Mailing List Archive: [PATCH v10 02/17] file: Export receive

[PATCH v10 02/17] file: Export receive_fd() to modules

Jul 29, 2021, 1:05 AM

Post #1 of 4 (10 views)

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@bytedance.com>
---
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

Re: [PATCH v10 02/17] file: Export receive_fd() to modules [ In reply to ]

jasowang at redhat

Aug 3, 2021, 1:05 AM

Post #2 of 4 (10 views)

Permalink

?? 2021/7/29 ????3:34, Xie Yongji ???:
> 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@bytedance.com>
> ---
> 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);

Any reason that receive_fd_user() can live in the file.h?

Thanks

> +}
> +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);

Re: [PATCH v10 02/17] file: Export receive_fd() to modules [ In reply to ]

xieyongji at bytedance

Aug 3, 2021, 2:15 AM

Post #3 of 4 (10 views)

Permalink

On Tue, Aug 3, 2021 at 3:46 PM Jason Wang <jasowang@redhat.com> wrote:
>
>
> ? 2021/7/29 ??3:34, Xie Yongji ??:
> > 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@bytedance.com>
> > ---
> > 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);
>
>
> Any reason that receive_fd_user() can live in the file.h?
>

Since no modules use it.

Thanks,
Yongji

Re: [PATCH v10 02/17] file: Export receive_fd() to modules [ In reply to ]

jasowang at redhat

Aug 4, 2021, 2:15 AM

Post #4 of 4 (10 views)

Permalink

? 2021/8/3 ??5:01, Yongji Xie ??:
> On Tue, Aug 3, 2021 at 3:46 PM Jason Wang <jasowang@redhat.com> wrote:
>>
>> ? 2021/7/29 ??3:34, Xie Yongji ??:
>>> 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@bytedance.com>
>>> ---
>>> 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);
>>
>> Any reason that receive_fd_user() can live in the file.h?
>>
> Since no modules use it.
>
> Thanks,
> Yongji

Ok.

Acked-by: Jason Wang <jasowang@redhat.com>

>