Hmm. On closer inspection this patch touches on a greater inconsistency then the test to see if the task is the only task using the mm_struct.
We currently allow tasks created with clone to have a different user namespace and to share a mm_struct, and I don't think that is wrong. What we actually care about are the uid and gid values that show up in signals that are reported to a process, and for that what we care about is the question do the tasks share signal handling state, which is controlled by the flags CLONE_SIGHAND and CLONE_THREAD. As such current_is_single_threaded() is wrong because it tests to see if there is someone else sharing an mm_struct. So I have to ask. Is it possible to rework these checks such that we look at the sighand struct and signal sharing handling sharing instead of the count on the mm_struct? I suspect we could do that more cheaply, as well as making the code more correct. Eric -- 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/
