Re: [PATCH] video_device: don't free_irq() an element past arrayvpif_obj.dev[] and fix test

From: Roel Kluin
Date: Fri Feb 19 2010 - 18:20:49 EST


The first loop ends when platform_get_resource() returns NULL. Can it occur
that no platform_get_resource() succeeded? I think we should error return if
that happens. Could k grow larger than VPIF_DISPLAY_MAX_DEVICES there? Should
we err out in that case?

In the loop `for (i = 0; i < VPIF_DISPLAY_MAX_DEVICES; i++)' if
video_device_alloc() fails I think we correctly release the devices, but we
have to do more before we reach label vpif_int_err.

As mentioned, we left the first loop with a res of NULL, which is dereferenced
at label vpif_int_err. So we have to get the resource again, however, k was
incremented at the end of that loop as well. Also i used as index in the second
loop as well should point to res->end before going to label vpif_int_err, to
free all requested irqs. All this needs to be done for later error labels as
well, so a new label is added where this occurs, alloc_vid_fail.

Variable k can't be reused in the third for-loop and at label probe_out. As
mentioned k is needed to get the resource in case a error and clean-up is
required.

If we reach label vpif_int_err, res shouldn't be NULL, since we dereference it.
Previously we had:

for (; k >= 0; k--) {
for (m = i; m >= res->start; m--)
free_irq(m, (void *)(&vpif_obj.dev[k]->channel_id));
res = platform_get_resource(pdev, IORESOURCE_IRQ, k-1);
m = res->end;
}

In the last iteration k equals 0, so we call platform_get_resource() with -1 as
a third argument. Since platform_get_resource() uses an unsigned it is
converted to 0xffffffff. platform_get_resource() fails for every index and
returns NULL. A test is lacking and we dereference NULL.

The error "VPIF IRQ request failed" should only be displayed when request_irq()
failed, not in the case of other errors.

Also I changed some indexes, so a few could be removed.

Signed-off-by: Roel Kluin <roel.kluin@xxxxxxxxx>
---
> I think there were many more issues:

> I must admit I did not compile test this, except with checkpatch.pl, but I
> think the issues are real and should be fixed. Comments?

I would like to compile test but cannot compile test these because of errors
like drivers/net/davinci_emac.c:69:11: error: unable to open 'mach/dm646x.h'

I found these three other functions in davinci code that have very similar
problems. The changelog is about vpif_probe() in vpif_display.c.

Since the functions are somewhat similar, maybe code should be shared, but
where should one put that?

Roel

drivers/media/video/davinci/vpif_capture.c | 63 +++++++++++++----------
drivers/media/video/davinci/vpif_display.c | 76 ++++++++++++++++++----------
drivers/net/davinci_emac.c | 64 ++++++++++++++++--------
3 files changed, 129 insertions(+), 74 deletions(-)

diff --git a/drivers/media/video/davinci/vpif_capture.c b/drivers/media/video/davinci/vpif_capture.c
index 7813072..096e727 100644
--- a/drivers/media/video/davinci/vpif_capture.c
+++ b/drivers/media/video/davinci/vpif_capture.c
@@ -1915,7 +1915,7 @@ static __init int vpif_probe(struct platform_device *pdev)
{
struct vpif_subdev_info *subdevdata;
struct vpif_capture_config *config;
- int i, j, k, m, q, err;
+ int i, j, k, err;
struct i2c_adapter *i2c_adap;
struct channel_obj *ch;
struct common_obj *common;
@@ -1936,14 +1936,18 @@ static __init int vpif_probe(struct platform_device *pdev)
for (i = res->start; i <= res->end; i++) {
if (request_irq(i, vpif_channel_isr, IRQF_DISABLED,
"DM646x_Capture",
- (void *)(&vpif_obj.dev[k]->channel_id))) {
- err = -EBUSY;
+ &vpif_obj.dev[k]->channel_id)) {
i--;
+ err = -EBUSY;
goto vpif_int_err;
}
}
k++;
+ if (k >= VPIF_DISPLAY_MAX_DEVICES)
+ break;
}
+ if (k == 0)
+ return -ENODEV;

for (i = 0; i < VPIF_CAPTURE_MAX_DEVICES; i++) {
/* Get the pointer to the channel object */
@@ -1972,16 +1976,16 @@ static __init int vpif_probe(struct platform_device *pdev)
ch->video_dev = vfd;
}

