Re: [PATCH 1/3] arch/powerpc: Add kmalloc NULL tests

From: Julia Lawall
Date: Fri Aug 07 2009 - 03:05:49 EST


From: Julia Lawall <julia@xxxxxxx>

Check that the result of kmalloc/kzalloc is not NULL before dereferencing it.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression *x;
identifier f;
constant char *C;
@@

x = \(kmalloc\|kcalloc\|kzalloc\)(...);
... when != x == NULL
when != x != NULL
when != (x || ...)
(
kfree(x)
|
f(...,C,...,x,...)
|
*f(...,x,...)
|
*x->f
)
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
arch/powerpc/sysdev/fsl_rio.c | 18 ++++++++++++++----
1 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/sysdev/fsl_rio.c b/arch/powerpc/sysdev/fsl_rio.c
index cbb3bed..757a83f 100644
--- a/arch/powerpc/sysdev/fsl_rio.c
+++ b/arch/powerpc/sysdev/fsl_rio.c
@@ -1057,6 +1057,10 @@ int fsl_rio_setup(struct of_device *dev)
law_start, law_size);

ops = kmalloc(sizeof(struct rio_ops), GFP_KERNEL);
+ if (!ops) {
+ rc = -ENOMEM;
+ goto err_ops;
+ }
ops->lcread = fsl_local_config_read;
ops->lcwrite = fsl_local_config_write;
ops->cread = fsl_rio_config_read;
@@ -1064,6 +1068,10 @@ int fsl_rio_setup(struct of_device *dev)
ops->dsend = fsl_rio_doorbell_send;

port = kzalloc(sizeof(struct rio_mport), GFP_KERNEL);
+ if (!port) {
+ rc = -ENOMEM;
+ goto err_port;
+ }
port->id = 0;
port->index = 0;

@@ -1071,7 +1079,7 @@ int fsl_rio_setup(struct of_device *dev)
if (!priv) {
printk(KERN_ERR "Can't alloc memory for 'priv'\n");
rc = -ENOMEM;
- goto err;
+ goto err_priv;
}

INIT_LIST_HEAD(&port->dbells);
@@ -1169,11 +1177,13 @@ int fsl_rio_setup(struct of_device *dev)

return 0;
err:
- if (priv)
- iounmap(priv->regs_win);
- kfree(ops);
+ iounmap(priv->regs_win);
kfree(priv);
+err_priv:
kfree(port);
+err_port:
+ kfree(ops);
+err_ops:
return rc;
}

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