On Dell systems that don't support this interface the module is
mistakingly returning error code "0", when it should be returning
-ENODEV. Correct a logic error to guarantee the correct return code.
Cc: Divya Bharathi <[email protected]>
Reported-by: Alexander Naumann <[email protected]>
Signed-off-by: Mario Limonciello <[email protected]>
---
drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c | 4 +++-
drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c | 4 +++-
drivers/platform/x86/dell-wmi-sysman/sysman.c | 4 ++--
3 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
index f95d8ddace5a..8d59f81f9db4 100644
--- a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
+++ b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
@@ -175,7 +175,9 @@ static struct wmi_driver bios_attr_set_interface_driver = {
int init_bios_attr_set_interface(void)
{
- return wmi_driver_register(&bios_attr_set_interface_driver);
+ int ret = wmi_driver_register(&bios_attr_set_interface_driver);
+
+ return wmi_priv.bios_attr_wdev ? ret : -ENODEV;
}
void exit_bios_attr_set_interface(void)
diff --git a/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c b/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
index 5780b4d94759..bf449dc5ff47 100644
--- a/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
+++ b/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
@@ -142,7 +142,9 @@ static struct wmi_driver bios_attr_pass_interface_driver = {
int init_bios_attr_pass_interface(void)
{
- return wmi_driver_register(&bios_attr_pass_interface_driver);
+ int ret = wmi_driver_register(&bios_attr_pass_interface_driver);
+
+ return wmi_priv.password_attr_wdev ? ret : -ENODEV;
}
void exit_bios_attr_pass_interface(void)
diff --git a/drivers/platform/x86/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell-wmi-sysman/sysman.c
index cb81010ba1a2..d9ad0e83b66f 100644
--- a/drivers/platform/x86/dell-wmi-sysman/sysman.c
+++ b/drivers/platform/x86/dell-wmi-sysman/sysman.c
@@ -513,13 +513,13 @@ static int __init sysman_init(void)
}
ret = init_bios_attr_set_interface();
- if (ret || !wmi_priv.bios_attr_wdev) {
+ if (ret) {
pr_debug("failed to initialize set interface\n");
goto fail_set_interface;
}
ret = init_bios_attr_pass_interface();
- if (ret || !wmi_priv.password_attr_wdev) {
+ if (ret) {
pr_debug("failed to initialize pass interface\n");
goto fail_pass_interface;
}
--
2.25.1
On Thu, Feb 18, 2021 at 01:17:23PM -0600, Mario Limonciello wrote:
> On Dell systems that don't support this interface the module is
> mistakingly returning error code "0", when it should be returning
> -ENODEV. Correct a logic error to guarantee the correct return code.
>
> Cc: Divya Bharathi <[email protected]>
> Reported-by: Alexander Naumann <[email protected]>
> Signed-off-by: Mario Limonciello <[email protected]>
> ---
> drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c | 4 +++-
> drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c | 4 +++-
> drivers/platform/x86/dell-wmi-sysman/sysman.c | 4 ++--
> 3 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> index f95d8ddace5a..8d59f81f9db4 100644
> --- a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> +++ b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> @@ -175,7 +175,9 @@ static struct wmi_driver bios_attr_set_interface_driver = {
>
> int init_bios_attr_set_interface(void)
> {
> - return wmi_driver_register(&bios_attr_set_interface_driver);
> + int ret = wmi_driver_register(&bios_attr_set_interface_driver);
I have to ask if the propper fix should be in wmi_driver_register
> +
> + return wmi_priv.bios_attr_wdev ? ret : -ENODEV;
Also, is there any point to call wmi_driver_register if returning -ENODEV?
i.e. should the call to driver register be wrapped in a test for
bios_atter_wdev?
> }
>
> void exit_bios_attr_set_interface(void)
> diff --git a/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c b/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> index 5780b4d94759..bf449dc5ff47 100644
> --- a/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> +++ b/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> @@ -142,7 +142,9 @@ static struct wmi_driver bios_attr_pass_interface_driver = {
>
> int init_bios_attr_pass_interface(void)
> {
> - return wmi_driver_register(&bios_attr_pass_interface_driver);
> + int ret = wmi_driver_register(&bios_attr_pass_interface_driver);
> +
> + return wmi_priv.password_attr_wdev ? ret : -ENODEV;
same comments as above only for password_atter_wdev.
