* Re: [PATCH] ipmi: Don't allow device module unload when in use
2019-10-14 15:46 ` [PATCH] ipmi: Don't allow device module unload when in use minyard
@ 2019-10-16 12:18 ` tony camuso
2019-10-16 13:13 ` tony camuso
2019-10-16 19:25 ` Tony Camuso
2019-10-22 14:29 ` Tony Camuso
2 siblings, 1 reply; 8+ messages in thread
From: tony camuso @ 2019-10-16 12:18 UTC (permalink / raw)
To: minyard; +Cc: openipmi-developer, linux-kernel, Corey Minyard
On 10/14/19 11:46 AM, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
>
> If something has the IPMI driver open, don't allow the device
> module to be unloaded. Before it would unload and the user would
> get errors on use.
>
> This change is made on user request, and it makes it consistent
> with the I2C driver, which has the same behavior.
>
> It does change things a little bit with respect to kernel users.
> If the ACPI or IPMI watchdog (or any other kernel user) has
> created a user, then the device module cannot be unloaded. Before
> it could be unloaded,
>
> This does not affect hot-plug. If the device goes away (it's on
> something removable that is removed or is hot-removed via sysfs)
> then it still behaves as it did before.
>
> Reported-by: tony camuso <tcamuso@redhat.com>
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> ---
> Tony, here is a suggested change for this. Can you look it over and
> see if it looks ok?
>
> Thanks,
>
> -corey
>
> drivers/char/ipmi/ipmi_msghandler.c | 23 ++++++++++++++++-------
> include/linux/ipmi_smi.h | 12 ++++++++----
> 2 files changed, 24 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index 2aab80e19ae0..15680de18625 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -448,6 +448,8 @@ enum ipmi_stat_indexes {
>
> #define IPMI_IPMB_NUM_SEQ 64
> struct ipmi_smi {
> + struct module *owner;
> +
> /* What interface number are we? */
> int intf_num;
>
> @@ -1220,6 +1222,11 @@ int ipmi_create_user(unsigned int if_num,
> if (rv)
> goto out_kfree;
>
> + if (!try_module_get(intf->owner)) {
> + rv = -ENODEV;
> + goto out_kfree;
> + }
> +
> /* Note that each existing user holds a refcount to the interface. */
> kref_get(&intf->refcount);
>
> @@ -1349,6 +1356,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
> }
>
> kref_put(&intf->refcount, intf_free);
> + module_put(intf->owner);
> }
>
> int ipmi_destroy_user(struct ipmi_user *user)
> @@ -2459,7 +2467,7 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
> * been recently fetched, this will just use the cached data. Otherwise
> * it will run a new fetch.
> *
> - * Except for the first time this is called (in ipmi_register_smi()),
> + * Except for the first time this is called (in ipmi_add_smi()),
> * this will always return good data;
> */
> static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
> @@ -3377,10 +3385,11 @@ static void redo_bmc_reg(struct work_struct *work)
> kref_put(&intf->refcount, intf_free);
> }
>
> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> - void *send_info,
> - struct device *si_dev,
> - unsigned char slave_addr)
> +int ipmi_add_smi(struct module *owner,
> + const struct ipmi_smi_handlers *handlers,
> + void *send_info,
> + struct device *si_dev,
> + unsigned char slave_addr)
> {
> int i, j;
> int rv;
> @@ -3406,7 +3415,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> return rv;
> }
>
> -
> + intf->owner = owner;
> intf->bmc = &intf->tmp_bmc;
> INIT_LIST_HEAD(&intf->bmc->intfs);
> mutex_init(&intf->bmc->dyn_mutex);
> @@ -3514,7 +3523,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>
> return rv;
> }
> -EXPORT_SYMBOL(ipmi_register_smi);
> +EXPORT_SYMBOL(ipmi_add_smi);
>
> static void deliver_smi_err_response(struct ipmi_smi *intf,
> struct ipmi_smi_msg *msg,
> diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
> index 4dc66157d872..deec18b8944a 100644
> --- a/include/linux/ipmi_smi.h
> +++ b/include/linux/ipmi_smi.h
> @@ -224,10 +224,14 @@ static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd,
> * is called, and the lower layer must get the interface from that
> * call.
> */
> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> - void *send_info,
> - struct device *dev,
> - unsigned char slave_addr);
> +int ipmi_add_smi(struct module *owner,
> + const struct ipmi_smi_handlers *handlers,
> + void *send_info,
> + struct device *dev,
> + unsigned char slave_addr);
> +
> +#define ipmi_register_smi(handlers, send_info, dev, slave_addr) \
> + ipmi_add_smi(THIS_MODULE, handlers, send_info, dev, slave_addr)
>
> /*
> * Remove a low-level interface from the IPMI driver. This will
>
Thanks, Corey.
