Messages in this thread |  | | | Date | Fri, 13 Jul 2012 13:41:03 +0530 | | From | Srikar Dronamraju <> | | Subject | Re: [PATCH 5/5] uprobes: kill insert_vm_struct()->uprobe_mmap() |
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* Oleg Nesterov <oleg@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 <oleg@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;
}
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