[PATCH] uio: Destroy uio_idr on module exit

[PATCH] uio: Destroy uio_idr on module exit

[Johannes Thumshirn]

Destroy uio_idr on module exit, reclaiming the allocated memory.

This was detected by the following semantic patch (written by Luis Rodriguez
<mcgrof@suse.com>)
<SmPL>
@ defines_module_init @
declarer name module_init, module_exit;
declarer name DEFINE_IDR;
identifier init;
@@

module_init(init);

@ defines_module_exit @
identifier exit;
@@

module_exit(exit);

@ declares_idr depends on defines_module_init && defines_module_exit @
identifier idr;
@@

DEFINE_IDR(idr);

@ on_exit_calls_destroy depends on declares_idr && defines_module_exit @
identifier declares_idr.idr, defines_module_exit.exit;
@@

exit(void)
{
 ...
 idr_destroy(&idr);
 ...
}

@ missing_module_idr_destroy depends on declares_idr && defines_module_exit && !on_exit_calls_destroy @
identifier declares_idr.idr, defines_module_exit.exit;
@@

exit(void)
{
 ...
 +idr_destroy(&idr);
}

</SmPL>

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/uio/uio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 3257d42..8196581 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -896,6 +896,7 @@ static int __init uio_init(void)
 static void __exit uio_exit(void)
 {
 	release_uio_class();
+	idr_destroy(&uio_idr);
 }
 
 module_init(uio_init)
-- 
2.4.3

Re: [PATCH] uio: Destroy uio_idr on module exit

[Greg Kroah-Hartman]

On Wed, Jul 08, 2015 at 05:24:46PM +0200, Johannes Thumshirn wrote:
> Destroy uio_idr on module exit, reclaiming the allocated memory.
> 
> This was detected by the following semantic patch (written by Luis Rodriguez
> <mcgrof@suse.com>)
> <SmPL>
> @ defines_module_init @
> declarer name module_init, module_exit;
> declarer name DEFINE_IDR;
> identifier init;
> @@
> 
> module_init(init);
> 
> @ defines_module_exit @
> identifier exit;
> @@
> 
> module_exit(exit);
> 
> @ declares_idr depends on defines_module_init && defines_module_exit @
> identifier idr;
> @@
> 
> DEFINE_IDR(idr);
> 
> @ on_exit_calls_destroy depends on declares_idr && defines_module_exit @
> identifier declares_idr.idr, defines_module_exit.exit;
> @@
> 
> exit(void)
> {
>  ...
>  idr_destroy(&idr);
>  ...
> }
> 
> @ missing_module_idr_destroy depends on declares_idr && defines_module_exit && !on_exit_calls_destroy @
> identifier declares_idr.idr, defines_module_exit.exit;
> @@
> 
> exit(void)
> {
>  ...
>  +idr_destroy(&idr);
> }
> 
> </SmPL>
> 
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>

Nice work.  Shouldn't we do the same thing for ida_destroy() as well?  I
see 4 USB drivers that need this same fix for that structure.

thanks,

greg k-h

Re: [PATCH] uio: Destroy uio_idr on module exit

[Johannes Thumshirn]

Greg Kroah-Hartman <gregkh@linuxfoundation.org> writes:

> On Wed, Jul 08, 2015 at 05:24:46PM +0200, Johannes Thumshirn wrote:
>> Destroy uio_idr on module exit, reclaiming the allocated memory.
>> 
>> This was detected by the following semantic patch (written by Luis Rodriguez
>> <mcgrof@suse.com>)
>> <SmPL>
>> @ defines_module_init @
>> declarer name module_init, module_exit;
>> declarer name DEFINE_IDR;
>> identifier init;
>> @@
>> 
>> module_init(init);
>> 
>> @ defines_module_exit @
>> identifier exit;
>> @@
>> 
>> module_exit(exit);
>> 
>> @ declares_idr depends on defines_module_init && defines_module_exit @
>> identifier idr;
>> @@
>> 
>> DEFINE_IDR(idr);
>> 
>> @ on_exit_calls_destroy depends on declares_idr && defines_module_exit @
>> identifier declares_idr.idr, defines_module_exit.exit;
>> @@
>> 
>> exit(void)
>> {
>>  ...
>>  idr_destroy(&idr);
>>  ...
>> }
>> 
>> @ missing_module_idr_destroy depends on declares_idr && defines_module_exit && !on_exit_calls_destroy @
>> identifier declares_idr.idr, defines_module_exit.exit;
>> @@
>> 
>> exit(void)
>> {
>>  ...
>>  +idr_destroy(&idr);
>> }
>> 
>> </SmPL>
>> 
>> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
>
> Nice work.  Shouldn't we do the same thing for ida_destroy() as well?  I
> see 4 USB drivers that need this same fix for that structure.
>