Regards,
Tony
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] ipmi: Don't allow device module unload when in use
2019-10-16 12:18 ` tony camuso
@ 2019-10-16 13:13 ` tony camuso
0 siblings, 0 replies; 8+ messages in thread
From: tony camuso @ 2019-10-16 13:13 UTC (permalink / raw)
To: minyard; +Cc: openipmi-developer, linux-kernel, Corey Minyard
On 10/16/19 8:18 AM, tony camuso wrote:
> On 10/14/19 11:46 AM, minyard@acm.org wrote:
>> From: Corey Minyard <cminyard@mvista.com>
>>
>> If something has the IPMI driver open, don't allow the device
>> module to be unloaded. Before it would unload and the user would
>> get errors on use.
>>
>> This change is made on user request, and it makes it consistent
>> with the I2C driver, which has the same behavior.
>>
>> It does change things a little bit with respect to kernel users.
>> If the ACPI or IPMI watchdog (or any other kernel user) has
>> created a user, then the device module cannot be unloaded. Before
>> it could be unloaded,
>>
>> This does not affect hot-plug. If the device goes away (it's on
>> something removable that is removed or is hot-removed via sysfs)
>> then it still behaves as it did before.
>>
>> Reported-by: tony camuso <tcamuso@redhat.com>
>> Signed-off-by: Corey Minyard <cminyard@mvista.com>
>> ---
>> Tony, here is a suggested change for this. Can you look it over and
>> see if it looks ok?
>>
>> Thanks,
>>
>> -corey
>>
>> drivers/char/ipmi/ipmi_msghandler.c | 23 ++++++++++++++++-------
>> include/linux/ipmi_smi.h | 12 ++++++++----
>> 2 files changed, 24 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
>> index 2aab80e19ae0..15680de18625 100644
>> --- a/drivers/char/ipmi/ipmi_msghandler.c
>> +++ b/drivers/char/ipmi/ipmi_msghandler.c
>> @@ -448,6 +448,8 @@ enum ipmi_stat_indexes {
>> #define IPMI_IPMB_NUM_SEQ 64
>> struct ipmi_smi {
>> + struct module *owner;
>> +
>> /* What interface number are we? */
>> int intf_num;
>> @@ -1220,6 +1222,11 @@ int ipmi_create_user(unsigned int if_num,
>> if (rv)
>> goto out_kfree;
>> + if (!try_module_get(intf->owner)) {
>> + rv = -ENODEV;
>> + goto out_kfree;
>> + }
>> +
>> /* Note that each existing user holds a refcount to the interface. */
>> kref_get(&intf->refcount);
>> @@ -1349,6 +1356,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
>> }
>> kref_put(&intf->refcount, intf_free);
>> + module_put(intf->owner);
>> }
>> int ipmi_destroy_user(struct ipmi_user *user)
>> @@ -2459,7 +2467,7 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
>> * been recently fetched, this will just use the cached data. Otherwise
>> * it will run a new fetch.
>> *
>> - * Except for the first time this is called (in ipmi_register_smi()),
>> + * Except for the first time this is called (in ipmi_add_smi()),
>> * this will always return good data;
>> */
>> static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
>> @@ -3377,10 +3385,11 @@ static void redo_bmc_reg(struct work_struct *work)
>> kref_put(&intf->refcount, intf_free);
>> }
>> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>> - void *send_info,
>> - struct device *si_dev,
>> - unsigned char slave_addr)
>> +int ipmi_add_smi(struct module *owner,
>> + const struct ipmi_smi_handlers *handlers,
>> + void *send_info,
>> + struct device *si_dev,
>> + unsigned char slave_addr)
>> {
>> int i, j;
>> int rv;
>> @@ -3406,7 +3415,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>> return rv;
>> }
>> -
>> + intf->owner = owner;
>> intf->bmc = &intf->tmp_bmc;
>> INIT_LIST_HEAD(&intf->bmc->intfs);
>> mutex_init(&intf->bmc->dyn_mutex);
>> @@ -3514,7 +3523,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>> return rv;
>> }
>> -EXPORT_SYMBOL(ipmi_register_smi);
>> +EXPORT_SYMBOL(ipmi_add_smi);
>> static void deliver_smi_err_response(struct ipmi_smi *intf,
>> struct ipmi_smi_msg *msg,
>> diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
>> index 4dc66157d872..deec18b8944a 100644
>> --- a/include/linux/ipmi_smi.h
>> +++ b/include/linux/ipmi_smi.h
>> @@ -224,10 +224,14 @@ static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd,
>> * is called, and the lower layer must get the interface from that
>> * call.
>> */
>> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>> - void *send_info,
>> - struct device *dev,
>> - unsigned char slave_addr);
>> +int ipmi_add_smi(struct module *owner,
>> + const struct ipmi_smi_handlers *handlers,
>> + void *send_info,
>> + struct device *dev,
>> + unsigned char slave_addr);
>> +
>> +#define ipmi_register_smi(handlers, send_info, dev, slave_addr) \
>> + ipmi_add_smi(THIS_MODULE, handlers, send_info, dev, slave_addr)
>> /*
>> * Remove a low-level interface from the IPMI driver. This will
>>
>
> Thanks, Corey.