--mark
> }
>
> void exit_bios_attr_pass_interface(void)
> diff --git a/drivers/platform/x86/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell-wmi-sysman/sysman.c
> index cb81010ba1a2..d9ad0e83b66f 100644
> --- a/drivers/platform/x86/dell-wmi-sysman/sysman.c
> +++ b/drivers/platform/x86/dell-wmi-sysman/sysman.c
> @@ -513,13 +513,13 @@ static int __init sysman_init(void)
> }
>
> ret = init_bios_attr_set_interface();
> - if (ret || !wmi_priv.bios_attr_wdev) {
> + if (ret) {
> pr_debug("failed to initialize set interface\n");
> goto fail_set_interface;
> }
>
> ret = init_bios_attr_pass_interface();
> - if (ret || !wmi_priv.password_attr_wdev) {
> + if (ret) {
> pr_debug("failed to initialize pass interface\n");
> goto fail_pass_interface;
> }
> --
> 2.25.1
>
> -----Original Message-----
> From: mark gross <[email protected]>
> Sent: Thursday, February 18, 2021 16:49
> To: Limonciello, Mario
> Cc: Hans De Goede; Mark Gross; LKML; [email protected];
> Bharathi, Divya; Alexander Naumann
> Subject: Re: [PATCH] platform/x86: dell-wmi-sysman: correct an initialization
> failure
>
>
> [EXTERNAL EMAIL]
>
> On Thu, Feb 18, 2021 at 01:17:23PM -0600, Mario Limonciello wrote:
> > On Dell systems that don't support this interface the module is
> > mistakingly returning error code "0", when it should be returning
> > -ENODEV. Correct a logic error to guarantee the correct return code.
> >
> > Cc: Divya Bharathi <[email protected]>
> > Reported-by: Alexander Naumann <[email protected]>
> > Signed-off-by: Mario Limonciello <[email protected]>
> > ---
> > drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c | 4 +++-
> > drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c | 4 +++-
> > drivers/platform/x86/dell-wmi-sysman/sysman.c | 4 ++--
> > 3 files changed, 8 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> > index f95d8ddace5a..8d59f81f9db4 100644
> > --- a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> > +++ b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
> > @@ -175,7 +175,9 @@ static struct wmi_driver bios_attr_set_interface_driver
> = {
> >
> > int init_bios_attr_set_interface(void)
> > {
> > - return wmi_driver_register(&bios_attr_set_interface_driver);
> > + int ret = wmi_driver_register(&bios_attr_set_interface_driver);
> I have to ask if the propper fix should be in wmi_driver_register
Do you mean something like this?
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index c669676ea8e8..89d04c5e3ab9 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -1415,6 +1415,11 @@ static int acpi_wmi_probe(struct platform_device *device)
int __must_check __wmi_driver_register(struct wmi_driver *driver,
struct module *owner)
{
+ const struct wmi_device_id *id = driver->id_table;
+
+ if (!wmi_has_guid(id->guid_string))
+ return -ENODEV;
+
driver->driver.owner = owner;
driver->driver.bus = &wmi_bus_type;
> > +
> > + return wmi_priv.bios_attr_wdev ? ret : -ENODEV;
> Also, is there any point to call wmi_driver_register if returning -ENODEV?
> i.e. should the call to driver register be wrapped in a test for
> bios_atter_wdev?
With some bus types it probably makes sense to register the driver whether or
not the device is present. With the wmi bus it's fixed at bootup.
>
>
> > }
> >
> > void exit_bios_attr_set_interface(void)
> > diff --git a/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> b/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> > index 5780b4d94759..bf449dc5ff47 100644
> > --- a/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> > +++ b/drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c
> > @@ -142,7 +142,9 @@ static struct wmi_driver bios_attr_pass_interface_driver
> = {
> >
> > int init_bios_attr_pass_interface(void)
> > {
> > - return wmi_driver_register(&bios_attr_pass_interface_driver);
> > + int ret = wmi_driver_register(&bios_attr_pass_interface_driver);
> > +
> > + return wmi_priv.password_attr_wdev ? ret : -ENODEV;
> same comments as above only for password_atter_wdev.
