linux-kernel - Re: [PATCH v4 2/3] remoteproc: xlnx: assign mbox client per mbox channel

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CABb+yY12vSxs=TA42ybkFUUhdbXyxkGoFMBfk01xm-Tb+g6q1Q@mail.gmail.com>
Date: Mon, 9 Feb 2026 17:27:31 -0600
From: Jassi Brar <jassisinghbrar@...il.com>
To: Tanmay Shah <tanmay.shah@....com>
Cc: andersson@...nel.org, mathieu.poirier@...aro.org, 
	linux-kernel@...r.kernel.org, linux-remoteproc@...r.kernel.org
Subject: Re: [PATCH v4 2/3] remoteproc: xlnx: assign mbox client per mbox channel

On Tue, Feb 3, 2026 at 4:59 PM Tanmay Shah <tanmay.shah@....com> wrote:
>
> Sharing mbox client data structure between "tx" and "rx" channels
> can lead to data corruption. Instead each channel should have its own
> mbox client data structure.
>
> Signed-off-by: Tanmay Shah <tanmay.shah@....com>
> ---
>
> changes in v4:
>   - separate remoteproc driver patch in to two patches
>
>  drivers/remoteproc/xlnx_r5_remoteproc.c | 19 ++++++++++++++-----
>  1 file changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
> index bd619a6c42aa..109831c5815c 100644
> --- a/drivers/remoteproc/xlnx_r5_remoteproc.c
> +++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
> @@ -74,7 +74,8 @@ struct zynqmp_sram_bank {
>   * @tx_mc_buf: to copy data to mailbox tx channel
>   * @r5_core: this mailbox's corresponding r5_core pointer
>   * @mbox_work: schedule work after receiving data from mailbox
> - * @mbox_cl: mailbox client
> + * @mbox_tx_cl: tx channel mailbox client
> + * @mbox_rx_cl: rx channel mailbox client
>   * @tx_chan: mailbox tx channel
>   * @rx_chan: mailbox rx channel
>   */
> @@ -83,7 +84,8 @@ struct mbox_info {
>         unsigned char tx_mc_buf[MBOX_CLIENT_BUF_MAX];
>         struct zynqmp_r5_core *r5_core;
>         struct work_struct mbox_work;
> -       struct mbox_client mbox_cl;
> +       struct mbox_client mbox_tx_cl;
> +       struct mbox_client mbox_rx_cl;
>         struct mbox_chan *tx_chan;
>         struct mbox_chan *rx_chan;
>  };
> @@ -230,7 +232,7 @@ static void zynqmp_r5_mb_rx_cb(struct mbox_client *cl, void *msg)
>         struct mbox_info *ipi;
>         size_t len;
>
> -       ipi = container_of(cl, struct mbox_info, mbox_cl);
> +       ipi = container_of(cl, struct mbox_info, mbox_rx_cl);
>
>         /* copy data from ipi buffer to r5_core */
>         ipi_msg = (struct zynqmp_ipi_message *)msg;
> @@ -269,8 +271,8 @@ static struct mbox_info *zynqmp_r5_setup_mbox(struct device *cdev)
>         if (!ipi)
>                 return NULL;
>
> -       mbox_cl = &ipi->mbox_cl;
> -       mbox_cl->rx_callback = zynqmp_r5_mb_rx_cb;
> +       mbox_cl = &ipi->mbox_tx_cl;
> +       mbox_cl->rx_callback = NULL;
>         mbox_cl->tx_block = false;
>         mbox_cl->knows_txdone = false;
>         mbox_cl->tx_done = NULL;
> @@ -285,6 +287,13 @@ static struct mbox_info *zynqmp_r5_setup_mbox(struct device *cdev)
>                 return NULL;
>         }
>
> +       mbox_cl = &ipi->mbox_rx_cl;
> +       mbox_cl->rx_callback = zynqmp_r5_mb_rx_cb;
> +       mbox_cl->tx_block = false;
> +       mbox_cl->knows_txdone = false;
> +       mbox_cl->tx_done = NULL;
> +       mbox_cl->dev = cdev;
> +
hmm... this looks bad. Sorry.
I think all we need is to export
  unsigned int mbox_chan_tx_slots_available(struct mbox_chan *chan) {
return MBOX_TX_QUEUE_LEN - chan->msg_count}
from mailbox.c, of course with protection of the channel lock.
That should work for you, right?

Regards,
Jassi