>
> Regards,
> Tony
>
And I meant to add that I will be testing this over the next couple days.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] ipmi: Don't allow device module unload when in use
2019-10-14 15:46 ` [PATCH] ipmi: Don't allow device module unload when in use minyard
2019-10-16 12:18 ` tony camuso
@ 2019-10-16 19:25 ` Tony Camuso
2019-10-16 19:33 ` Corey Minyard
2019-10-22 14:29 ` Tony Camuso
2 siblings, 1 reply; 8+ messages in thread
From: Tony Camuso @ 2019-10-16 19:25 UTC (permalink / raw)
To: minyard; +Cc: openipmi-developer, linux-kernel, Corey Minyard
On 10/14/19 11:46 AM, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
>
> If something has the IPMI driver open, don't allow the device
> module to be unloaded. Before it would unload and the user would
> get errors on use.
>
> This change is made on user request, and it makes it consistent
> with the I2C driver, which has the same behavior.
>
> It does change things a little bit with respect to kernel users.
> If the ACPI or IPMI watchdog (or any other kernel user) has
> created a user, then the device module cannot be unloaded. Before
> it could be unloaded,
>
> This does not affect hot-plug. If the device goes away (it's on
> something removable that is removed or is hot-removed via sysfs)
> then it still behaves as it did before.
>
> Reported-by: tony camuso <tcamuso@redhat.com>
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> ---
> Tony, here is a suggested change for this. Can you look it over and
> see if it looks ok?
>
> Thanks,
>
> -corey
>
> drivers/char/ipmi/ipmi_msghandler.c | 23 ++++++++++++++++-------
> include/linux/ipmi_smi.h | 12 ++++++++----
> 2 files changed, 24 insertions(+), 11 deletions(-)
Hi Corey.
You changed ipmi_register_ipmi to ipmi_add_ipmi in ipmi_msghandler, but you
did not change it where it is actually called.
# grep ipmi_register_smi drivers/char/ipmi/*.c
drivers/char/ipmi/ipmi_powernv.c: rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi, dev, 0);
drivers/char/ipmi/ipmi_si_intf.c: rv = ipmi_register_smi(&handlers,
drivers/char/ipmi/ipmi_ssif.c: rv = ipmi_register_smi(&ssif_info->handlers,
Is there a reason for changing the interface name? Is this something
that I could do instead of troubling you with it?
Regards,
Tony
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index 2aab80e19ae0..15680de18625 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -448,6 +448,8 @@ enum ipmi_stat_indexes {
>
> #define IPMI_IPMB_NUM_SEQ 64
> struct ipmi_smi {
> + struct module *owner;
> +
> /* What interface number are we? */
> int intf_num;
>
> @@ -1220,6 +1222,11 @@ int ipmi_create_user(unsigned int if_num,
> if (rv)
> goto out_kfree;
>
> + if (!try_module_get(intf->owner)) {
> + rv = -ENODEV;
> + goto out_kfree;
> + }
> +
> /* Note that each existing user holds a refcount to the interface. */
> kref_get(&intf->refcount);
>
> @@ -1349,6 +1356,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
> }
>
> kref_put(&intf->refcount, intf_free);
> + module_put(intf->owner);
> }
>
> int ipmi_destroy_user(struct ipmi_user *user)
> @@ -2459,7 +2467,7 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
> * been recently fetched, this will just use the cached data. Otherwise
> * it will run a new fetch.
> *
> - * Except for the first time this is called (in ipmi_register_smi()),
> + * Except for the first time this is called (in ipmi_add_smi()),
> * this will always return good data;
> */
> static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
> @@ -3377,10 +3385,11 @@ static void redo_bmc_reg(struct work_struct *work)
> kref_put(&intf->refcount, intf_free);
> }
>
> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> - void *send_info,
> - struct device *si_dev,
> - unsigned char slave_addr)
> +int ipmi_add_smi(struct module *owner,
> + const struct ipmi_smi_handlers *handlers,
> + void *send_info,
> + struct device *si_dev,
> + unsigned char slave_addr)
> {
> int i, j;
> int rv;
> @@ -3406,7 +3415,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> return rv;
> }
>
> -
> + intf->owner = owner;
> intf->bmc = &intf->tmp_bmc;
> INIT_LIST_HEAD(&intf->bmc->intfs);
> mutex_init(&intf->bmc->dyn_mutex);
> @@ -3514,7 +3523,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>
> return rv;
> }
> -EXPORT_SYMBOL(ipmi_register_smi);
> +EXPORT_SYMBOL(ipmi_add_smi);
>
> static void deliver_smi_err_response(struct ipmi_smi *intf,
> struct ipmi_smi_msg *msg,
> diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
> index 4dc66157d872..deec18b8944a 100644
> --- a/include/linux/ipmi_smi.h
> +++ b/include/linux/ipmi_smi.h
> @@ -224,10 +224,14 @@ static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd,
> * is called, and the lower layer must get the interface from that
> * call.