- for (j = 0; j < VPIF_CAPTURE_MAX_DEVICES; j++) {
- ch = vpif_obj.dev[j];
- ch->channel_id = j;
+ for (i = 0; i < VPIF_CAPTURE_MAX_DEVICES; i++) {
+ ch = vpif_obj.dev[i];
+ ch->channel_id = i;
common = &(ch->common[VPIF_VIDEO_INDEX]);
spin_lock_init(&common->irqlock);
mutex_init(&common->lock);
/* Initialize prio member of channel object */
v4l2_prio_init(&ch->prio);
err = video_register_device(ch->video_dev,
- VFL_TYPE_GRABBER, (j ? 1 : 0));
+ VFL_TYPE_GRABBER, (i ? 1 : 0));
if (err)
goto probe_out;

@@ -2007,24 +2011,24 @@ static __init int vpif_probe(struct platform_device *pdev)
goto probe_subdev_out;
}

- for (i = 0; i < subdev_count; i++) {
- subdevdata = &config->subdev_info[i];
- vpif_obj.sd[i] =
+ for (j = 0; j < subdev_count; j++) {
+ subdevdata = &config->subdev_info[j];
+ vpif_obj.sd[j] =
v4l2_i2c_new_subdev_board(&vpif_obj.v4l2_dev,
i2c_adap,
subdevdata->name,
&subdevdata->board_info,
NULL);

- if (!vpif_obj.sd[i]) {
+ if (!vpif_obj.sd[j]) {
vpif_err("Error registering v4l2 subdevice\n");
goto probe_subdev_out;
}
v4l2_info(&vpif_obj.v4l2_dev, "registered sub device %s\n",
subdevdata->name);

- if (vpif_obj.sd[i])
- vpif_obj.sd[i]->grp_id = 1 << i;
+ if (vpif_obj.sd[j])
+ vpif_obj.sd[j]->grp_id = 1 << j;
}
v4l2_info(&vpif_obj.v4l2_dev, "DM646x VPIF Capture driver"
" initialized\n");
@@ -2034,30 +2038,37 @@ static __init int vpif_probe(struct platform_device *pdev)
probe_subdev_out:
/* free sub devices memory */
kfree(vpif_obj.sd);
-
- j = VPIF_CAPTURE_MAX_DEVICES;
probe_out:
v4l2_device_unregister(&vpif_obj.v4l2_dev);
- for (k = 0; k < j; k++) {
+ for (j = 0; j < i; j++) {
/* Get the pointer to the channel object */
- ch = vpif_obj.dev[k];
+ ch = vpif_obj.dev[j];
/* Unregister video device */
video_unregister_device(ch->video_dev);
}

vpif_dev_alloc_err:
- k = VPIF_CAPTURE_MAX_DEVICES-1;
- res = platform_get_resource(pdev, IORESOURCE_IRQ, k);
+ while (k--) {
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, k);
+ if (res != NULL)
+ break;
+ vpif_err("Couldn't free irqs for resource %d.\n", k);
+ }
+ if (res == NULL)
+ return err;
i = res->end;
-
vpif_int_err:
- for (q = k; q >= 0; q--) {
- for (m = i; m >= (int)res->start; m--)
- free_irq(m, (void *)(&vpif_obj.dev[q]->channel_id));
+ for (j = i; j >= (int)res->start; j--)
+ free_irq(j, &vpif_obj.dev[k]->channel_id);

- res = platform_get_resource(pdev, IORESOURCE_IRQ, q-1);
- if (res)
- i = res->end;
+ while (k--) {
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, k);
+ if (res == NULL) {
+ vpif_err("Couldn't free irqs for resource %d.\n", k);
+ continue;
+ }
+ for (j = res->end; j >= (int)res->start; j--)
+ free_irq(j, &vpif_obj.dev[k]->channel_id);
}
return err;
}
diff --git a/drivers/media/video/davinci/vpif_display.c b/drivers/media/video/davinci/vpif_display.c
index dfddef7..6bcedbf 100644
--- a/drivers/media/video/davinci/vpif_display.c
+++ b/drivers/media/video/davinci/vpif_display.c
@@ -383,7 +383,7 @@ static int vpif_get_std_info(struct channel_obj *ch)
int index;

std_info->stdid = vid_ch->stdid;
- if (!std_info)
+ if (!std_info->stdid)
return -1;

for (index = 0; index < ARRAY_SIZE(ch_params); index++) {
@@ -1423,7 +1423,7 @@ static __init int vpif_probe(struct platform_device *pdev)
{
struct vpif_subdev_info *subdevdata;
struct vpif_display_config *config;
- int i, j = 0, k, q, m, err = 0;
+ int i, j, k, err;
struct i2c_adapter *i2c_adap;
struct common_obj *common;
struct channel_obj *ch;
@@ -1452,12 +1452,18 @@ static __init int vpif_probe(struct platform_device *pdev)
if (request_irq(i, vpif_channel_isr, IRQF_DISABLED,
"DM646x_Display",
(void *)(&vpif_obj.dev[k]->channel_id))) {
+ i--;
err = -EBUSY;
+ vpif_err("VPIF IRQ request failed\n");
goto vpif_int_err;
}
}
k++;
+ if (k >= VPIF_DISPLAY_MAX_DEVICES)
+ break;
}
+ if (k == 0)
+ return -ENODEV;

for (i = 0; i < VPIF_DISPLAY_MAX_DEVICES; i++) {

@@ -1472,7 +1478,7 @@ static __init int vpif_probe(struct platform_device *pdev)
video_device_release(ch->video_dev);
}
err = -ENOMEM;
- goto vpif_int_err;
+ goto alloc_vid_fail;
}

