From julia@diku.dk Thu Jun 3 10:50:26 2010 From: Julia Lawall Date: Thu, 27 May 2010 14:37:19 +0200 (CEST) Subject: Staging: Eliminate a NULL pointer dereference To: Greg Kroah-Hartman , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Message-ID: From: Julia Lawall Eliminate a NULL or near NULL pointer dereference. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @r exists@ expression E,E1; identifier f; statement S1,S2,S3; @@ if ((E == NULL && ...) || ...) { ... when != if (...) S1 else S2 when != E = E1 * E->f ... when any return ...; } else S3 // Signed-off-by: Julia Lawall Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/usbdux.c | 3 +-- drivers/staging/dt3155/allocator.c | 4 +--- 2 files changed, 2 insertions(+), 5 deletions(-) --- a/drivers/staging/comedi/drivers/usbdux.c +++ b/drivers/staging/comedi/drivers/usbdux.c @@ -351,8 +351,7 @@ static int usbdux_ai_stop(struct usbduxs int ret = 0; if (!this_usbduxsub) { - dev_err(&this_usbduxsub->interface->dev, - "comedi?: usbdux_ai_stop: this_usbduxsub=NULL!\n"); + pr_err("comedi?: usbdux_ai_stop: this_usbduxsub=NULL!\n"); return -EFAULT; } dev_dbg(&this_usbduxsub->interface->dev, "comedi: usbdux_ai_stop\n"); --- a/drivers/staging/dt3155/allocator.c +++ b/drivers/staging/dt3155/allocator.c @@ -176,9 +176,7 @@ int allocator_free_dma(unsigned long add prev = ptr; ptr = ptr->next; if (!ptr) { - printk(KERN_ERR ALL_MSG - "free_dma(0x%08lx) but add. not allocated\n", - ptr->address); + pr_err(ALL_MSG "free_dma but add. not allocated\n"); return -EINVAL; } PDEBUGG("freeing: %08lx (%li) next %08lx\n", ptr->address, ptr->size,