> */
> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> - void *send_info,
> - struct device *dev,
> - unsigned char slave_addr);
> +int ipmi_add_smi(struct module *owner,
> + const struct ipmi_smi_handlers *handlers,
> + void *send_info,
> + struct device *dev,
> + unsigned char slave_addr);
> +
> +#define ipmi_register_smi(handlers, send_info, dev, slave_addr) \
> + ipmi_add_smi(THIS_MODULE, handlers, send_info, dev, slave_addr)
>
> /*
> * Remove a low-level interface from the IPMI driver. This will
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] ipmi: Don't allow device module unload when in use
2019-10-16 19:25 ` Tony Camuso
@ 2019-10-16 19:33 ` Corey Minyard
2019-10-16 19:54 ` Tony Camuso
0 siblings, 1 reply; 8+ messages in thread
From: Corey Minyard @ 2019-10-16 19:33 UTC (permalink / raw)
To: Tony Camuso; +Cc: openipmi-developer, linux-kernel, Corey Minyard
On Wed, Oct 16, 2019 at 03:25:56PM -0400, Tony Camuso wrote:
> On 10/14/19 11:46 AM, minyard@acm.org wrote:
> > From: Corey Minyard <cminyard@mvista.com>
> >
> > If something has the IPMI driver open, don't allow the device
> > module to be unloaded. Before it would unload and the user would
> > get errors on use.
> >
> > This change is made on user request, and it makes it consistent
> > with the I2C driver, which has the same behavior.
> >
> > It does change things a little bit with respect to kernel users.
> > If the ACPI or IPMI watchdog (or any other kernel user) has
> > created a user, then the device module cannot be unloaded. Before
> > it could be unloaded,
> >
> > This does not affect hot-plug. If the device goes away (it's on
> > something removable that is removed or is hot-removed via sysfs)
> > then it still behaves as it did before.
> >
> > Reported-by: tony camuso <tcamuso@redhat.com>
> > Signed-off-by: Corey Minyard <cminyard@mvista.com>
> > ---
> > Tony, here is a suggested change for this. Can you look it over and
> > see if it looks ok?
> >
> > Thanks,
> >
> > -corey
> >
> > drivers/char/ipmi/ipmi_msghandler.c | 23 ++++++++++++++++-------
> > include/linux/ipmi_smi.h | 12 ++++++++----
> > 2 files changed, 24 insertions(+), 11 deletions(-)
>
> Hi Corey.
>
> You changed ipmi_register_ipmi to ipmi_add_ipmi in ipmi_msghandler, but you
> did not change it where it is actually called.
>
> # grep ipmi_register_smi drivers/char/ipmi/*.c
> drivers/char/ipmi/ipmi_powernv.c: rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi, dev, 0);
> drivers/char/ipmi/ipmi_si_intf.c: rv = ipmi_register_smi(&handlers,
> drivers/char/ipmi/ipmi_ssif.c: rv = ipmi_register_smi(&ssif_info->handlers,
>
> Is there a reason for changing the interface name? Is this something
> that I could do instead of troubling you with it?
I don't understand. You don't say that anything went wrong, you just
referenced something I changed.
I changed the name so I could create a macro with that name to pass in
the module name. Pretty standard to do in the kernel. Is there a
compile or runtime issue?
-corey
>
> Regards,
> Tony
>
>
> >
> > diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> > index 2aab80e19ae0..15680de18625 100644
> > --- a/drivers/char/ipmi/ipmi_msghandler.c
> > +++ b/drivers/char/ipmi/ipmi_msghandler.c
> > @@ -448,6 +448,8 @@ enum ipmi_stat_indexes {
> > #define IPMI_IPMB_NUM_SEQ 64
> > struct ipmi_smi {
> > + struct module *owner;
> > +
> > /* What interface number are we? */
> > int intf_num;
> > @@ -1220,6 +1222,11 @@ int ipmi_create_user(unsigned int if_num,
> > if (rv)
> > goto out_kfree;
> > + if (!try_module_get(intf->owner)) {
> > + rv = -ENODEV;
> > + goto out_kfree;
> > + }
> > +
> > /* Note that each existing user holds a refcount to the interface. */
> > kref_get(&intf->refcount);
> > @@ -1349,6 +1356,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
> > }
> > kref_put(&intf->refcount, intf_free);
> > + module_put(intf->owner);
> > }
> > int ipmi_destroy_user(struct ipmi_user *user)
> > @@ -2459,7 +2467,7 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
> > * been recently fetched, this will just use the cached data. Otherwise
> > * it will run a new fetch.
