[PATCH -next] ipmi: fix module param sparse warnings

[PATCH -next] ipmi: fix module param sparse warnings

[Randy Dunlap]

From: Randy Dunlap <randy.dunlap@oracle.com>

The <arg> parameter in module_param_cb() should be a pointer,
i.e., like one of these:
	union {
		void *arg;
		const struct kparam_string *str;
		const struct kparam_array *arr;
	};

sparse complains:
drivers/char/ipmi/ipmi_watchdog.c:303:1: error: cannot dereference this type
drivers/char/ipmi/ipmi_watchdog.c:307:1: error: cannot dereference this type
drivers/char/ipmi/ipmi_watchdog.c:311:1: error: cannot dereference this type

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Corey Minyard <minyard@acm.org>
---
Note: patch is against linux-next, since these lines have changed recently.

 drivers/char/ipmi/ipmi_watchdog.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- linux-next-20100528.orig/drivers/char/ipmi/ipmi_watchdog.c
+++ linux-next-20100528/drivers/char/ipmi/ipmi_watchdog.c
@@ -300,15 +300,15 @@ MODULE_PARM_DESC(timeout, "Timeout value
 module_param(pretimeout, timeout, 0644);
 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
 
-module_param_cb(action, &param_ops_str, action_op, 0644);
+module_param_cb(action, &param_ops_str, &action_op, 0644);
 MODULE_PARM_DESC(action, "Timeout action. One of: "
 		 "reset, none, power_cycle, power_off.");
 
-module_param_cb(preaction, &param_ops_str, preaction_op, 0644);
+module_param_cb(preaction, &param_ops_str, &preaction_op, 0644);
 MODULE_PARM_DESC(preaction, "Pretimeout action.  One of: "
 		 "pre_none, pre_smi, pre_nmi, pre_int.");
 
-module_param_cb(preop, &param_ops_str, preop_op, 0644);
+module_param_cb(preop, &param_ops_str, &preop_op, 0644);
 MODULE_PARM_DESC(preop, "Pretimeout driver operation.  One of: "
 		 "preop_none, preop_panic, preop_give_data.");
 

Re: [PATCH -next] ipmi: fix module param sparse warnings

[Rusty Russell]

On Fri, 25 Jun 2010 07:51:22 am Randy Dunlap wrote:
> From: Randy Dunlap <randy.dunlap@oracle.com>
> 
> The <arg> parameter in module_param_cb() should be a pointer,

Well, I don't think there's anything wrong with it being a function.

The actual problem is that it tries to figure out if the arg is a bool
or an int: if someone wants to work through the 700-odd cases of 
module_param*bool and convert those vars to actual bools, that'd allow
us to get rid of that logic.

Meanwhile, we can do this instead.  Does it solve it as well?

Subject: ipmi: fix module param sparse warnings
Date: Thu, 24 Jun 2010 15:21:22 -0700
From: Randy Dunlap <randy.dunlap@oracle.com>

The <arg> parameter in module_param_cb() should be a pointer,
i.e., like one of these:
	union {
		void *arg;
		const struct kparam_string *str;
		const struct kparam_array *arr;
	};

sparse complains:
drivers/char/ipmi/ipmi_watchdog.c:303:1: error: cannot dereference this type
drivers/char/ipmi/ipmi_watchdog.c:307:1: error: cannot dereference this type
drivers/char/ipmi/ipmi_watchdog.c:311:1: error: cannot dereference this type

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Corey Minyard <minyard@acm.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/char/ipmi/ipmi_watchdog.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- linux-next-20100528.orig/drivers/char/ipmi/ipmi_watchdog.c
+++ linux-next-20100528/drivers/char/ipmi/ipmi_watchdog.c
@@ -300,15 +300,15 @@ MODULE_PARM_DESC(timeout, "Timeout value
 module_param(pretimeout, timeout, 0644);
 MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
 
-module_param_cb(action, &param_ops_str, action_op, 0644);
+module_param_cb(action, &param_ops_str, &action_op, 0644);
 MODULE_PARM_DESC(action, "Timeout action. One of: "
 		 "reset, none, power_cycle, power_off.");
 
-module_param_cb(preaction, &param_ops_str, preaction_op, 0644);
+module_param_cb(preaction, &param_ops_str, &preaction_op, 0644);
 MODULE_PARM_DESC(preaction, "Pretimeout action.  One of: "
 		 "pre_none, pre_smi, pre_nmi, pre_int.");
 
