| Message ID | 20220209045035.380615-2-tzungbi@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | platform/chrome: cros_ec: miscellaneous cleanups | expand |
Hi, On Tue, Feb 8, 2022 at 8:50 PM Tzung-Bi Shih <tzungbi@google.com> wrote: > > Fix cros_ec_register() doesn't unregister platform devices if > blocking_notifier_chain_register() fails. This isn't grammatically correct. Instead: Fix cros_ec_register() to unregister platform devices if blocking.... > > Also use the single exit path to handle the platform device > unregistration. > > This fix depends on the fact that all the callers of cros_ec_register() > allocate zeroed memory. Is that a fair assumption? What happens if a future driver calls cros_ec_register() without zeroed memory? > > Fixes: 42cd0ab476e2 ("platform/chrome: cros_ec: Query EC protocol version if EC transitions between RO/RW") > Signed-off-by: Tzung-Bi Shih <tzungbi@google.com> > --- What has changed since v2? Please add a change log of the versions here. > drivers/platform/chrome/cros_ec.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c > index fc5aa1525d13..7ce667ff08e0 100644 > --- a/drivers/platform/chrome/cros_ec.c > +++ b/drivers/platform/chrome/cros_ec.c > @@ -245,18 +245,16 @@ int cros_ec_register(struct cros_ec_device *ec_dev) > if (IS_ERR(ec_dev->pd)) { > dev_err(ec_dev->dev, > "Failed to create CrOS PD platform device\n"); > - platform_device_unregister(ec_dev->ec); > - return PTR_ERR(ec_dev->pd); > + err = PTR_ERR(ec_dev->pd); > + goto exit; > } > } > > if (IS_ENABLED(CONFIG_OF) && dev->of_node) { > err = devm_of_platform_populate(dev); > if (err) { > - platform_device_unregister(ec_dev->pd); > - platform_device_unregister(ec_dev->ec); > dev_err(dev, "Failed to register sub-devices\n"); > - return err; > + goto exit; > } > } > > @@ -278,7 +276,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev) > err = blocking_notifier_chain_register(&ec_dev->event_notifier, > &ec_dev->notifier_ready); > if (err) > - return err; > + goto exit; > } > > dev_info(dev, "Chrome EC device registered\n"); > @@ -291,6 +289,12 @@ int cros_ec_register(struct cros_ec_device *ec_dev) > cros_ec_irq_thread(0, ec_dev); > > return 0; > +exit: > + if (!IS_ERR_OR_NULL(ec_dev->pd)) > + platform_device_unregister(ec_dev->pd); > + if (!IS_ERR_OR_NULL(ec_dev->ec)) > + platform_device_unregister(ec_dev->ec); > + return err; You don't need these "if" checks. They are already performed by platform_device_unregister(), or rather, the functions that it calls [1][2]. [1] https://elixir.bootlin.com/linux/latest/source/drivers/base/platform.c#L756 [2] https://elixir.bootlin.com/linux/latest/source/drivers/base/platform.c#L553
On Tue, Feb 08, 2022 at 09:38:55PM -0800, Prashant Malani wrote: > On Tue, Feb 8, 2022 at 8:50 PM Tzung-Bi Shih <tzungbi@google.com> wrote: > > > > Fix cros_ec_register() doesn't unregister platform devices if > > blocking_notifier_chain_register() fails. > > This isn't grammatically correct. Instead: > Fix cros_ec_register() to unregister platform devices if blocking.... Thanks, will fix in next version. > > Also use the single exit path to handle the platform device > > unregistration. > > > > This fix depends on the fact that all the callers of cros_ec_register() > > allocate zeroed memory. > > Is that a fair assumption? What happens if a future driver calls > cros_ec_register() > without zeroed memory? Suppose ec_dev->pd is garbage data, platform_device_unregister() will operate on invalid memory address. Let's use another guard condition in next version instead of relying on zeroed memory. > > --- > What has changed since v2? Please add a change log of the versions here. They are in the cover letter actually. Will copy them to each patch. > > @@ -291,6 +289,12 @@ int cros_ec_register(struct cros_ec_device *ec_dev) > > cros_ec_irq_thread(0, ec_dev); > > > > return 0; > > +exit: > > + if (!IS_ERR_OR_NULL(ec_dev->pd)) > > + platform_device_unregister(ec_dev->pd); > > + if (!IS_ERR_OR_NULL(ec_dev->ec)) > > + platform_device_unregister(ec_dev->ec); > > + return err; > You don't need these "if" checks. They are already performed by > platform_device_unregister(), or rather, the functions that it calls [1][2]. Ack, will remove the check in next version.
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c index fc5aa1525d13..7ce667ff08e0 100644 --- a/drivers/platform/chrome/cros_ec.c +++ b/drivers/platform/chrome/cros_ec.c @@ -245,18 +245,16 @@ int cros_ec_register(struct cros_ec_device *ec_dev) if (IS_ERR(ec_dev->pd)) { dev_err(ec_dev->dev, "Failed to create CrOS PD platform device\n"); - platform_device_unregister(ec_dev->ec); - return PTR_ERR(ec_dev->pd); + err = PTR_ERR(ec_dev->pd); + goto exit; } } if (IS_ENABLED(CONFIG_OF) && dev->of_node) { err = devm_of_platform_populate(dev); if (err) { - platform_device_unregister(ec_dev->pd); - platform_device_unregister(ec_dev->ec); dev_err(dev, "Failed to register sub-devices\n"); - return err; + goto exit; } } @@ -278,7 +276,7 @@ int cros_ec_register(struct cros_ec_device *ec_dev) err = blocking_notifier_chain_register(&ec_dev->event_notifier, &ec_dev->notifier_ready); if (err) - return err; + goto exit; } dev_info(dev, "Chrome EC device registered\n"); @@ -291,6 +289,12 @@ int cros_ec_register(struct cros_ec_device *ec_dev) cros_ec_irq_thread(0, ec_dev); return 0; +exit: + if (!IS_ERR_OR_NULL(ec_dev->pd)) + platform_device_unregister(ec_dev->pd); + if (!IS_ERR_OR_NULL(ec_dev->ec)) + platform_device_unregister(ec_dev->ec); + return err; } EXPORT_SYMBOL(cros_ec_register);
Fix cros_ec_register() doesn't unregister platform devices if blocking_notifier_chain_register() fails. Also use the single exit path to handle the platform device unregistration. This fix depends on the fact that all the callers of cros_ec_register() allocate zeroed memory. Fixes: 42cd0ab476e2 ("platform/chrome: cros_ec: Query EC protocol version if EC transitions between RO/RW") Signed-off-by: Tzung-Bi Shih <tzungbi@google.com> --- drivers/platform/chrome/cros_ec.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)