> > *
> > - * Except for the first time this is called (in ipmi_register_smi()),
> > + * Except for the first time this is called (in ipmi_add_smi()),
> > * this will always return good data;
> > */
> > static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
> > @@ -3377,10 +3385,11 @@ static void redo_bmc_reg(struct work_struct *work)
> > kref_put(&intf->refcount, intf_free);
> > }
> > -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> > - void *send_info,
> > - struct device *si_dev,
> > - unsigned char slave_addr)
> > +int ipmi_add_smi(struct module *owner,
> > + const struct ipmi_smi_handlers *handlers,
> > + void *send_info,
> > + struct device *si_dev,
> > + unsigned char slave_addr)
> > {
> > int i, j;
> > int rv;
> > @@ -3406,7 +3415,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> > return rv;
> > }
> > -
> > + intf->owner = owner;
> > intf->bmc = &intf->tmp_bmc;
> > INIT_LIST_HEAD(&intf->bmc->intfs);
> > mutex_init(&intf->bmc->dyn_mutex);
> > @@ -3514,7 +3523,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> > return rv;
> > }
> > -EXPORT_SYMBOL(ipmi_register_smi);
> > +EXPORT_SYMBOL(ipmi_add_smi);
> > static void deliver_smi_err_response(struct ipmi_smi *intf,
> > struct ipmi_smi_msg *msg,
> > diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
> > index 4dc66157d872..deec18b8944a 100644
> > --- a/include/linux/ipmi_smi.h
> > +++ b/include/linux/ipmi_smi.h
> > @@ -224,10 +224,14 @@ static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd,
> > * is called, and the lower layer must get the interface from that
> > * call.
> > */
> > -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> > - void *send_info,
> > - struct device *dev,
> > - unsigned char slave_addr);
> > +int ipmi_add_smi(struct module *owner,
> > + const struct ipmi_smi_handlers *handlers,
> > + void *send_info,
> > + struct device *dev,
> > + unsigned char slave_addr);
> > +
> > +#define ipmi_register_smi(handlers, send_info, dev, slave_addr) \
> > + ipmi_add_smi(THIS_MODULE, handlers, send_info, dev, slave_addr)
> > /*
> > * Remove a low-level interface from the IPMI driver. This will
> >
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] ipmi: Don't allow device module unload when in use
2019-10-16 19:33 ` Corey Minyard
@ 2019-10-16 19:54 ` Tony Camuso
0 siblings, 0 replies; 8+ messages in thread
From: Tony Camuso @ 2019-10-16 19:54 UTC (permalink / raw)
To: minyard; +Cc: openipmi-developer, linux-kernel, Corey Minyard
On 10/16/19 3:33 PM, Corey Minyard wrote:
> On Wed, Oct 16, 2019 at 03:25:56PM -0400, Tony Camuso wrote:
>> On 10/14/19 11:46 AM, minyard@acm.org wrote:
>>> From: Corey Minyard <cminyard@mvista.com>
>>>
>>> If something has the IPMI driver open, don't allow the device
>>> module to be unloaded. Before it would unload and the user would
>>> get errors on use.
>>>
>>> This change is made on user request, and it makes it consistent
>>> with the I2C driver, which has the same behavior.
>>>
>>> It does change things a little bit with respect to kernel users.
>>> If the ACPI or IPMI watchdog (or any other kernel user) has
>>> created a user, then the device module cannot be unloaded. Before
>>> it could be unloaded,
>>>
>>> This does not affect hot-plug. If the device goes away (it's on
>>> something removable that is removed or is hot-removed via sysfs)
>>> then it still behaves as it did before.
>>>
>>> Reported-by: tony camuso <tcamuso@redhat.com>
>>> Signed-off-by: Corey Minyard <cminyard@mvista.com>
>>> ---
>>> Tony, here is a suggested change for this. Can you look it over and
>>> see if it looks ok?
>>>
>>> Thanks,
>>>
>>> -corey
>>>
>>> drivers/char/ipmi/ipmi_msghandler.c | 23 ++++++++++++++++-------
>>> include/linux/ipmi_smi.h | 12 ++++++++----
>>> 2 files changed, 24 insertions(+), 11 deletions(-)
>>
>> Hi Corey.
>>
>> You changed ipmi_register_ipmi to ipmi_add_ipmi in ipmi_msghandler, but you
>> did not change it where it is actually called.
>>
>> # grep ipmi_register_smi drivers/char/ipmi/*.c
>> drivers/char/ipmi/ipmi_powernv.c: rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi, dev, 0);
>> drivers/char/ipmi/ipmi_si_intf.c: rv = ipmi_register_smi(&handlers,
>> drivers/char/ipmi/ipmi_ssif.c: rv = ipmi_register_smi(&ssif_info->handlers,
>>
>> Is there a reason for changing the interface name? Is this something
>> that I could do instead of troubling you with it?