-module_param_cb(preop, &param_ops_str, preop_op, 0644);
+module_param_cb(preop, &param_ops_str, &preop_op, 0644);
 MODULE_PARM_DESC(preop, "Pretimeout driver operation.  One of: "
 		 "preop_none, preop_panic, preop_give_data.");
 

Re: [PATCH -next] ipmi: fix module param sparse warnings

[Randy Dunlap]

On 06/25/10 05:50, Rusty Russell wrote:
> On Fri, 25 Jun 2010 07:51:22 am Randy Dunlap wrote:
>> From: Randy Dunlap <randy.dunlap@oracle.com>
>>
>> The <arg> parameter in module_param_cb() should be a pointer,
> 
> Well, I don't think there's anything wrong with it being a function.

Ah, yes, I see.  That makes it a sparse error, right?

> The actual problem is that it tries to figure out if the arg is a bool
> or an int: if someone wants to work through the 700-odd cases of 
> module_param*bool and convert those vars to actual bools, that'd allow
> us to get rid of that logic.
> 
> Meanwhile, we can do this instead.  Does it solve it as well?

Yes, that also fixes it.
Thanks.

> Subject: ipmi: fix module param sparse warnings
> Date: Thu, 24 Jun 2010 15:21:22 -0700
> From: Randy Dunlap <randy.dunlap@oracle.com>
> 
> The <arg> parameter in module_param_cb() should be a pointer,
> i.e., like one of these:
> 	union {
> 		void *arg;
> 		const struct kparam_string *str;
> 		const struct kparam_array *arr;
> 	};
> 
> sparse complains:
> drivers/char/ipmi/ipmi_watchdog.c:303:1: error: cannot dereference this type
> drivers/char/ipmi/ipmi_watchdog.c:307:1: error: cannot dereference this type
> drivers/char/ipmi/ipmi_watchdog.c:311:1: error: cannot dereference this type
> 
> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
> Cc: Corey Minyard <minyard@acm.org>
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> ---
>  drivers/char/ipmi/ipmi_watchdog.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> --- linux-next-20100528.orig/drivers/char/ipmi/ipmi_watchdog.c
> +++ linux-next-20100528/drivers/char/ipmi/ipmi_watchdog.c
> @@ -300,15 +300,15 @@ MODULE_PARM_DESC(timeout, "Timeout value
>  module_param(pretimeout, timeout, 0644);
>  MODULE_PARM_DESC(pretimeout, "Pretimeout value in seconds.");
>  
> -module_param_cb(action, &param_ops_str, action_op, 0644);
> +module_param_cb(action, &param_ops_str, &action_op, 0644);
>  MODULE_PARM_DESC(action, "Timeout action. One of: "
>  		 "reset, none, power_cycle, power_off.");
>  
> -module_param_cb(preaction, &param_ops_str, preaction_op, 0644);
> +module_param_cb(preaction, &param_ops_str, &preaction_op, 0644);
>  MODULE_PARM_DESC(preaction, "Pretimeout action.  One of: "
>  		 "pre_none, pre_smi, pre_nmi, pre_int.");
>  
> -module_param_cb(preop, &param_ops_str, preop_op, 0644);
> +module_param_cb(preop, &param_ops_str, &preop_op, 0644);
>  MODULE_PARM_DESC(preop, "Pretimeout driver operation.  One of: "
>  		 "preop_none, preop_panic, preop_give_data.");
>  
> 
> 


-- 
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: [PATCH -next] ipmi: fix module param sparse warnings

[Rusty Russell]

On Sat, 26 Jun 2010 01:51:13 am Randy Dunlap wrote:
> On 06/25/10 05:50, Rusty Russell wrote:
> > On Fri, 25 Jun 2010 07:51:22 am Randy Dunlap wrote:
> >> From: Randy Dunlap <randy.dunlap@oracle.com>
> >>
> >> The <arg> parameter in module_param_cb() should be a pointer,
> > 
> > Well, I don't think there's anything wrong with it being a function.
> 
> Ah, yes, I see.  That makes it a sparse error, right?

Well, it's a weird corner case, but yes.

> > Meanwhile, we can do this instead.  Does it solve it as well?
> 
> Yes, that also fixes it.
> Thanks.

Thanks, I've added your tested-by.

Cheers,
Rusty.