmap(vma)) > - return -EINVAL; > - > vma_link(mm, vma, prev, rb_link, rb_parent); > return 0; > } > -- > 1.5.5.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] uprobes: kill insert_vm_struct()->uprobe_mmap()
On 07/13, Srikar Dronamraju wrote:
>
> * Oleg Nesterov [2012-07-08 22:30:11]:
>
> > Kill insert_vm_struct()->uprobe_mmap(). It is not needed, nobody
> > except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with
> > vma->vm_file != NULL.
> >
>
> Right, but somebody else might start using this later.
Unlikely, I think...
> I cant think of a use case though.
Yes.
> > And it is wrong. Again, get_user_pages() can not succeed before
> > vma_link(vma) makes is visible to find_vma(). And even if this
> > worked, we must not insert the new bp before this mapping is
> > visible to vma_prio_tree_foreach() for uprobe_unregister().
> >
>
> Agree, we are wrong to do it before vma_link.
>
>
> > Signed-off-by: Oleg Nesterov
> > ---
> > mm/mmap.c |3 ---
> > 1 files changed, 0 insertions(+), 3 deletions(-)
> >
> > diff --git a/mm/mmap.c b/mm/mmap.c
> > index e5a4614..4fe2697 100644
> > --- a/mm/mmap.c
> > +++ b/mm/mmap.c
> > @@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct
> > vm_area_struct * vma)
> > security_vm_enough_memory_mm(mm, vma_pages(vma)))
> > return -ENOMEM;
> >
> > - if (vma->vm_file && uprobe_mmap(vma))
> > - return -EINVAL;
> > -
> > vma_link(mm, vma, prev, rb_link, rb_parent);
> > return 0;
> > }
>
> Can we do something like:
>
> vma_link(mm, vma, prev, rb_link, rb_parent);
>
> if (vma->vm_file && uprobe_mmap(vma)) {
> /* FIXME: dont know if calling unmap_region is fine here */
> unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
> return -EINVAL;
> }
Yes, I was thinking about the possible fix, but afaics this is not
enough. At least this needs vm_unacct_memory(). And I am not sure
about unmap_region...
The main problem is that I have no idea how could I test the fix.
Once again, currently this file can't be probed.
So. Can't we kill this obviously wrong and unneeded (at least currently)
code? Currently uprobe_mmap/munmap logic is not correct (I'll try to send
more fixes after I return from vacation), it would be nice to remove the
callsite.
If somebody else will use insert_vm_struct() to mmap the can-be-uprobed
file then yes, we will need to add uprobe_mmap() somewhere. But until
then, the right fix is not clear and not testable.
Oleg.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] uprobes: kill insert_vm_struct()->uprobe_mmap()
* Oleg Nesterov [2012-07-08 22:30:11]:
> Kill insert_vm_struct()->uprobe_mmap(). It is not needed, nobody
> except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with
> vma->vm_file != NULL.
>
Right, but somebody else might start using this later.
I cant think of a use case though.
> And it is wrong. Again, get_user_pages() can not succeed before
> vma_link(vma) makes is visible to find_vma(). And even if this
> worked, we must not insert the new bp before this mapping is
> visible to vma_prio_tree_foreach() for uprobe_unregister().
>
Agree, we are wrong to do it before vma_link.
> Signed-off-by: Oleg Nesterov
> ---
> mm/mmap.c |3 ---
> 1 files changed, 0 insertions(+), 3 deletions(-)
>
> diff --git a/mm/mmap.c b/mm/mmap.c
> index e5a4614..4fe2697 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct
> vm_area_struct * vma)
>security_vm_enough_memory_mm(mm, vma_pages(vma)))
> return -ENOMEM;
>
> - if (vma->vm_file && uprobe_mmap(vma))
> - return -EINVAL;
> -
> vma_link(mm, vma, prev, rb_link, rb_parent);
> return 0;
> }
Can we do something like:
vma_link(mm, vma, prev, rb_link, rb_parent);
if (vma->vm_file && uprobe_mmap(vma)) {
/* FIXME: dont know if calling unmap_region is fine here */
unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
return -EINVAL;
}
return 0;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] uprobes: kill insert_vm_struct()-uprobe_mmap()
* Oleg Nesterov o...@redhat.com [2012-07-08 22:30:11]:
Kill insert_vm_struct()-uprobe_mmap(). It is not needed, nobody
except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with
vma-vm_file != NULL.
