* Josh Triplett: > This allows the caller of pipe2 to specify one or both file descriptors > rather than having them automatically use the lowest available file > descriptor. The caller can specify either file descriptor as -1 to > allow that file descriptor to use the lowest available. > > Signed-off-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx> > --- > fs/pipe.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/fs/pipe.c b/fs/pipe.c > index 16fb72e9abf7..4681a0d1d587 100644 > --- a/fs/pipe.c > +++ b/fs/pipe.c > @@ -936,19 +936,19 @@ static int __do_pipe_flags(int *fd, struct file **files, int flags) > int error; > int fdw, fdr; > > - if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT)) > + if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT | O_SPECIFIC_FD)) > return -EINVAL; > > error = create_pipe_files(files, flags); > if (error) > return error; > > - error = get_unused_fd_flags(flags); > + error = get_specific_unused_fd_flags(fd[0], flags); > if (error < 0) > goto err_read_pipe; > fdr = error; > > - error = get_unused_fd_flags(flags); > + error = get_specific_unused_fd_flags(fd[1], flags); > if (error < 0) > goto err_fdr; > fdw = error; > @@ -969,7 +969,11 @@ static int __do_pipe_flags(int *fd, struct file **files, int flags) > int do_pipe_flags(int *fd, int flags) > { > struct file *files[2]; > - int error = __do_pipe_flags(fd, files, flags); > + int error; > + > + if (flags & O_SPECIFIC_FD) > + return -EINVAL; > + error = __do_pipe_flags(fd, files, flags); > if (!error) { > fd_install(fd[0], files[0]); > fd_install(fd[1], files[1]); > @@ -987,6 +991,10 @@ static int do_pipe2(int __user *fildes, int flags) > int fd[2]; > int error; > > + if (flags & O_SPECIFIC_FD) > + if (copy_from_user(fd, fildes, sizeof(fd))) > + return -EFAULT; > + > error = __do_pipe_flags(fd, files, flags); > if (!error) { > if (unlikely(copy_to_user(fildes, fd, sizeof(fd)))) { Mark, I think this will need (or at least benefit from) some valgrind changes.