| Message ID | 20190325173722.49414-1-steven.price@arm.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Commit | fa7fe29a645b4da08efe8ff2392898b88f9ded9f |
| Headers | show |
| Series | firmware: arm_scmi: Fix leak in scmi_mailbox_check | expand |
On 3/25/2019 11:07 PM, Steven Price wrote: > of_parse_phandle_with_args() requires the caller to call of_node_put() on > the returned args->np pointer. Otherwise the reference count will remain > incremented. > > However, in this case, since we don't actually use the returned pointer, > we can simply pass in NULL. > > Fixes: aa4f886f3893f ("firmware: arm_scmi: add basic driver infrastructure for SCMI") > Signed-off-by: Steven Price <steven.price@arm.com> > --- > drivers/firmware/arm_scmi/driver.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 8f952f2f1a29..dd967d675c08 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -654,9 +654,7 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo) > > static int scmi_mailbox_check(struct device_node *np) > { > - struct of_phandle_args arg; > - > - return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, &arg); > + return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, NULL); Although, it is not used but it is better to put arg->np instead of passing NULL. Here, you are making the driver not to fill arguement which is customised solution, that may change in future. Thanks. Mukesh > } > > static int scmi_mbox_free_channel(int id, void *p, void *data)
On 26/03/2019 07:23, Mukesh Ojha wrote: > > On 3/25/2019 11:07 PM, Steven Price wrote: >> of_parse_phandle_with_args() requires the caller to call of_node_put() on >> the returned args->np pointer. Otherwise the reference count will remain >> incremented. >> >> However, in this case, since we don't actually use the returned pointer, >> we can simply pass in NULL. >> >> Fixes: aa4f886f3893f ("firmware: arm_scmi: add basic driver >> infrastructure for SCMI") >> Signed-off-by: Steven Price <steven.price@arm.com> >> --- >> drivers/firmware/arm_scmi/driver.c | 4 +--- >> 1 file changed, 1 insertion(+), 3 deletions(-) >> >> diff --git a/drivers/firmware/arm_scmi/driver.c >> b/drivers/firmware/arm_scmi/driver.c >> index 8f952f2f1a29..dd967d675c08 100644 >> --- a/drivers/firmware/arm_scmi/driver.c >> +++ b/drivers/firmware/arm_scmi/driver.c >> @@ -654,9 +654,7 @@ static int scmi_xfer_info_init(struct scmi_info >> *sinfo) >> static int scmi_mailbox_check(struct device_node *np) >> { >> - struct of_phandle_args arg; >> - >> - return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, >> &arg); >> + return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, >> NULL); > > Although, it is not used but it is better to put arg->np instead of > passing NULL. > Here, you are making the driver not to fill arguement which is > customised solution, that may change in future. The function of_parse_phandle_with_args() is documented thus: > * of_parse_phandle_with_args() - Find a node pointed by phandle in a list > * @np: pointer to a device tree node containing a list > * @list_name: property name that contains a list > * @cells_name: property name that specifies phandles' arguments count > * @index: index of a phandle to parse out > * @out_args: optional pointer to output arguments structure (will be filled) So I'm going by the documentation (and implementation) which both consider out_args to be optional. The alternative is of course: > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c > index 8f952f2f1a29..aa6c0728e676 100644 > --- a/drivers/firmware/arm_scmi/driver.c > +++ b/drivers/firmware/arm_scmi/driver.c > @@ -655,8 +655,11 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo) > static int scmi_mailbox_check(struct device_node *np) > { > struct of_phandle_args arg; > + int ret; > > - return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, &arg); > + ret = of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, &arg); > + of_node_put(arg->np); > + return ret; > } > > static int scmi_mbox_free_channel(int id, void *p, void *data) But personally that doesn't seem as good. Is there any reason to think the interface of of_parse_phandle_with_args() will change? Steve
On Mon, Mar 25, 2019 at 05:37:22PM +0000, Steven Price wrote: > of_parse_phandle_with_args() requires the caller to call of_node_put() on > the returned args->np pointer. Otherwise the reference count will remain > incremented. > Good find and thanks for the fix. > However, in this case, since we don't actually use the returned pointer, > we can simply pass in NULL. > > Fixes: aa4f886f3893f ("firmware: arm_scmi: add basic driver infrastructure for SCMI") > Signed-off-by: Steven Price <steven.price@arm.com> Applied. -- Regards, Sudeep
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 8f952f2f1a29..dd967d675c08 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -654,9 +654,7 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo) static int scmi_mailbox_check(struct device_node *np) { - struct of_phandle_args arg; - - return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, &arg); + return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells", 0, NULL); } static int scmi_mbox_free_channel(int id, void *p, void *data)
of_parse_phandle_with_args() requires the caller to call of_node_put() on the returned args->np pointer. Otherwise the reference count will remain incremented. However, in this case, since we don't actually use the returned pointer, we can simply pass in NULL. Fixes: aa4f886f3893f ("firmware: arm_scmi: add basic driver infrastructure for SCMI") Signed-off-by: Steven Price <steven.price@arm.com> --- drivers/firmware/arm_scmi/driver.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)