[PATCH] v4l2-ioctl: Don't assume file-private_data always points to a v4l2_fh
Commit efbceecd4522a41b8442c6b4f68b4508d57d1ccf, adds a number of helper functions for ctrl related ioctls to v4l2-ioctl.c, these helpers assume that if file-private_data != NULL, it points to a v4l2_fh, which is only the case for drivers which actually use v4l2_fh. This breaks for example bttv which use the filedata pointer for its own uses, and now all the ctrl ioctls try to use whatever its filedata points to as v4l2_fh and think it has a ctrl_handler, leading to: [ 142.499214] BUG: unable to handle kernel NULL pointer dereference at 0021 [ 142.499270] IP: [a01cb959] v4l2_queryctrl+0x29/0x230 [videodev] [ 142.514649] [a01c7a77] v4l_queryctrl+0x47/0x90 [videodev] [ 142.517417] [a01c58b1] __video_do_ioctl+0x2c1/0x420 [videodev] [ 142.520116] [a01c7ee6] video_usercopy+0x1a6/0x470 [videodev] ... This patch adds the missing test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) tests to the ctrl ioctl helpers v4l2_fh paths, fixing the issues with for example the bttv driver. Signed-off-by: Hans de Goede hdego...@redhat.com --- drivers/media/video/v4l2-ioctl.c | 21 ++--- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c index 70e0efb..3c498b2 100644 --- a/drivers/media/video/v4l2-ioctl.c +++ b/drivers/media/video/v4l2-ioctl.c @@ -1488,7 +1488,8 @@ static int v4l_queryctrl(const struct v4l2_ioctl_ops *ops, struct v4l2_queryctrl *p = arg; struct v4l2_fh *vfh = fh; - if (vfh vfh-ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) + vfh vfh-ctrl_handler) return v4l2_queryctrl(vfh-ctrl_handler, p); if (vfd-ctrl_handler) return v4l2_queryctrl(vfd-ctrl_handler, p); @@ -1504,7 +1505,8 @@ static int v4l_querymenu(const struct v4l2_ioctl_ops *ops, struct v4l2_querymenu *p = arg; struct v4l2_fh *vfh = fh; - if (vfh vfh-ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) + vfh vfh-ctrl_handler) return v4l2_querymenu(vfh-ctrl_handler, p); if (vfd-ctrl_handler) return v4l2_querymenu(vfd-ctrl_handler, p); @@ -1522,7 +1524,8 @@ static int v4l_g_ctrl(const struct v4l2_ioctl_ops *ops, struct v4l2_ext_controls ctrls; struct v4l2_ext_control ctrl; - if (vfh vfh-ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) + vfh vfh-ctrl_handler) return v4l2_g_ctrl(vfh-ctrl_handler, p); if (vfd-ctrl_handler) return v4l2_g_ctrl(vfd-ctrl_handler, p); @@ -1555,7 +1558,8 @@ static int v4l_s_ctrl(const struct v4l2_ioctl_ops *ops, struct v4l2_ext_controls ctrls; struct v4l2_ext_control ctrl; - if (vfh vfh-ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) + vfh vfh-ctrl_handler) return v4l2_s_ctrl(vfh, vfh-ctrl_handler, p); if (vfd-ctrl_handler) return v4l2_s_ctrl(NULL, vfd-ctrl_handler, p); @@ -1582,7 +1586,8 @@ static int v4l_g_ext_ctrls(const struct v4l2_ioctl_ops *ops, struct v4l2_fh *vfh = fh; p-error_idx = p-count; - if (vfh vfh-ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) + vfh vfh-ctrl_handler) return v4l2_g_ext_ctrls(vfh-ctrl_handler, p); if (vfd-ctrl_handler) return v4l2_g_ext_ctrls(vfd-ctrl_handler, p); @@ -1600,7 +1605,8 @@ static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops *ops, struct v4l2_fh *vfh = fh; p-error_idx = p-count; - if (vfh vfh-ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) + vfh vfh-ctrl_handler) return v4l2_s_ext_ctrls(vfh, vfh-ctrl_handler, p); if (vfd-ctrl_handler) return v4l2_s_ext_ctrls(NULL, vfd-ctrl_handler, p); @@ -1618,7 +1624,8 @@ static int v4l_try_ext_ctrls(const struct v4l2_ioctl_ops *ops, struct v4l2_fh *vfh = fh; p-error_idx = p-count; - if (vfh vfh-ctrl_handler) + if (test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) + vfh vfh-ctrl_handler) return v4l2_try_ext_ctrls(vfh-ctrl_handler, p); if (vfd-ctrl_handler) return v4l2_try_ext_ctrls(vfd-ctrl_handler, p); -- 1.7.10.4 -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] v4l2-ioctl: Don't assume file-private_data always points to a v4l2_fh
On Sat July 7 2012 20:46:21 Hans de Goede wrote:
Commit efbceecd4522a41b8442c6b4f68b4508d57d1ccf, adds a number of helper
functions for ctrl related ioctls to v4l2-ioctl.c, these helpers assume that
if file-private_data != NULL, it points to a v4l2_fh, which is only the case
for drivers which actually use v4l2_fh.