Right, but somebody else might start using this later.
I cant think of a use case though.
And it is wrong. Again, get_user_pages() can not succeed before
vma_link(vma) makes is visible to find_vma(). And even if this
worked, we must not insert the new bp before this mapping is
visible to vma_prio_tree_foreach() for uprobe_unregister().
Agree, we are wrong to do it before vma_link.
Signed-off-by: Oleg Nesterov o...@redhat.com
---
mm/mmap.c |3 ---
1 files changed, 0 insertions(+), 3 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index e5a4614..4fe2697 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct
vm_area_struct * vma)
security_vm_enough_memory_mm(mm, vma_pages(vma)))
return -ENOMEM;
- if (vma-vm_file uprobe_mmap(vma))
- return -EINVAL;
-
vma_link(mm, vma, prev, rb_link, rb_parent);
return 0;
}
Can we do something like:
vma_link(mm, vma, prev, rb_link, rb_parent);
if (vma-vm_file uprobe_mmap(vma)) {
/* FIXME: dont know if calling unmap_region is fine here */
unmap_region(mm, vma, prev, vma-vm_start, vma-vm_end);
return -EINVAL;
}
return 0;
}
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] uprobes: kill insert_vm_struct()-uprobe_mmap()
On 07/13, Srikar Dronamraju wrote:
* Oleg Nesterov o...@redhat.com [2012-07-08 22:30:11]:
Kill insert_vm_struct()-uprobe_mmap(). It is not needed, nobody
except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with
vma-vm_file != NULL.
Right, but somebody else might start using this later.
Unlikely, I think...
I cant think of a use case though.
Yes.
And it is wrong. Again, get_user_pages() can not succeed before
vma_link(vma) makes is visible to find_vma(). And even if this
worked, we must not insert the new bp before this mapping is
visible to vma_prio_tree_foreach() for uprobe_unregister().
Agree, we are wrong to do it before vma_link.
Signed-off-by: Oleg Nesterov o...@redhat.com
---
mm/mmap.c |3 ---
1 files changed, 0 insertions(+), 3 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index e5a4614..4fe2697 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct
vm_area_struct * vma)
security_vm_enough_memory_mm(mm, vma_pages(vma)))
return -ENOMEM;
- if (vma-vm_file uprobe_mmap(vma))
- return -EINVAL;
-
vma_link(mm, vma, prev, rb_link, rb_parent);
return 0;
}
Can we do something like:
vma_link(mm, vma, prev, rb_link, rb_parent);
if (vma-vm_file uprobe_mmap(vma)) {
/* FIXME: dont know if calling unmap_region is fine here */
unmap_region(mm, vma, prev, vma-vm_start, vma-vm_end);
return -EINVAL;
}
Yes, I was thinking about the possible fix, but afaics this is not
enough. At least this needs vm_unacct_memory(). And I am not sure
about unmap_region...
The main problem is that I have no idea how could I test the fix.
Once again, currently this file can't be probed.
So. Can't we kill this obviously wrong and unneeded (at least currently)
code? Currently uprobe_mmap/munmap logic is not correct (I'll try to send
more fixes after I return from vacation), it would be nice to remove the
callsite.
If somebody else will use insert_vm_struct() to mmap the can-be-uprobed
file then yes, we will need to add uprobe_mmap() somewhere. But until
then, the right fix is not clear and not testable.
Oleg.
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] uprobes: kill insert_vm_struct()-uprobe_mmap()
* Oleg Nesterov o...@redhat.com [2012-07-08 22:30:11]: Kill insert_vm_struct()-uprobe_mmap(). It is not needed, nobody except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with vma-vm_file != NULL. And it is wrong. Again, get_user_pages() can not succeed before vma_link(vma) makes is visible to find_vma(). And even if this worked, we must not insert the new bp before this mapping is visible to vma_prio_tree_foreach() for uprobe_unregister(). Signed-off-by: Oleg Nesterov o...@redhat.com Acked-by: Srikar Dronamraju sri...@linux.vnet.ibm.com --- mm/mmap.c |3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index e5a4614..4fe2697 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma) security_vm_enough_memory_mm(mm, vma_pages(vma))) return -ENOMEM; - if (vma-vm_file uprobe_mmap(vma)) - return -EINVAL; - vma_link(mm, vma, prev, rb_link, rb_parent); return 0; } -- 1.5.5.1 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 5/5] uprobes: kill insert_vm_struct()-uprobe_mmap()
* Oleg Nesterov o...@redhat.com [2012-07-13 15:29:16]:
On 07/13, Srikar Dronamraju wrote:
* Oleg Nesterov o...@redhat.com [2012-07-08 22:30:11]:
Kill insert_vm_struct()-uprobe_mmap(). It is not needed, nobody
except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with
vma-vm_file != NULL.