/* Initialize field of video device */
@@ -1489,13 +1495,13 @@ static __init int vpif_probe(struct platform_device *pdev)
ch->video_dev = vfd;
}

- for (j = 0; j < VPIF_DISPLAY_MAX_DEVICES; j++) {
- ch = vpif_obj.dev[j];
+ for (i = 0; i < VPIF_DISPLAY_MAX_DEVICES; i++) {
+ ch = vpif_obj.dev[i];
/* Initialize field of the channel objects */
atomic_set(&ch->usrs, 0);
- for (k = 0; k < VPIF_NUMOBJECTS; k++) {
- ch->common[k].numbuffers = 0;
- common = &ch->common[k];
+ for (j = 0; j < VPIF_NUMOBJECTS; j++) {
+ ch->common[j].numbuffers = 0;
+ common = &ch->common[j];
common->io_usrs = 0;
common->started = 0;
spin_lock_init(&common->irqlock);
@@ -1506,12 +1512,12 @@ static __init int vpif_probe(struct platform_device *pdev)
common->ctop_off = common->cbtm_off = 0;
common->cur_frm = common->next_frm = NULL;
memset(&common->fmt, 0, sizeof(common->fmt));
- common->numbuffers = config_params.numbuffers[k];
+ common->numbuffers = config_params.numbuffers[j];

}
ch->initialized = 0;
- ch->channel_id = j;
- if (j < 2)
+ ch->channel_id = i;
+ if (i < 2)
ch->common[VPIF_VIDEO_INDEX].numbuffers =
config_params.numbuffers[ch->channel_id];
else
@@ -1529,7 +1535,7 @@ static __init int vpif_probe(struct platform_device *pdev)
(int)ch, (int)&ch->video_dev);

err = video_register_device(ch->video_dev,
- VFL_TYPE_GRABBER, (j ? 3 : 2));
+ VFL_TYPE_GRABBER, (i ? 3 : 2));
if (err < 0)
goto probe_out;

@@ -1548,18 +1554,18 @@ static __init int vpif_probe(struct platform_device *pdev)
goto probe_out;
}

- for (i = 0; i < subdev_count; i++) {
- vpif_obj.sd[i] = v4l2_i2c_new_subdev_board(&vpif_obj.v4l2_dev,
- i2c_adap, subdevdata[i].name,
- &subdevdata[i].board_info,
+ for (j = 0; j < subdev_count; j++) {
+ vpif_obj.sd[j] = v4l2_i2c_new_subdev_board(&vpif_obj.v4l2_dev,
+ i2c_adap, subdevdata[j].name,
+ &subdevdata[j].board_info,
NULL);
- if (!vpif_obj.sd[i]) {
+ if (!vpif_obj.sd[j]) {
vpif_err("Error registering v4l2 subdevice\n");
goto probe_subdev_out;
}

- if (vpif_obj.sd[i])
- vpif_obj.sd[i]->grp_id = 1 << i;
+ if (vpif_obj.sd[j])
+ vpif_obj.sd[j]->grp_id = 1 << j;
}

return 0;
@@ -1567,20 +1573,36 @@ static __init int vpif_probe(struct platform_device *pdev)
probe_subdev_out:
kfree(vpif_obj.sd);
probe_out:
- for (k = 0; k < j; k++) {
- ch = vpif_obj.dev[k];
+ for (j = 0; j < i; j++) {
+ ch = vpif_obj.dev[j];
video_unregister_device(ch->video_dev);
video_device_release(ch->video_dev);
ch->video_dev = NULL;
}
+alloc_vid_fail:
+ while (k--) {
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, k);
+ if (res != NULL)
+ break;
+ vpif_err("Couldn't free irqs for resource %d.\n", k);
+ }
+ if (res == NULL)
+ return err;
+ i = res->end;
vpif_int_err:
v4l2_device_unregister(&vpif_obj.v4l2_dev);
- vpif_err("VPIF IRQ request failed\n");
- for (q = k; k >= 0; k--) {
- for (m = i; m >= res->start; m--)
- free_irq(m, (void *)(&vpif_obj.dev[k]->channel_id));
- res = platform_get_resource(pdev, IORESOURCE_IRQ, k-1);
- m = res->end;
+
+ for (j = i; j >= res->start; j--)
+ free_irq(j, (void *)(&vpif_obj.dev[k]->channel_id));
+
+ while (k--) {
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, k);
+ if (res == NULL) {
+ vpif_err("Couldn't free irqs for resource %d.\n", k);
+ continue;
+ }
+ for (j = res->end; j >= res->start; j--)
+ free_irq(j, (void *)(&vpif_obj.dev[k]->channel_id));
}

