On Thu, 2011-06-16 at 20:23 +0200, Peter Zijlstra wrote: > int __register_uprobe(...) > { > uprobe = alloc_uprobe(...); // find or insert in tree > > vma_prio_tree_foreach(..) { > // get mm ref, add to list blah blah > } > > list_for_each_entry_safe() { > // del from list etc.. > down_read(mm->mmap_sem); > ret = install_breakpoint(); > if (ret && (ret != -ESRCH || ret != -EEXIST)) { > up_read(..); > goto fail; > } > > return 0; > > fail: > list_for_each_entry_safe() { > // del from list, put mm > } > > return ret; > } > > void __unregister_uprobe(...) > { > uprobe = find_uprobe(); // ref++ > if (delete_consumer(...)); // includes tree removal on last consumer > // implies we own the last ref > return; // consumers > > vma_prio_tree_foreach() { > // create list > } > > list_for_each_entry_safe() { > // remove from list > remove_breakpoint(); // unconditional, if it wasn't there > // its a nop anyway, can't get any new > // new probes on account of holding > // uprobes_mutex and mmap() doesn't see > // it due to tree removal. > } put_uprobe(); // last ref, *poof* > } > > int register_uprobe(...) > { > int ret; > > mutex_lock(&uprobes_mutex); > ret = __register_uprobe(...); > if (!ret) > __unregister_uprobe(...); > mutex_unlock(&uprobes_mutex); > > ret; > } > > int mmap_uprobe(...) > { > spin_lock(&uprobes_treelock); > for_each_probe_in_inode() { > // create list; > } > spin_unlock(..); > > list_for_each_entry_safe() { > // remove from list > ret = install_breakpoint(); > if (ret) > goto fail; > if (!uprobe_still_there()) // takes treelock > remove_breakpoint(); > } > > return 0; > > fail: > list_for_each_entry_safe() { > // destroy list > } > return ret; > } -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href