Nov 30 2009

arch/alpha/kernel: Add kmalloc NULL tests 

Author: Julia Lawall <julia@diku.dk>

Check that the result of kmalloc is not NULL before passing it to other
functions.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// 
@@
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
)
// 

Signed-off-by: Julia Lawall 
Cc: Ivan Kokshaysky 
Cc: Richard Henderson 
Signed-off-by: Matt Turner 

---
 arch/alpha/kernel/core_marvel.c | 2 ++
 arch/alpha/kernel/core_titan.c  | 2 ++
 2 files changed, 4 insertions(+)
 
diff --git a/arch/alpha/kernel/core_marvel.c b/arch/alpha/kernel/core_marvel.c
index 8e059e5..53dd2f1 100644
--- a/arch/alpha/kernel/core_marvel.c
+++ b/arch/alpha/kernel/core_marvel.c
@@ -1103,6 +1103,8 @@ marvel_agp_info(void)
 	 * Allocate the info structure.
 	 */
 	agp = kmalloc(sizeof(*agp), GFP_KERNEL);
+	if (!agp)
+		return NULL;
 
 	/*
 	 * Fill it in.
diff --git a/arch/alpha/kernel/core_titan.c b/arch/alpha/kernel/core_titan.c
index 7668649..219bf27 100644
--- a/arch/alpha/kernel/core_titan.c
+++ b/arch/alpha/kernel/core_titan.c
@@ -757,6 +757,8 @@ titan_agp_info(void)
 	 * Allocate the info structure.
 	 */
 	agp = kmalloc(sizeof(*agp), GFP_KERNEL);
+	if (!agp)
+		return NULL;
 
 	/*
 	 * Fill it in.

qlambert