>
> I don't understand. You don't say that anything went wrong, you just
> referenced something I changed.
>
> I changed the name so I could create a macro with that name to pass in
> the module name. Pretty standard to do in the kernel.
Can't believe I missed that.
> Is there a
> compile or runtime issue?
>
> -corey
All is well, so far. Haven't finished testing.
>>
>> Regards,
>> Tony
>>
>>
>>>
>>> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
>>> index 2aab80e19ae0..15680de18625 100644
>>> --- a/drivers/char/ipmi/ipmi_msghandler.c
>>> +++ b/drivers/char/ipmi/ipmi_msghandler.c
>>> @@ -448,6 +448,8 @@ enum ipmi_stat_indexes {
>>> #define IPMI_IPMB_NUM_SEQ 64
>>> struct ipmi_smi {
>>> + struct module *owner;
>>> +
>>> /* What interface number are we? */
>>> int intf_num;
>>> @@ -1220,6 +1222,11 @@ int ipmi_create_user(unsigned int if_num,
>>> if (rv)
>>> goto out_kfree;
>>> + if (!try_module_get(intf->owner)) {
>>> + rv = -ENODEV;
>>> + goto out_kfree;
>>> + }
>>> +
>>> /* Note that each existing user holds a refcount to the interface. */
>>> kref_get(&intf->refcount);
>>> @@ -1349,6 +1356,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
>>> }
>>> kref_put(&intf->refcount, intf_free);
>>> + module_put(intf->owner);
>>> }
>>> int ipmi_destroy_user(struct ipmi_user *user)
>>> @@ -2459,7 +2467,7 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
>>> * been recently fetched, this will just use the cached data. Otherwise
>>> * it will run a new fetch.
>>> *
>>> - * Except for the first time this is called (in ipmi_register_smi()),
>>> + * Except for the first time this is called (in ipmi_add_smi()),
>>> * this will always return good data;
>>> */
>>> static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
>>> @@ -3377,10 +3385,11 @@ static void redo_bmc_reg(struct work_struct *work)
>>> kref_put(&intf->refcount, intf_free);
>>> }
>>> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>>> - void *send_info,
>>> - struct device *si_dev,
>>> - unsigned char slave_addr)
>>> +int ipmi_add_smi(struct module *owner,
>>> + const struct ipmi_smi_handlers *handlers,
>>> + void *send_info,
>>> + struct device *si_dev,
>>> + unsigned char slave_addr)
>>> {
>>> int i, j;
>>> int rv;
>>> @@ -3406,7 +3415,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>>> return rv;
>>> }
>>> -
>>> + intf->owner = owner;
>>> intf->bmc = &intf->tmp_bmc;
>>> INIT_LIST_HEAD(&intf->bmc->intfs);
>>> mutex_init(&intf->bmc->dyn_mutex);
>>> @@ -3514,7 +3523,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>>> return rv;
>>> }
>>> -EXPORT_SYMBOL(ipmi_register_smi);
>>> +EXPORT_SYMBOL(ipmi_add_smi);
>>> static void deliver_smi_err_response(struct ipmi_smi *intf,
>>> struct ipmi_smi_msg *msg,
>>> diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
>>> index 4dc66157d872..deec18b8944a 100644
>>> --- a/include/linux/ipmi_smi.h
>>> +++ b/include/linux/ipmi_smi.h
>>> @@ -224,10 +224,14 @@ static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd,
>>> * is called, and the lower layer must get the interface from that
>>> * call.
>>> */
>>> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>>> - void *send_info,
>>> - struct device *dev,
>>> - unsigned char slave_addr);
>>> +int ipmi_add_smi(struct module *owner,
>>> + const struct ipmi_smi_handlers *handlers,
>>> + void *send_info,
>>> + struct device *dev,
>>> + unsigned char slave_addr);
>>> +
>>> +#define ipmi_register_smi(handlers, send_info, dev, slave_addr) \
>>> + ipmi_add_smi(THIS_MODULE, handlers, send_info, dev, slave_addr)
>>> /*
>>> * Remove a low-level interface from the IPMI driver. This will
>>>
>>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] ipmi: Don't allow device module unload when in use
2019-10-14 15:46 ` [PATCH] ipmi: Don't allow device module unload when in use minyard
2019-10-16 12:18 ` tony camuso
2019-10-16 19:25 ` Tony Camuso
@ 2019-10-22 14:29 ` Tony Camuso
2019-10-22 15:56 ` Corey Minyard
2 siblings, 1 reply; 8+ messages in thread
From: Tony Camuso @ 2019-10-22 14:29 UTC (permalink / raw)
To: minyard; +Cc: openipmi-developer, linux-kernel, Corey Minyard
Corey,
Testing shows that this patch works as expected.
