Messages in this thread |  | | Date | Wed, 3 Oct 2018 17:54:33 -0700 | From | Bjorn Andersson <> | Subject | Re: [PATCH 3/5] rpmsg: Add TIOCMGET/TIOCMSET ioctl support |
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On Wed 03 Oct 04:34 PDT 2018, Arun Kumar Neelakantam wrote:
> Add TICOMGET and TIOCMSET ioctl support for rpmsg char device nodes > to get/set the low level transport signals. > > Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org> > --- > drivers/rpmsg/rpmsg_char.c | 54 +++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 51 insertions(+), 3 deletions(-) > > diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c > index 86003d5..c983d6c 100644 > --- a/drivers/rpmsg/rpmsg_char.c > +++ b/drivers/rpmsg/rpmsg_char.c > @@ -20,6 +20,7 @@ > #include <linux/rpmsg.h> > #include <linux/skbuff.h> > #include <linux/slab.h> > +#include <linux/termios.h> > #include <linux/uaccess.h> > #include <uapi/linux/rpmsg.h> > > @@ -274,15 +275,62 @@ static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) > return mask; > } > > +static int rpmsg_eptdev_tiocmset(struct file *fp, unsigned int cmd, > + unsigned long arg)
Make arg type int __user *
> +{ > + struct rpmsg_eptdev *eptdev = fp->private_data; > + u32 lsigs, rsigs, val; > + int ret; > + > + ret = get_user(val, (u32 *)arg); > + if (ret) > + return ret; > + > + ret = rpmsg_get_sigs(eptdev->ept, &lsigs, &rsigs); > + if (ret < 0) > + return ret; > + > + switch (cmd) { > + case TIOCMBIS: > + lsigs |= val; > + break; > + case TIOCMBIC: > + lsigs &= ~val; > + break; > + case TIOCMSET: > + lsigs = val; > + break; > + } > + > + ret = rpmsg_set_sigs(eptdev->ept, lsigs);
This is racy, as the signals might change while we update them. Mimic tty_tiocmset() instead and make rpmsg_set_sigs() take a clear and set mask.
And please do spell out rpmsg_set_signal() and rpmsg_get_signal().
> + return ret;
return rpmsg_set_signals();
> +} > + > static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd, > unsigned long arg) > { > struct rpmsg_eptdev *eptdev = fp->private_data; > + u32 lsigs, rsigs; > + int ret; > > - if (cmd != RPMSG_DESTROY_EPT_IOCTL) > - return -EINVAL; > + switch (cmd) { > + case TIOCMGET: > + ret = rpmsg_get_sigs(eptdev->ept, &lsigs, &rsigs); > + if (!ret) > + ret = put_user(rsigs, (u32 *)arg);
Cast to int __user *
> + break; > + case TIOCMSET: > + case TIOCMBIS: > + case TIOCMBIC: > + ret = rpmsg_eptdev_tiocmset(fp, cmd, arg); > + break; > + case RPMSG_DESTROY_EPT_IOCTL: > + ret = rpmsg_eptdev_destroy(&eptdev->dev, NULL); > + default: > + ret = -EINVAL; > + } > > - return rpmsg_eptdev_destroy(&eptdev->dev, NULL); > + return ret; > }
Regards, Bjorn
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