Michael S. Tsirkin
2021-Sep-05 15:57 UTC
[PATCH v13 03/13] file: Export receive_fd() to modules
On Tue, Aug 31, 2021 at 06:36:24PM +0800, Xie Yongji wrote:> Export receive_fd() so that some modules can use > it to pass file descriptor between processes without > missing any security stuffs. > > Signed-off-by: Xie Yongji <xieyongji at bytedance.com> > Acked-by: Jason Wang <jasowang at redhat.com>This needs some acks from fs devels. Viro?> --- > fs/file.c | 6 ++++++ > include/linux/file.h | 7 +++---- > 2 files changed, 9 insertions(+), 4 deletions(-) > > diff --git a/fs/file.c b/fs/file.c > index 86dc9956af32..210e540672aa 100644 > --- a/fs/file.c > +++ b/fs/file.c > @@ -1134,6 +1134,12 @@ int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags) > return new_fd; > } > > +int receive_fd(struct file *file, unsigned int o_flags) > +{ > + return __receive_fd(file, NULL, o_flags); > +} > +EXPORT_SYMBOL_GPL(receive_fd); > + > static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags) > { > int err = -EBADF; > diff --git a/include/linux/file.h b/include/linux/file.h > index 2de2e4613d7b..51e830b4fe3a 100644 > --- a/include/linux/file.h > +++ b/include/linux/file.h > @@ -94,6 +94,9 @@ extern void fd_install(unsigned int fd, struct file *file); > > extern int __receive_fd(struct file *file, int __user *ufd, > unsigned int o_flags); > + > +extern int receive_fd(struct file *file, unsigned int o_flags); > + > static inline int receive_fd_user(struct file *file, int __user *ufd, > unsigned int o_flags) > { > @@ -101,10 +104,6 @@ static inline int receive_fd_user(struct file *file, int __user *ufd, > return -EFAULT; > return __receive_fd(file, ufd, o_flags); > } > -static inline int receive_fd(struct file *file, unsigned int o_flags) > -{ > - return __receive_fd(file, NULL, o_flags); > -} > int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags); > > extern void flush_delayed_fput(void); > -- > 2.11.0
On Sun, Sep 05, 2021 at 11:57:22AM -0400, Michael S. Tsirkin wrote:> On Tue, Aug 31, 2021 at 06:36:24PM +0800, Xie Yongji wrote: > > Export receive_fd() so that some modules can use > > it to pass file descriptor between processes without > > missing any security stuffs. > > > > Signed-off-by: Xie Yongji <xieyongji at bytedance.com> > > Acked-by: Jason Wang <jasowang at redhat.com> > > This needs some acks from fs devels. > Viro?*shrug* I still think that having random ioctls messing with descriptor table is a bad idea, and I'm not thrilled with the way it's currently factored, but we can change that later.