Regards,
Tony
On 10/14/19 11:46 AM, minyard@acm.org wrote:
> From: Corey Minyard <cminyard@mvista.com>
>
> If something has the IPMI driver open, don't allow the device
> module to be unloaded. Before it would unload and the user would
> get errors on use.
>
> This change is made on user request, and it makes it consistent
> with the I2C driver, which has the same behavior.
>
> It does change things a little bit with respect to kernel users.
> If the ACPI or IPMI watchdog (or any other kernel user) has
> created a user, then the device module cannot be unloaded. Before
> it could be unloaded,
>
> This does not affect hot-plug. If the device goes away (it's on
> something removable that is removed or is hot-removed via sysfs)
> then it still behaves as it did before.
>
> Reported-by: tony camuso <tcamuso@redhat.com>
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> ---
> Tony, here is a suggested change for this. Can you look it over and
> see if it looks ok?
>
> Thanks,
>
> -corey
>
> drivers/char/ipmi/ipmi_msghandler.c | 23 ++++++++++++++++-------
> include/linux/ipmi_smi.h | 12 ++++++++----
> 2 files changed, 24 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index 2aab80e19ae0..15680de18625 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -448,6 +448,8 @@ enum ipmi_stat_indexes {
>
> #define IPMI_IPMB_NUM_SEQ 64
> struct ipmi_smi {
> + struct module *owner;
> +
> /* What interface number are we? */
> int intf_num;
>
> @@ -1220,6 +1222,11 @@ int ipmi_create_user(unsigned int if_num,
> if (rv)
> goto out_kfree;
>
> + if (!try_module_get(intf->owner)) {
> + rv = -ENODEV;
> + goto out_kfree;
> + }
> +
> /* Note that each existing user holds a refcount to the interface. */
> kref_get(&intf->refcount);
>
> @@ -1349,6 +1356,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
> }
>
> kref_put(&intf->refcount, intf_free);
> + module_put(intf->owner);
> }
>
> int ipmi_destroy_user(struct ipmi_user *user)
> @@ -2459,7 +2467,7 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
> * been recently fetched, this will just use the cached data. Otherwise
> * it will run a new fetch.
> *
> - * Except for the first time this is called (in ipmi_register_smi()),
> + * Except for the first time this is called (in ipmi_add_smi()),
> * this will always return good data;
> */
> static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
> @@ -3377,10 +3385,11 @@ static void redo_bmc_reg(struct work_struct *work)
> kref_put(&intf->refcount, intf_free);
> }
>
> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> - void *send_info,
> - struct device *si_dev,
> - unsigned char slave_addr)
> +int ipmi_add_smi(struct module *owner,
> + const struct ipmi_smi_handlers *handlers,
> + void *send_info,
> + struct device *si_dev,
> + unsigned char slave_addr)
> {
> int i, j;
> int rv;
> @@ -3406,7 +3415,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> return rv;
> }
>
> -
> + intf->owner = owner;
> intf->bmc = &intf->tmp_bmc;
> INIT_LIST_HEAD(&intf->bmc->intfs);
> mutex_init(&intf->bmc->dyn_mutex);
> @@ -3514,7 +3523,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
>
> return rv;
> }
> -EXPORT_SYMBOL(ipmi_register_smi);
> +EXPORT_SYMBOL(ipmi_add_smi);
>
> static void deliver_smi_err_response(struct ipmi_smi *intf,
> struct ipmi_smi_msg *msg,
> diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
> index 4dc66157d872..deec18b8944a 100644
> --- a/include/linux/ipmi_smi.h
> +++ b/include/linux/ipmi_smi.h
> @@ -224,10 +224,14 @@ static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd,
> * is called, and the lower layer must get the interface from that
> * call.
> */
> -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> - void *send_info,
> - struct device *dev,
> - unsigned char slave_addr);
> +int ipmi_add_smi(struct module *owner,
> + const struct ipmi_smi_handlers *handlers,
> + void *send_info,
> + struct device *dev,
> + unsigned char slave_addr);
> +
> +#define ipmi_register_smi(handlers, send_info, dev, slave_addr) \
> + ipmi_add_smi(THIS_MODULE, handlers, send_info, dev, slave_addr)
>
> /*
> * Remove a low-level interface from the IPMI driver. This will
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] ipmi: Don't allow device module unload when in use
2019-10-22 14:29 ` Tony Camuso
@ 2019-10-22 15:56 ` Corey Minyard
0 siblings, 0 replies; 8+ messages in thread
From: Corey Minyard @ 2019-10-22 15:56 UTC (permalink / raw)
To: Tony Camuso; +Cc: openipmi-developer, linux-kernel, Corey Minyard
On Tue, Oct 22, 2019 at 10:29:12AM -0400, Tony Camuso wrote:
> Corey,
>
> Testing shows that this patch works as expected.
Thanks, I'll add a Tested-by for you. It's queued for the next merge
window.
