On 10/29, Namhyung Kim wrote:
>
> +static void __user *get_user_vaddr(unsigned long addr, struct trace_uprobe 
> *tu)
> +{
> +     unsigned long pgoff = addr >> PAGE_SHIFT;
> +     struct vm_area_struct *vma;
> +     struct address_space *mapping;
> +     unsigned long vaddr = 0;
> +
> +     if (tu == NULL) {
> +             /* A NULL tu means that we already got the vaddr */
> +             return (void __force __user *) addr;
> +     }
> +
> +     mapping = tu->inode->i_mapping;
> +
> +     mutex_lock(&mapping->i_mmap_mutex);
> +     vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
> +             if (vma->vm_mm != current->mm)
> +                     continue;
> +             if (!(vma->vm_flags & VM_READ))
> +                     continue;
> +
> +             vaddr = offset_to_vaddr(vma, addr);
> +             break;
> +     }
> +     mutex_unlock(&mapping->i_mmap_mutex);
> +
> +     WARN_ON_ONCE(vaddr == 0);

Hmm. But unless I missed something this "addr" passed as an argument can
be wrong? And if nothing else this or another thread can unmap the vma?

Oleg.

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