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> > + struct file *file; > > struct pid *pid; > > + struct fd f = fdget(pidfd); > > > > - f = fdget(fd); > > - if (!fd_file(f)) > > + file = fd_file(f); > > + if (!file) > > return ERR_PTR(-EBADF); > > > > - pid = pidfd_pid(fd_file(f)); > > - if (!IS_ERR(pid)) { > > - get_pid(pid); > > - *flags = fd_file(f)->f_flags; > > + pid = pidfd_pid(file); > > + /* If we allow opening a pidfd via /proc/, do so. */ > > + if (IS_ERR(pid) && allow_proc) > > + pid = tgid_pidfd_to_pid(file); > > + > > + if (IS_ERR(pid)) { > > + fdput(f); > > + return pid; > > } > > > > - fdput(f); > > + if (pin_pid) > > + get_pid(pid); > > + else > > + WARN_ON_ONCE(!fd); /* Nothing to keep pid/pidfd around? */ > > + > > + if (flags) > > + *flags = file->f_flags; > > + > > + /* > > + * If the user provides an fd output then it will handle decrementing > > + * its reference counter. > > + */ > > + if (fd) > > + *fd = f; > > + else > > + /* Otherwise we release it. */ > > + fdput(f); > > + > > return pid; > > } > > There is an EXPORT_SYMBOL_GPL(pidfd_get_pid) right after this line. It > should also be changed to EXPORT_SYMBOL_GPL(__pidfd_get_pid), > otherwise __pidfd_get_pid() will not be exported. A module calling > pidfd_get_pid() now inlined in the header file will try to call > __pidfd_get_pid() and will have trouble resolving this symbol. Hmm hang on not there isn't? I don't see that anywhere? [snip]