Hi Rajat,
On Fri, Jul 23, 2021 at 05:41:58PM -0700, Rajat Jain wrote:
> (fixing the typo in the email ID for Greg).
>
> On Fri, Jul 23, 2021 at 5:40 PM Rajat Jain <rajatja@xxxxxxxxxx> wrote:
> >
> > For security, we would like to monitor and track when the thunderbolt
> > devices are authorized and deauthorized (i.e. when the thunderbolt sysfs
> > "authorized" attribute changes). Currently the userspace gets a udev
> > change notification when there is a change, but the state may have
> > changed (again) by the time we look at the authorized attribute in
> > sysfs. So an authorization event may go unnoticed. Thus make it easier
> > by informing the actual change (new value of authorized attribute) in
> > the udev change notification.
> >
> > The change is included as a key value "authorized=<val>" where <val>
> > is the new value of sysfs attribute "authorized", and is described at
> > Documentation/ABI/testing/sysfs-bus-thunderbolt under
> > /sys/bus/thunderbolt/devices/.../authorized
Looking good, a couple of minor nits below.
> >
> > Signed-off-by: Rajat Jain <rajatja@xxxxxxxxxx>
> > ---
> > drivers/thunderbolt/switch.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
> > index 83b1ef3d5d03..382128dfbdee 100644
> > --- a/drivers/thunderbolt/switch.c
> > +++ b/drivers/thunderbolt/switch.c
> > @@ -1499,6 +1499,7 @@ static ssize_t authorized_show(struct device *dev,
> > static int disapprove_switch(struct device *dev, void *not_used)
> > {
> > struct tb_switch *sw;
> > + char *envp[] = { "AUTHORIZED=0", NULL };
Can you move arrange this to be before sw, like:
char *envp[] = { "AUTHORIZED=0", NULL };
struct tb_switch *sw;
> >
> > sw = tb_to_switch(dev);
> > if (sw && sw->authorized) {
> > @@ -1514,7 +1515,7 @@ static int disapprove_switch(struct device *dev, void *not_used)
> > return ret;
> >
> > sw->authorized = 0;
> > - kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);
> > + kobject_uevent_env(&sw->dev.kobj, KOBJ_CHANGE, envp);
> > }
> >
> > return 0;
> > @@ -1523,6 +1524,8 @@ static int disapprove_switch(struct device *dev, void *not_used)
> > static int tb_switch_set_authorized(struct tb_switch *sw, unsigned int val)
> > {
> > int ret = -EINVAL;
> > + char envp_string[13];
> > + char *envp[] = { envp_string, NULL };
Ditto.
> >
> > if (!mutex_trylock(&sw->tb->lock))
> > return restart_syscall();
> > @@ -1560,7 +1563,8 @@ static int tb_switch_set_authorized(struct tb_switch *sw, unsigned int val)
> > if (!ret) {
> > sw->authorized = val;
> > /* Notify status change to the userspace */
> > - kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);
> > + sprintf(envp_string, "AUTHORIZED=%u", sw->authorized);
> > + kobject_uevent_env(&sw->dev.kobj, KOBJ_CHANGE, envp);
> > }
> >
> > unlock:
> > --
> > 2.32.0.432.gabb21c7263-goog
> >