Right, but somebody else might start using this later.
Unlikely, I think...
I cant think of a use case though.
Yes.
And it is wrong. Again, get_user_pages() can not succeed before
vma_link(vma) makes is visible to find_vma(). And even if this
worked, we must not insert the new bp before this mapping is
visible to vma_prio_tree_foreach() for uprobe_unregister().
Agree, we are wrong to do it before vma_link.
Signed-off-by: Oleg Nesterov o...@redhat.com
---
mm/mmap.c |3 ---
1 files changed, 0 insertions(+), 3 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index e5a4614..4fe2697 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct
vm_area_struct * vma)
security_vm_enough_memory_mm(mm, vma_pages(vma)))
return -ENOMEM;
- if (vma-vm_file uprobe_mmap(vma))
- return -EINVAL;
-
vma_link(mm, vma, prev, rb_link, rb_parent);
return 0;
}
Can we do something like:
vma_link(mm, vma, prev, rb_link, rb_parent);
if (vma-vm_file uprobe_mmap(vma)) {
/* FIXME: dont know if calling unmap_region is fine here */
unmap_region(mm, vma, prev, vma-vm_start, vma-vm_end);
return -EINVAL;
}
Yes, I was thinking about the possible fix, but afaics this is not
enough. At least this needs vm_unacct_memory(). And I am not sure
about unmap_region...
The main problem is that I have no idea how could I test the fix.
Once again, currently this file can't be probed.
So. Can't we kill this obviously wrong and unneeded (at least currently)
code? Currently uprobe_mmap/munmap logic is not correct (I'll try to send
more fixes after I return from vacation), it would be nice to remove the
callsite.
If somebody else will use insert_vm_struct() to mmap the can-be-uprobed
file then yes, we will need to add uprobe_mmap() somewhere. But until
then, the right fix is not clear and not testable.
Yes, for now your solution should be the way to go.
May be we should probably add a TODO/Fixme comment in insert_vm_struct
saying anybody trying to use insert_vm_struct to look at uprobe_mmap().
--
Thanks and Regards
Srikar
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH 5/5] uprobes: kill insert_vm_struct()->uprobe_mmap()
Kill insert_vm_struct()->uprobe_mmap(). It is not needed, nobody except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with vma->vm_file != NULL. And it is wrong. Again, get_user_pages() can not succeed before vma_link(vma) makes is visible to find_vma(). And even if this worked, we must not insert the new bp before this mapping is visible to vma_prio_tree_foreach() for uprobe_unregister(). Signed-off-by: Oleg Nesterov --- mm/mmap.c |3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index e5a4614..4fe2697 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma) security_vm_enough_memory_mm(mm, vma_pages(vma))) return -ENOMEM; - if (vma->vm_file && uprobe_mmap(vma)) - return -EINVAL; - vma_link(mm, vma, prev, rb_link, rb_parent); return 0; } -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 5/5] uprobes: kill insert_vm_struct()-uprobe_mmap()
Kill insert_vm_struct()-uprobe_mmap(). It is not needed, nobody except arch/ia64/kernel/perfmon.c uses insert_vm_struct(vma) with vma-vm_file != NULL. And it is wrong. Again, get_user_pages() can not succeed before vma_link(vma) makes is visible to find_vma(). And even if this worked, we must not insert the new bp before this mapping is visible to vma_prio_tree_foreach() for uprobe_unregister(). Signed-off-by: Oleg Nesterov o...@redhat.com --- mm/mmap.c |3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index e5a4614..4fe2697 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2345,9 +2345,6 @@ int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma) security_vm_enough_memory_mm(mm, vma_pages(vma))) return -ENOMEM; - if (vma-vm_file uprobe_mmap(vma)) - return -EINVAL; - vma_link(mm, vma, prev, rb_link, rb_parent); return 0; } -- 1.5.5.1 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
