>-----Original Message----- >From: linux-media-owner@xxxxxxxxxxxxxxx [mailto:linux-media- >owner@xxxxxxxxxxxxxxx] On Behalf Of akpm@xxxxxxxxxxxxxxxxxxxx >Sent: Thursday, March 11, 2010 5:02 PM >To: mchehab@xxxxxxxxxxxxx >Cc: linux-media@xxxxxxxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx; julia@xxxxxxx >Subject: [patch 2/5] drivers/media/video: move dereference after NULL test > >From: Julia Lawall <julia@xxxxxxx> > >In quickcam_messenger.c, if the NULL test on uvd is needed, then the >dereference should be after the NULL test. > >In vpif_display.c, std_info is initialized to the address of a structure >field. This seems unlikely to be NULL. If it could somehow be NULL, then >the assignment should be moved after the NULL test. Alternatively, perhaps >the NULL test is intended to test std_info->stdid rather than std_info? > >In saa7134-alsa.c, the function is only called from one place, where the >chip argument has already been dereferenced. On the other hand, if it >should be kept, then card should be initialized after it. > >A simplified version of the semantic match that detects this problem is as >follows (http://coccinelle.lip6.fr/): > >// <smpl> >@match exists@ >expression x, E; >identifier fld; >@@ > >* x->fld > ... when != \(x = E\|&x\) >* x == NULL >// </smpl> > >Signed-off-by: Julia Lawall <julia@xxxxxxx> >Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx> >Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >--- > > drivers/media/video/davinci/vpif_display.c | 2 -- > drivers/media/video/saa7134/saa7134-alsa.c | 2 -- > drivers/media/video/usbvideo/quickcam_messenger.c | 3 ++- > 3 files changed, 2 insertions(+), 5 deletions(-) > >diff -puN drivers/media/video/davinci/vpif_display.c~drivers-media-video- >move-dereference-after-null-test drivers/media/video/davinci/vpif_display.c >--- a/drivers/media/video/davinci/vpif_display.c~drivers-media-video-move- >dereference-after-null-test >+++ a/drivers/media/video/davinci/vpif_display.c >@@ -383,8 +383,6 @@ static int vpif_get_std_info(struct chan > int index; > > std_info->stdid = vid_ch->stdid; >- if (!std_info) >- return -1; Please change it as if (!std_info->stdid) return -1; Murali > > for (index = 0; index < ARRAY_SIZE(ch_params); index++) { > config = &ch_params[index]; >diff -puN drivers/media/video/saa7134/saa7134-alsa.c~drivers-media-video- >move-dereference-after-null-test drivers/media/video/saa7134/saa7134-alsa.c >--- a/drivers/media/video/saa7134/saa7134-alsa.c~drivers-media-video-move- >dereference-after-null-test >+++ a/drivers/media/video/saa7134/saa7134-alsa.c >@@ -1011,8 +1011,6 @@ static int snd_card_saa7134_new_mixer(sn > unsigned int idx; > int err, addr; > >- if (snd_BUG_ON(!chip)) >- return -EINVAL; > strcpy(card->mixername, "SAA7134 Mixer"); > > for (idx = 0; idx < ARRAY_SIZE(snd_saa7134_volume_controls); idx++) { >diff -puN drivers/media/video/usbvideo/quickcam_messenger.c~drivers-media- >video-move-dereference-after-null-test >drivers/media/video/usbvideo/quickcam_messenger.c >--- a/drivers/media/video/usbvideo/quickcam_messenger.c~drivers-media- >video-move-dereference-after-null-test >+++ a/drivers/media/video/usbvideo/quickcam_messenger.c >@@ -692,12 +692,13 @@ static int qcm_start_data(struct uvd *uv > > static void qcm_stop_data(struct uvd *uvd) > { >- struct qcm *cam = (struct qcm *) uvd->user_data; >+ struct qcm *cam; > int i, j; > int ret; > > if ((uvd == NULL) || (!uvd->streaming) || (uvd->dev == NULL)) > return; >+ cam = (struct qcm *) uvd->user_data; > > ret = qcm_camera_off(uvd); > if (ret) >_ >-- >To unsubscribe from this list: send the line "unsubscribe linux-media" in >the body of a message to majordomo@xxxxxxxxxxxxxxx >More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
