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Message-ID: <aAjL-1rB3YHMnr9F@gallifrey>
Date: Wed, 23 Apr 2025 11:16:11 +0000
From: "Dr. David Alan Gilbert" <linux@...blig.org>
To: Arnaud POULIQUEN <arnaud.pouliquen@...s.st.com>
Cc: andersson@...nel.org, mathieu.poirier@...aro.org, corbet@....net,
linux-remoteproc@...r.kernel.org, linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] rpmsg: core: Remove deadcode
* Arnaud POULIQUEN (arnaud.pouliquen@...s.st.com) wrote:
> Hello,
>
> On 4/20/25 22:41, linux@...blig.org wrote:
> > From: "Dr. David Alan Gilbert" <linux@...blig.org>
> >
> > rpmsg_send_offchannel() and rpmsg_trysend_offchannel() have been
> > unused since they were added in 2011's
> > commit bcabbccabffe ("rpmsg: add virtio-based remote processor messaging
> > bus")
> >
> > Remove them and associated docs.
> >
> > I suspect this means the trysend_offchannel and send_offchannel
> > member function pointers and the virtio implementation of them can be
> > removed as well, but haven't yet gone that far.
>
> It seems to me that this API is not safe as it allows an endpoint to usurp the
> identity of another one thanks to the source address.
>
> So, +1 to remove it.
>
> That said, to complete the remove it would be nice to also remove associated ops
> declared in rpmsg_endpoint_ops and implemented in virtio_rpmsg_bus.c.
OK, yes I was thinking that but wasn't sure - I'll cut some follow up patches
Dave
> Regards,
> Arnaud
>
>
> >
> > Signed-off-by: Dr. David Alan Gilbert <linux@...blig.org>
> > ---
> > Documentation/staging/rpmsg.rst | 46 ------------------------
> > drivers/rpmsg/rpmsg_core.c | 63 ---------------------------------
> > include/linux/rpmsg.h | 22 ------------
> > 3 files changed, 131 deletions(-)
> >
> > diff --git a/Documentation/staging/rpmsg.rst b/Documentation/staging/rpmsg.rst
> > index 3713adaa1608..40282cca86ca 100644
> > --- a/Documentation/staging/rpmsg.rst
> > +++ b/Documentation/staging/rpmsg.rst
> > @@ -110,31 +110,6 @@ or a timeout of 15 seconds elapses. When the latter happens,
> > The function can only be called from a process context (for now).
> > Returns 0 on success and an appropriate error value on failure.
> >
> > -::
> > -
> > - int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
> > - void *data, int len);
> > -
> > -
> > -sends a message across to the remote processor, using the src and dst
> > -addresses provided by the user.
> > -
> > -The caller should specify the endpoint, the data it wants to send,
> > -its length (in bytes), and explicit source and destination addresses.
> > -The message will then be sent to the remote processor to which the
> > -endpoint's channel belongs, but the endpoint's src and channel dst
> > -addresses will be ignored (and the user-provided addresses will
> > -be used instead).
> > -
> > -In case there are no TX buffers available, the function will block until
> > -one becomes available (i.e. until the remote processor consumes
> > -a tx buffer and puts it back on virtio's used descriptor ring),
> > -or a timeout of 15 seconds elapses. When the latter happens,
> > --ERESTARTSYS is returned.
> > -
> > -The function can only be called from a process context (for now).
> > -Returns 0 on success and an appropriate error value on failure.
> > -
> > ::
> >
> > int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
> > @@ -173,27 +148,6 @@ return -ENOMEM without waiting until one becomes available.
> > The function can only be called from a process context (for now).
> > Returns 0 on success and an appropriate error value on failure.
> >
> > -::
> > -
> > - int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
> > - void *data, int len);
> > -
> > -
> > -sends a message across to the remote processor, using source and
> > -destination addresses provided by the user.
> > -
> > -The user should specify the channel, the data it wants to send,
> > -its length (in bytes), and explicit source and destination addresses.
> > -The message will then be sent to the remote processor to which the
> > -channel belongs, but the channel's src and dst addresses will be
> > -ignored (and the user-provided addresses will be used instead).
> > -
> > -In case there are no TX buffers available, the function will immediately
> > -return -ENOMEM without waiting until one becomes available.
> > -
> > -The function can only be called from a process context (for now).
> > -Returns 0 on success and an appropriate error value on failure.