-corey
>
> Regards,
> Tony
>
>
> On 10/14/19 11:46 AM, minyard@acm.org wrote:
> > From: Corey Minyard <cminyard@mvista.com>
> >
> > If something has the IPMI driver open, don't allow the device
> > module to be unloaded. Before it would unload and the user would
> > get errors on use.
> >
> > This change is made on user request, and it makes it consistent
> > with the I2C driver, which has the same behavior.
> >
> > It does change things a little bit with respect to kernel users.
> > If the ACPI or IPMI watchdog (or any other kernel user) has
> > created a user, then the device module cannot be unloaded. Before
> > it could be unloaded,
> >
> > This does not affect hot-plug. If the device goes away (it's on
> > something removable that is removed or is hot-removed via sysfs)
> > then it still behaves as it did before.
> >
> > Reported-by: tony camuso <tcamuso@redhat.com>
> > Signed-off-by: Corey Minyard <cminyard@mvista.com>
> > ---
> > Tony, here is a suggested change for this. Can you look it over and
> > see if it looks ok?
> >
> > Thanks,
> >
> > -corey
> >
> > drivers/char/ipmi/ipmi_msghandler.c | 23 ++++++++++++++++-------
> > include/linux/ipmi_smi.h | 12 ++++++++----
> > 2 files changed, 24 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> > index 2aab80e19ae0..15680de18625 100644
> > --- a/drivers/char/ipmi/ipmi_msghandler.c
> > +++ b/drivers/char/ipmi/ipmi_msghandler.c
> > @@ -448,6 +448,8 @@ enum ipmi_stat_indexes {
> > #define IPMI_IPMB_NUM_SEQ 64
> > struct ipmi_smi {
> > + struct module *owner;
> > +
> > /* What interface number are we? */
> > int intf_num;
> > @@ -1220,6 +1222,11 @@ int ipmi_create_user(unsigned int if_num,
> > if (rv)
> > goto out_kfree;
> > + if (!try_module_get(intf->owner)) {
> > + rv = -ENODEV;
> > + goto out_kfree;
> > + }
> > +
> > /* Note that each existing user holds a refcount to the interface. */
> > kref_get(&intf->refcount);
> > @@ -1349,6 +1356,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
> > }
> > kref_put(&intf->refcount, intf_free);
> > + module_put(intf->owner);
> > }
> > int ipmi_destroy_user(struct ipmi_user *user)
> > @@ -2459,7 +2467,7 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc)
> > * been recently fetched, this will just use the cached data. Otherwise
> > * it will run a new fetch.
> > *
> > - * Except for the first time this is called (in ipmi_register_smi()),
> > + * Except for the first time this is called (in ipmi_add_smi()),
> > * this will always return good data;
> > */
> > static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc,
> > @@ -3377,10 +3385,11 @@ static void redo_bmc_reg(struct work_struct *work)
> > kref_put(&intf->refcount, intf_free);
> > }
> > -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> > - void *send_info,
> > - struct device *si_dev,
> > - unsigned char slave_addr)
> > +int ipmi_add_smi(struct module *owner,
> > + const struct ipmi_smi_handlers *handlers,
> > + void *send_info,
> > + struct device *si_dev,
> > + unsigned char slave_addr)
> > {
> > int i, j;
> > int rv;
> > @@ -3406,7 +3415,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> > return rv;
> > }
> > -
> > + intf->owner = owner;
> > intf->bmc = &intf->tmp_bmc;
> > INIT_LIST_HEAD(&intf->bmc->intfs);
> > mutex_init(&intf->bmc->dyn_mutex);
> > @@ -3514,7 +3523,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> > return rv;
> > }
> > -EXPORT_SYMBOL(ipmi_register_smi);
> > +EXPORT_SYMBOL(ipmi_add_smi);
> > static void deliver_smi_err_response(struct ipmi_smi *intf,
> > struct ipmi_smi_msg *msg,
> > diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
> > index 4dc66157d872..deec18b8944a 100644
> > --- a/include/linux/ipmi_smi.h
> > +++ b/include/linux/ipmi_smi.h
> > @@ -224,10 +224,14 @@ static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd,
> > * is called, and the lower layer must get the interface from that
> > * call.
> > */
> > -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
> > - void *send_info,
> > - struct device *dev,
> > - unsigned char slave_addr);
> > +int ipmi_add_smi(struct module *owner,
> > + const struct ipmi_smi_handlers *handlers,
> > + void *send_info,
> > + struct device *dev,
> > + unsigned char slave_addr);
> > +
> > +#define ipmi_register_smi(handlers, send_info, dev, slave_addr) \
> > + ipmi_add_smi(THIS_MODULE, handlers, send_info, dev, slave_addr)
> > /*
> > * Remove a low-level interface from the IPMI driver. This will
> >
>
^ permalink raw reply [flat|nested] 8+ messages in thread