>
> --mark
>
> > }
> >
> > void exit_bios_attr_pass_interface(void)
> > diff --git a/drivers/platform/x86/dell-wmi-sysman/sysman.c
> b/drivers/platform/x86/dell-wmi-sysman/sysman.c
> > index cb81010ba1a2..d9ad0e83b66f 100644
> > --- a/drivers/platform/x86/dell-wmi-sysman/sysman.c
> > +++ b/drivers/platform/x86/dell-wmi-sysman/sysman.c
> > @@ -513,13 +513,13 @@ static int __init sysman_init(void)
> > }
> >
> > ret = init_bios_attr_set_interface();
> > - if (ret || !wmi_priv.bios_attr_wdev) {
> > + if (ret) {
> > pr_debug("failed to initialize set interface\n");
> > goto fail_set_interface;
> > }
> >
> > ret = init_bios_attr_pass_interface();
> > - if (ret || !wmi_priv.password_attr_wdev) {
> > + if (ret) {
> > pr_debug("failed to initialize pass interface\n");
> > goto fail_pass_interface;
> > }
> > --
> > 2.25.1
> >
Hi,
On 2/19/21 12:26 AM, Limonciello, Mario wrote:
>
>
>> -----Original Message-----
>> From: mark gross <[email protected]>
>> Sent: Thursday, February 18, 2021 16:49
>> To: Limonciello, Mario
>> Cc: Hans De Goede; Mark Gross; LKML; [email protected];
>> Bharathi, Divya; Alexander Naumann
>> Subject: Re: [PATCH] platform/x86: dell-wmi-sysman: correct an initialization
>> failure
>>
>>
>> [EXTERNAL EMAIL]
>>
>> On Thu, Feb 18, 2021 at 01:17:23PM -0600, Mario Limonciello wrote:
>>> On Dell systems that don't support this interface the module is
>>> mistakingly returning error code "0", when it should be returning
>>> -ENODEV. Correct a logic error to guarantee the correct return code.
>>>
>>> Cc: Divya Bharathi <[email protected]>
>>> Reported-by: Alexander Naumann <[email protected]>
>>> Signed-off-by: Mario Limonciello <[email protected]>
>>> ---
>>> drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c | 4 +++-
>>> drivers/platform/x86/dell-wmi-sysman/passwordattr-interface.c | 4 +++-
>>> drivers/platform/x86/dell-wmi-sysman/sysman.c | 4 ++--
>>> 3 files changed, 8 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
>> b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
>>> index f95d8ddace5a..8d59f81f9db4 100644
>>> --- a/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
>>> +++ b/drivers/platform/x86/dell-wmi-sysman/biosattr-interface.c
>>> @@ -175,7 +175,9 @@ static struct wmi_driver bios_attr_set_interface_driver
>> = {
>>>
>>> int init_bios_attr_set_interface(void)
>>> {
>>> - return wmi_driver_register(&bios_attr_set_interface_driver);
>>> + int ret = wmi_driver_register(&bios_attr_set_interface_driver);
>> I have to ask if the propper fix should be in wmi_driver_register
>
> Do you mean something like this?
>
> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
> index c669676ea8e8..89d04c5e3ab9 100644
> --- a/drivers/platform/x86/wmi.c
> +++ b/drivers/platform/x86/wmi.c
> @@ -1415,6 +1415,11 @@ static int acpi_wmi_probe(struct platform_device *device)
> int __must_check __wmi_driver_register(struct wmi_driver *driver,
> struct module *owner)
> {
> + const struct wmi_device_id *id = driver->id_table;
> +
> + if (!wmi_has_guid(id->guid_string))
> + return -ENODEV;
> +
> driver->driver.owner = owner;
> driver->driver.bus = &wmi_bus_type;
>
No, drivers should be able to register before the GUID shows up. I know that
the GUID showing up later will likely never happen with WMI, but having a match
check like this in the driver_register function is highly unusual and would
be different from what all other busses do.
But your initial fix here is wrong too, because it does call wmi_driver_register,
which succeeds and then makes sysman_init() exit with -ENODEV.
Returning -ENODEV from sysman_init() is what we want, this causes the entire
insmod to be aborted, without logging an error (because of -ENODEV) so the
code will not be taking up memory.
This means that the memory into which the module was loaded before the kernel
calls sysman_init() will be free-ed and now the *still* registered WMI driver
entry will point to that free-ed memory, which is not good (TM).
So instead init_bios_attr_set_interface() should become something like this:
int init_bios_attr_set_interface(void)
{
int ret;
ret = wmi_driver_register(&bios_attr_set_interface_driver);
if (ret)
return ret;
if (!wmi_priv.bios_attr_wdev) {
wmi_driver_unregister(&bios_attr_set_interface_driver);
return -ENODEV;
}
return 0;
}
And the same for the init_bios_attr_pass_interface() function.
This follows the standard kernel pattern that a function should always
undo any things / resource-allocations it has done on error before
exiting with an error.
Regards,
Hans