Re: [PATCH 13/15] drivers/usb/musb/omap2430.c: adjust duplicate test

Re: [PATCH 13/15] drivers/usb/musb/omap2430.c: adjust duplicate test

[Felipe Balbi]

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Hi,

On Mon, Jan 21, 2013 at 02:02:57PM +0100, Julia Lawall wrote:
> From: Julia Lawall <Julia.Lawall@lip6.fr>
> 
> Delete successive tests to the same location.  Data is the just previously
> allocated and tested value.  Test the result of the allocation made here
> instead.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @s exists@
> local idexpression y;
> expression x,e;
> @@
> 
> *if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
>  { ... when forall
>    return ...; }
> ... when != \(y = e\|y += e\|y -= e\|y |= e\|y &= e\|y++\|y--\|&y\)
>     when != \(XT_GETPAGE(...,y)\|WMI_CMD_BUF(...)\)
> *if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
>  { ... when forall
>    return ...; }
> // </smpl>
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

Already in my tree ;-)

commit b37457d80bc3e2a6bb86a6036c572574614a7631
Author: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Date:   Tue Jan 8 22:11:14 2013 +0300

    usb: musb: omap2430: fix wrong devm_kzalloc() result check
    
    Commit 00a0b1d58af873d842580dcac55f3b156c3a4077 (usb: musb: omap: Add device
    tree support for omap musb glue) assigns result of devm_kzalloc() call to
    the 'config' variable but then checks for NULL the 'data' variable (already
    checked after previous call). Thus we risk a kernel oops further when data
    pointed by 'config' is written to by subsequent of_property_read_u32() calls
    iff the allocation happens to fail...
    
    Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
    Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c
index b15bb05..bb48796 100644
--- a/drivers/usb/musb/omap2430.c
+++ b/drivers/usb/musb/omap2430.c
@@ -543,7 +543,7 @@ static int omap2430_probe(struct platform_device *pdev)
 		}
 
 		config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL);
-		if (!data) {
+		if (!config) {
 			dev_err(&pdev->dev,
 				"failed to allocate musb hdrc config\n");
 			goto err2;

-- 
balbi

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[PATCH 13/15] drivers/usb/musb/omap2430.c: adjust duplicate test

[Julia Lawall]

From: Julia Lawall <Julia.Lawall@lip6.fr>

Delete successive tests to the same location.  Data is the just previously
allocated and tested value.  Test the result of the allocation made here
instead.

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

// <smpl>
@s exists@
local idexpression y;
expression x,e;
@@

*if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
 { ... when forall
   return ...; }
... when != \(y = e\|y += e\|y -= e\|y |= e\|y &= e\|y++\|y--\|&y\)
    when != \(XT_GETPAGE(...,y)\|WMI_CMD_BUF(...)\)
*if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
 { ... when forall
   return ...; }
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
The previous code could be further simplified by removing the
initializations of ret to -ENOMEM, as is absent in this case.  But that is
probably for another patch.

 drivers/usb/musb/omap2430.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c
index da00af4..533c4fd 100644
--- a/drivers/usb/musb/omap2430.c
+++ b/drivers/usb/musb/omap2430.c
@@ -545,7 +545,7 @@ static int omap2430_probe(struct platform_device *pdev)
 		}
 
 		config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL);
-		if (!data) {
+		if (!config) {
 			dev_err(&pdev->dev,
 				"failed to allocate musb hdrc config\n");
 			goto err2;

Re: [PATCH 13/15] drivers/usb/musb/omap2430.c: adjust duplicate test

[Sergei Shtylyov]

On 21-01-2013 17:02, Julia Lawall wrote:

> From: Julia Lawall <Julia.Lawall@lip6.fr>

> Delete successive tests to the same location.  Data is the just previously
> allocated and tested value.  Test the result of the allocation made here
> instead.

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

> // <smpl>
> @s exists@
> local idexpression y;
> expression x,e;
> @@

> *if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
>   { ... when forall
>     return ...; }
> ... when != \(y = e\|y += e\|y -= e\|y |= e\|y &= e\|y++\|y--\|&y\)
>      when != \(XT_GETPAGE(...,y)\|WMI_CMD_BUF(...)\)
> *if ( \(x == NULL\|IS_ERR(x)\|y != 0\) )
>   { ... when forall
>     return ...; }
> // </smpl>

> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

> ---
> The previous code could be further simplified by removing the
> initializations of ret to -ENOMEM, as is absent in this case.  But that is
> probably for another patch.

    I've already sent such patch and Felipe has queued it.

>   drivers/usb/musb/omap2430.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c
> index da00af4..533c4fd 100644
> --- a/drivers/usb/musb/omap2430.c
> +++ b/drivers/usb/musb/omap2430.c
> @@ -545,7 +545,7 @@ static int omap2430_probe(struct platform_device *pdev)
>   		}
>
>   		config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL);
> -		if (!data) {
> +		if (!config) {

    Same about this change. You're a bit late this time. :-)

WBR, Sergei