[PATCH 20/21] arch/blackfin: Add kmalloc NULL tests

From: Mike Frysinger
Date: Thu Jul 16 2009 - 20:06:43 EST


From: Julia Lawall <julia@xxxxxxx>

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

In the first two cases, the new code returns -ENOMEM, which seems
compatible with what is done for similar functions for other architectures.

In the last two cases, the new code fails silently, ie just returns,
because the function has void return type.

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

// <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>
Signed-off-by: Sonic Zhang <sonic.zhang@xxxxxxxxxx>
Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxx>
---
arch/blackfin/mach-common/smp.c | 8 ++++++++
1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index e6e3429..349ee3f 100644
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -211,6 +211,8 @@ int smp_call_function(void (*func)(void *info), void *info, int wait)
return 0;

msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+ if (!msg)
+ return -ENOMEM;
INIT_LIST_HEAD(&msg->list);
msg->call_struct.func = func;
msg->call_struct.info = info;
@@ -252,6 +254,8 @@ int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
cpu_set(cpu, callmap);

msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+ if (!msg)
+ return -ENOMEM;
INIT_LIST_HEAD(&msg->list);
msg->call_struct.func = func;
msg->call_struct.info = info;
@@ -287,6 +291,8 @@ void smp_send_reschedule(int cpu)
return;

msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+ if (!msg)
+ return;
memset(msg, 0, sizeof(msg));
INIT_LIST_HEAD(&msg->list);
msg->type = BFIN_IPI_RESCHEDULE;
@@ -314,6 +320,8 @@ void smp_send_stop(void)
return;

msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+ if (!msg)
+ return;
memset(msg, 0, sizeof(msg));
INIT_LIST_HEAD(&msg->list);
msg->type = BFIN_IPI_CPU_STOP;
--
1.6.3.3

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