> > -
> > ::
> >
> > struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
> > diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
> > index 207b64c0a2fe..6ee36adcbdba 100644
> > --- a/drivers/rpmsg/rpmsg_core.c
> > +++ b/drivers/rpmsg/rpmsg_core.c
> > @@ -193,38 +193,6 @@ int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
> > }
> > EXPORT_SYMBOL(rpmsg_sendto);
> >
> > -/**
> > - * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
> > - * @ept: the rpmsg endpoint
> > - * @src: source address
> > - * @dst: destination address
> > - * @data: payload of message
> > - * @len: length of payload
> > - *
> > - * This function sends @data of length @len to the remote @dst address,
> > - * and uses @src as the source address.
> > - * The message will be sent to the remote processor which the @ept
> > - * endpoint belongs to.
> > - * In case there are no TX buffers available, the function will block until
> > - * one becomes available, or a timeout of 15 seconds elapses. When the latter
> > - * happens, -ERESTARTSYS is returned.
> > - *
> > - * Can only be called from process context (for now).
> > - *
> > - * Return: 0 on success and an appropriate error value on failure.
> > - */
> > -int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
> > - void *data, int len)
> > -{
> > - if (WARN_ON(!ept))
> > - return -EINVAL;
> > - if (!ept->ops->send_offchannel)
> > - return -ENXIO;
> > -
> > - return ept->ops->send_offchannel(ept, src, dst, data, len);
> > -}
> > -EXPORT_SYMBOL(rpmsg_send_offchannel);
> > -
> > /**
> > * rpmsg_trysend() - send a message across to the remote processor
> > * @ept: the rpmsg endpoint
> > @@ -301,37 +269,6 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
> > }
> > EXPORT_SYMBOL(rpmsg_poll);
> >
> > -/**
> > - * rpmsg_trysend_offchannel() - send a message using explicit src/dst addresses
> > - * @ept: the rpmsg endpoint
> > - * @src: source address
> > - * @dst: destination address
> > - * @data: payload of message
> > - * @len: length of payload
> > - *
> > - * This function sends @data of length @len to the remote @dst address,
> > - * and uses @src as the source address.
> > - * The message will be sent to the remote processor which the @ept
> > - * endpoint belongs to.
> > - * In case there are no TX buffers available, the function will immediately
> > - * return -ENOMEM without waiting until one becomes available.
> > - *
> > - * Can only be called from process context (for now).
> > - *
> > - * Return: 0 on success and an appropriate error value on failure.
> > - */
> > -int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
> > - void *data, int len)
> > -{
> > - if (WARN_ON(!ept))
> > - return -EINVAL;
> > - if (!ept->ops->trysend_offchannel)
> > - return -ENXIO;
> > -
> > - return ept->ops->trysend_offchannel(ept, src, dst, data, len);
> > -}
> > -EXPORT_SYMBOL(rpmsg_trysend_offchannel);
> > -
> > /**
> > * rpmsg_set_flow_control() - request remote to pause/resume transmission
> > * @ept: the rpmsg endpoint
> > diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
> > index 90d8e4475f80..fb7ab9165645 100644
> > --- a/include/linux/rpmsg.h
> > +++ b/include/linux/rpmsg.h
> > @@ -184,13 +184,9 @@ struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *,
> >
> > int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len);
> > int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
> > -int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
> > - void *data, int len);
> >
> > int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len);
> > int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
> > -int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
> > - void *data, int len);
> >
> > __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
> > poll_table *wait);
> > @@ -271,15 +267,6 @@ static inline int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
> >
> > }
> >
> > -static inline int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src,
> > - u32 dst, void *data, int len)
> > -{
> > - /* This shouldn't be possible */
> > - WARN_ON(1);
> > -
> > - return -ENXIO;
> > -}
> > -
> > static inline int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
> > {
> > /* This shouldn't be possible */
> > @@ -297,15 +284,6 @@ static inline int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data,
> > return -ENXIO;
> > }
> >
> > -static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
> > - u32 dst, void *data, int len)
> > -{
> > - /* This shouldn't be possible */
> > - WARN_ON(1);
> > -
> > - return -ENXIO;
> > -}
> > -
> > static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept,
> > struct file *filp, poll_table *wait)
> > {
--
-----Open up your eyes, open up your mind, open up your code -------
/ Dr. David Alan Gilbert | Running GNU/Linux | Happy \
\ dave @ treblig.org | | In Hex /
\ _________________________|_____ http://www.treblig.org |_______/
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