return err;
diff --git a/drivers/net/davinci_emac.c b/drivers/net/davinci_emac.c
index 33c4fe2..2faa9d3 100644
--- a/drivers/net/davinci_emac.c
+++ b/drivers/net/davinci_emac.c
@@ -2369,12 +2369,12 @@ static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
static int emac_dev_open(struct net_device *ndev)
{
struct device *emac_dev = &ndev->dev;
- u32 rc, cnt, ch;
+ u32 cnt, ch;
int phy_addr;
struct resource *res;
- int q, m;
- int i = 0;
+ int i, j, k, err;
int k = 0;
+ int err;
struct emac_priv *priv = netdev_priv(ndev);

netif_carrier_off(ndev);
@@ -2398,15 +2398,15 @@ static int emac_dev_open(struct net_device *ndev)
emac_write(EMAC_MACHASH2, 0);

/* multi ch not supported - open 1 TX, 1RX ch by default */
- rc = emac_init_txch(priv, EMAC_DEF_TX_CH);
- if (0 != rc) {
+ err = emac_init_txch(priv, EMAC_DEF_TX_CH);
+ if (err) {
dev_err(emac_dev, "DaVinci EMAC: emac_init_txch() failed");
- return rc;
+ return err;
}
- rc = emac_init_rxch(priv, EMAC_DEF_RX_CH, priv->mac_addr);
- if (0 != rc) {
+ err = emac_init_rxch(priv, EMAC_DEF_RX_CH, priv->mac_addr);
+ if (err) {
dev_err(emac_dev, "DaVinci EMAC: emac_init_rxch() failed");
- return rc;
+ return err;
}

/* Request IRQ */
@@ -2414,11 +2414,17 @@ static int emac_dev_open(struct net_device *ndev)
while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k))) {
for (i = res->start; i <= res->end; i++) {
if (request_irq(i, emac_irq, IRQF_DISABLED,
- ndev->name, ndev))
+ ndev->name, ndev)) {
+ i--;
+ err = -EBUSY;
+ dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
goto rollback;
+ }
}
k++;
}
+ if (k == 0)
+ return -ENODEV;

/* Start/Enable EMAC hardware */
emac_hw_enable(priv);
@@ -2436,7 +2442,8 @@ static int emac_dev_open(struct net_device *ndev)

if (!priv->phydev) {
printk(KERN_ERR "%s: no PHY found\n", ndev->name);
- return -1;
+ err = -ENODEV;
+ goto phydev_error;
}

priv->phydev = phy_connect(ndev, dev_name(&priv->phydev->dev),
@@ -2445,7 +2452,8 @@ static int emac_dev_open(struct net_device *ndev)
if (IS_ERR(priv->phydev)) {
printk(KERN_ERR "%s: Could not attach to PHY\n",
ndev->name);
- return PTR_ERR(priv->phydev);
+ err = PTR_ERR(priv->phydev);
+ goto phydev_error;
}

priv->link = 0;
@@ -2456,7 +2464,7 @@ static int emac_dev_open(struct net_device *ndev)
"(mii_bus:phy_addr=%s, id=%x)\n", ndev->name,
priv->phydev->drv->name, dev_name(&priv->phydev->dev),
priv->phydev->phy_id);
- } else{
+ } else {
/* No PHY , fix the link, speed and duplex settings */
priv->link = 1;
priv->speed = SPEED_100;
@@ -2475,15 +2483,29 @@ static int emac_dev_open(struct net_device *ndev)

return 0;

+phydev_error:
+ while (k--) {
+ res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k);
+ if (res != NULL)
+ break;
+ dev_err(emac_dev, "Couldn't free irqs for resource %d.\n", k);
+ }
+ if (res == NULL)
+ return err;
+ i = res->end;
rollback:
-
- dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
-
- for (q = k; k >= 0; k--) {
- for (m = i; m >= res->start; m--)
- free_irq(m, ndev);
- res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
- m = res->end;
+ for (j = i; j >= res->start; j--)
+ free_irq(j, ndev);
+
+ while (k--) {
+ res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k);
+ if (res == NULL) {
+ dev_err(emac_dev, "Couldn't free irqs for resource %d.\n",
+ k);
+ continue;
+ }
+ for (j = res->end; j >= res->start; j--)
+ free_irq(j, ndev);
}
return -EBUSY;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/