| Message ID | 1375359046-17472-1-git-send-email-sebastian.hesselbarth@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
On Thu, Aug 01, 2013 at 02:10:46PM +0200, Sebastian Hesselbarth wrote: > i2c_put_adapter dereferences i2c_adapter pointer passed without check > for NULL. This adds a check for non-NULL pointer to allow i2c_put_adapter > called with NULL and behave the same way i2c_release_client does already. What about using WARN for the NULL case to point out the ref-counting imbalance? > > Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> > --- > Cc: Wolfram Sang <wsa@the-dreams.de> > Cc: linux-i2c@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/i2c/i2c-core.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index f32ca29..d075df6 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -1825,7 +1825,8 @@ EXPORT_SYMBOL(i2c_get_adapter); > > void i2c_put_adapter(struct i2c_adapter *adap) > { > - module_put(adap->owner); > + if (adap) > + module_put(adap->owner); > } > EXPORT_SYMBOL(i2c_put_adapter); > > -- > 1.7.10.4 >
On 08/05/13 11:00, Wolfram Sang wrote: > On Thu, Aug 01, 2013 at 02:10:46PM +0200, Sebastian Hesselbarth wrote: >> i2c_put_adapter dereferences i2c_adapter pointer passed without check >> for NULL. This adds a check for non-NULL pointer to allow i2c_put_adapter >> called with NULL and behave the same way i2c_release_client does already. > > What about using WARN for the NULL case to point out the ref-counting > imbalance? Wolfram, I was just adding this to (a) make it consistent with i2c_release_client and (b) it allows to simplify drivers where you need to release the adapter during probe failures. But that patch is so small, feel free to squash in anything you like. For a more sophisticated (WARN_ON) approach, I suggest to also put one into i2c_release_client then. Sebastian >> >> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> >> --- >> Cc: Wolfram Sang <wsa@the-dreams.de> >> Cc: linux-i2c@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> --- >> drivers/i2c/i2c-core.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c >> index f32ca29..d075df6 100644 >> --- a/drivers/i2c/i2c-core.c >> +++ b/drivers/i2c/i2c-core.c >> @@ -1825,7 +1825,8 @@ EXPORT_SYMBOL(i2c_get_adapter); >> >> void i2c_put_adapter(struct i2c_adapter *adap) >> { >> - module_put(adap->owner); >> + if (adap) >> + module_put(adap->owner); >> } >> EXPORT_SYMBOL(i2c_put_adapter); >> >> -- >> 1.7.10.4 >> -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Aug 05, 2013 at 11:31:42AM +0200, Sebastian Hesselbarth wrote: > On 08/05/13 11:00, Wolfram Sang wrote: > >On Thu, Aug 01, 2013 at 02:10:46PM +0200, Sebastian Hesselbarth wrote: > >>i2c_put_adapter dereferences i2c_adapter pointer passed without check > >>for NULL. This adds a check for non-NULL pointer to allow i2c_put_adapter > >>called with NULL and behave the same way i2c_release_client does already. > > > >What about using WARN for the NULL case to point out the ref-counting > >imbalance? > > Wolfram, > > I was just adding this to (a) make it consistent with i2c_release_client > and (b) it allows to simplify drivers where you need to release the > adapter during probe failures. But that patch is so small, feel free to > squash in anything you like. I am not forcing you to do this, I am calling for opinions here.
On Thu, Aug 01, 2013 at 02:10:46PM +0200, Sebastian Hesselbarth wrote: > i2c_put_adapter dereferences i2c_adapter pointer passed without check > for NULL. This adds a check for non-NULL pointer to allow i2c_put_adapter > called with NULL and behave the same way i2c_release_client does already. > > Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Applied to for-next, thanks! Please describe the use case next time in the patch description. The current text describes more what is changed not why. You did that later ("easier probing").
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index f32ca29..d075df6 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1825,7 +1825,8 @@ EXPORT_SYMBOL(i2c_get_adapter); void i2c_put_adapter(struct i2c_adapter *adap) { - module_put(adap->owner); + if (adap) + module_put(adap->owner); } EXPORT_SYMBOL(i2c_put_adapter);
i2c_put_adapter dereferences i2c_adapter pointer passed without check for NULL. This adds a check for non-NULL pointer to allow i2c_put_adapter called with NULL and behave the same way i2c_release_client does already. Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> --- Cc: Wolfram Sang <wsa@the-dreams.de> Cc: linux-i2c@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- drivers/i2c/i2c-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)