Can you tell me which? I've send overall 13 patches for this (no series
as get_maintainers.pl for the series spit out > 30 Recipients so I
refused to send spam).

Maybe/probably I forgot one (or two).

Johannes

-- 
Johannes Thumshirn                                       Storage
jthumshirn@suse.de                             +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)

Re: [PATCH] uio: Destroy uio_idr on module exit

[Greg Kroah-Hartman]

On Thu, Jul 09, 2015 at 08:48:36AM +0200, Johannes Thumshirn wrote:
> Greg Kroah-Hartman <gregkh@linuxfoundation.org> writes:
> 
> > On Wed, Jul 08, 2015 at 05:24:46PM +0200, Johannes Thumshirn wrote:
> >> Destroy uio_idr on module exit, reclaiming the allocated memory.
> >> 
> >> This was detected by the following semantic patch (written by Luis Rodriguez
> >> <mcgrof@suse.com>)
> >> <SmPL>
> >> @ defines_module_init @
> >> declarer name module_init, module_exit;
> >> declarer name DEFINE_IDR;
> >> identifier init;
> >> @@
> >> 
> >> module_init(init);
> >> 
> >> @ defines_module_exit @
> >> identifier exit;
> >> @@
> >> 
> >> module_exit(exit);
> >> 
> >> @ declares_idr depends on defines_module_init && defines_module_exit @
> >> identifier idr;
> >> @@
> >> 
> >> DEFINE_IDR(idr);
> >> 
> >> @ on_exit_calls_destroy depends on declares_idr && defines_module_exit @
> >> identifier declares_idr.idr, defines_module_exit.exit;
> >> @@
> >> 
> >> exit(void)
> >> {
> >>  ...
> >>  idr_destroy(&idr);
> >>  ...
> >> }
> >> 
> >> @ missing_module_idr_destroy depends on declares_idr && defines_module_exit && !on_exit_calls_destroy @
> >> identifier declares_idr.idr, defines_module_exit.exit;
> >> @@
> >> 
> >> exit(void)
> >> {
> >>  ...
> >>  +idr_destroy(&idr);
> >> }
> >> 
> >> </SmPL>
> >> 
> >> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> >
> > Nice work.  Shouldn't we do the same thing for ida_destroy() as well?  I
> > see 4 USB drivers that need this same fix for that structure.
> >
> 
> Can you tell me which? I've send overall 13 patches for this (no series
> as get_maintainers.pl for the series spit out > 30 Recipients so I
> refused to send spam).
> 
> Maybe/probably I forgot one (or two).

You need to look for "ida_destroy" not just "idr_destroy", here's the
ones I found in just a few seconds of looking:

~/linux/gregkh $ cd drivers/usb/
~/linux/gregkh/drivers/usb $ cg ida_destroy
~/linux/gregkh/drivers/usb $ cg DEFINE_IDA
0 chipidea/core.c             597 static DEFINE_IDA(ci_ida);
1 gadget/function/f_hid.c      31 static DEFINE_IDA(hidg_ida);
2 gadget/function/f_printer.c  60 static DEFINE_IDA(printer_ida);
3 gadget/function/rndis.c      67 static DEFINE_IDA(rndis_ida);

There's 4 users that never free memory when the module is unloaded for
the ida structure.

thanks,

greg k-h