| Message ID | 20210218191723.20030-1-mario.limonciello@dell.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | platform/x86: dell-wmi-sysman: correct an initialization failure | expand |
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 <Divya_Bharathi@Dell.com> > Reported-by: Alexander Naumann <alexandernaumann@gmx.de> > Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> > --- > 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 <mgross@linux.intel.com> > Sent: Thursday, February 18, 2021 16:49 > To: Limonciello, Mario > Cc: Hans De Goede; Mark Gross; LKML; platform-driver-x86@vger.kernel.org; > 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 <Divya_Bharathi@Dell.com> > > Reported-by: Alexander Naumann <alexandernaumann@gmx.de> > > Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> > > --- > > 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 <mgross@linux.intel.com> >> Sent: Thursday, February 18, 2021 16:49 >> To: Limonciello, Mario >> Cc: Hans De Goede; Mark Gross; LKML; platform-driver-x86@vger.kernel.org; >> 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 <Divya_Bharathi@Dell.com> >>> Reported-by: Alexander Naumann <alexandernaumann@gmx.de> >>> Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> >>> --- >>> 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
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; }
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 <Divya_Bharathi@Dell.com> Reported-by: Alexander Naumann <alexandernaumann@gmx.de> Signed-off-by: Mario Limonciello <mario.limonciello@dell.com> --- 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(-)