Messages in this thread | | | Subject | Re: [PATCH v8 3.2.0-rc5 1/9] uprobes: Install and remove breakpoints. | From | Peter Zijlstra <> | Date | Wed, 04 Jan 2012 17:51:56 +0100 |
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On Fri, 2011-12-16 at 17:58 +0530, Srikar Dronamraju wrote: > +static int register_for_each_vma(struct uprobe *uprobe, bool is_register) > +{ > + struct list_head try_list; > + struct vm_area_struct *vma; > + struct address_space *mapping; > + struct vma_info *vi, *tmpvi; > + struct mm_struct *mm; > + loff_t vaddr; > + int ret = 0; > + > + mapping = uprobe->inode->i_mapping; > + INIT_LIST_HEAD(&try_list); > + while ((vi = find_next_vma_info(&try_list, uprobe->offset, > + mapping, is_register)) != NULL) { > + if (IS_ERR(vi)) { > + ret = PTR_ERR(vi); > + break; > + } > + mm = vi->mm; > + down_read(&mm->mmap_sem); > + vma = find_vma(mm, (unsigned long)vi->vaddr); > + if (!vma || !valid_vma(vma, is_register)) { > + list_del(&vi->probe_list); > + kfree(vi); > + up_read(&mm->mmap_sem); > + mmput(mm); > + continue; > + } > + vaddr = vma_address(vma, uprobe->offset); > + if (vma->vm_file->f_mapping->host != uprobe->inode || > + vaddr != vi->vaddr) { > + list_del(&vi->probe_list); > + kfree(vi); > + up_read(&mm->mmap_sem); > + mmput(mm); > + continue; > + } > + > + if (is_register) > + ret = install_breakpoint(mm, uprobe, vma, vi->vaddr); > + else > + remove_breakpoint(mm, uprobe, vi->vaddr); > + > + up_read(&mm->mmap_sem); > + mmput(mm); > + if (is_register) { > + if (ret && ret == -EEXIST) > + ret = 0; > + if (ret) > + break; > + }
Since you init ret := 0 and remove_breakpoint doesn't change it, this conditional on is_register is superfluous.
> + } > + list_for_each_entry_safe(vi, tmpvi, &try_list, probe_list) { > + list_del(&vi->probe_list); > + kfree(vi); > + } > + return ret; > +}
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