Patchwork [4/20,V2] drivers/net/can/sja1000/peak_pcmcia.c: fix error return code

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Submitter Peter Senna Tschudin
Date Oct. 5, 2012, 8:41 p.m.
Message ID <1349469667-6137-4-git-send-email-peter.senna@gmail.com>
Download mbox | patch
Permalink /patch/189594/
State Not Applicable
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Comments

Peter Senna Tschudin - Oct. 5, 2012, 8:41 p.m.
From: Peter Senna Tschudin <peter.senna@gmail.com>

The function pcan_probe() return 0 for success and negative value
for most of its internal tests failures. There is one exception
that is error case going to probe_err_4:. Fore this error case, the
function abort its success execution path but returns non negative
value, making it difficult for a caller function to notice the error.

This patch fixes the error case that do not return negative value.

This was found by Coccinelle, but the code change was made by hand.
This patch is not robot generated.

A simplified version of the semantic match that finds this problem is
as follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>

---
Change from V1:
        Updated commit message. See:
        http://www.kernelhub.org/?p=2&msg=139319

 drivers/net/can/sja1000/peak_pcmcia.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)


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Marc Kleine-Budde - Oct. 5, 2012, 9:07 p.m.
On 10/05/2012 10:41 PM, Peter Senna Tschudin wrote:
> From: Peter Senna Tschudin <peter.senna@gmail.com>
> 
> The function pcan_probe() return 0 for success and negative value
> for most of its internal tests failures. There is one exception
> that is error case going to probe_err_4:. Fore this error case, the
> function abort its success execution path but returns non negative
> value, making it difficult for a caller function to notice the error.
> 
> This patch fixes the error case that do not return negative value.
> 
> This was found by Coccinelle, but the code change was made by hand.
> This patch is not robot generated.
> 
> A simplified version of the semantic match that finds this problem is
> as follows: (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> (
> if@p1 (\(ret < 0\|ret != 0\))
>  { ... return ret; }
> |
> ret@p1 = 0
> )
> ... when != ret = e1
>     when != &ret
> *if(...)
> {
>   ... when != ret = e2
>       when forall
>  return ret;
> }
> // </smpl>
> 
> Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>


Too late, v1 of this patch is already in net/master

regards, Marc
David Miller - Oct. 7, 2012, 6:38 p.m.
This patch was already in the tree.
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Patch

diff --git a/drivers/net/can/sja1000/peak_pcmcia.c b/drivers/net/can/sja1000/peak_pcmcia.c
index ec6bd9d..272a85f 100644
--- a/drivers/net/can/sja1000/peak_pcmcia.c
+++ b/drivers/net/can/sja1000/peak_pcmcia.c
@@ -686,8 +686,10 @@  static int __devinit pcan_probe(struct pcmcia_device *pdev)
 
 	/* detect available channels */
 	pcan_add_channels(card);
-	if (!card->chan_count)
+	if (!card->chan_count) {
+		err = -ENOMEM;
 		goto probe_err_4;
+	}
 
 	/* init the timer which controls the leds */
 	init_timer(&card->led_timer);