* Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > On Wed, Oct 02, 2013 at 07:13:19AM +0200, Ingo Molnar wrote: > > > > * Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > > > > On Tue, Oct 01, 2013 at 02:41:58PM -0700, Eric Dumazet wrote: > > > > Maybe I am missing something obvious ? > > > > > > Yes. do_execve_common() starts with unshare_files(); there can be > > > no other thread capable of modifying that descriptor table. > > > > Btw., might the Android Binder: > > > > drivers/staging/android/binder.c: struct files_struct *files = proc->files; > > ... > > drivers/staging/android/binder.c: __fd_install(proc->files, fd, file); > > ... > > drivers/staging/android/binder.c: retval = __close_fd(proc->files, fd); > > > > violate that assumption? > > Not unless your thread has managed to call an ioctl between entering > do_execve_common() and calling do_close_on_exec() ;-) Indeed - while the binder interface appears to allow the insertion of fds into other task's file tables, it refcounts its task->files access and only ever receives it via get_files_struct(current), so it cannot possibly interfere with a private file table resulting from unshare_files(). Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