This breaks for example bttv which use the filedata pointer for its own
uses,
and now all the ctrl ioctls try to use whatever its filedata points to as
v4l2_fh and think it has a ctrl_handler, leading to:
[ 142.499214] BUG: unable to handle kernel NULL pointer dereference at
0021
[ 142.499270] IP: [a01cb959] v4l2_queryctrl+0x29/0x230 [videodev]
[ 142.514649] [a01c7a77] v4l_queryctrl+0x47/0x90 [videodev]
[ 142.517417] [a01c58b1] __video_do_ioctl+0x2c1/0x420 [videodev]
[ 142.520116] [a01c7ee6] video_usercopy+0x1a6/0x470 [videodev]
...
This patch adds the missing test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) tests
to the ctrl ioctl helpers v4l2_fh paths, fixing the issues with for example
the bttv driver.
Urgh, I didn't test with a 'old' driver. Thanks for catching this. But I would
prefer a simpler patch (although effectively the same) like this:
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index 70e0efb..bbcb4f6 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -1486,7 +1486,7 @@ static int v4l_queryctrl(const struct v4l2_ioctl_ops *ops,
{
struct video_device *vfd = video_devdata(file);
struct v4l2_queryctrl *p = arg;
- struct v4l2_fh *vfh = fh;
+ struct v4l2_fh *vfh = test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) ? fh
: NULL;
if (vfh vfh-ctrl_handler)
return v4l2_queryctrl(vfh-ctrl_handler, p);
@@ -1502,7 +1502,7 @@ static int v4l_querymenu(const struct v4l2_ioctl_ops *ops,
{
struct video_device *vfd = video_devdata(file);
struct v4l2_querymenu *p = arg;
- struct v4l2_fh *vfh = fh;
+ struct v4l2_fh *vfh = test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) ? fh
: NULL;
if (vfh vfh-ctrl_handler)
return v4l2_querymenu(vfh-ctrl_handler, p);
@@ -1518,7 +1518,7 @@ static int v4l_g_ctrl(const struct v4l2_ioctl_ops *ops,
{
struct video_device *vfd = video_devdata(file);
struct v4l2_control *p = arg;
- struct v4l2_fh *vfh = fh;
+ struct v4l2_fh *vfh = test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) ? fh
: NULL;
struct v4l2_ext_controls ctrls;
struct v4l2_ext_control ctrl;
@@ -1551,7 +1551,7 @@ static int v4l_s_ctrl(const struct v4l2_ioctl_ops *ops,
{
struct video_device *vfd = video_devdata(file);
struct v4l2_control *p = arg;
- struct v4l2_fh *vfh = fh;
+ struct v4l2_fh *vfh = test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) ? fh
: NULL;
struct v4l2_ext_controls ctrls;
struct v4l2_ext_control ctrl;
@@ -1579,7 +1579,7 @@ static int v4l_g_ext_ctrls(const struct v4l2_ioctl_ops
*ops,
{
struct video_device *vfd = video_devdata(file);
struct v4l2_ext_controls *p = arg;
- struct v4l2_fh *vfh = fh;
+ struct v4l2_fh *vfh = test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) ? fh
: NULL;
p-error_idx = p-count;
if (vfh vfh-ctrl_handler)
@@ -1597,7 +1597,7 @@ static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops
*ops,
{
struct video_device *vfd = video_devdata(file);
struct v4l2_ext_controls *p = arg;
- struct v4l2_fh *vfh = fh;
+ struct v4l2_fh *vfh = test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) ? fh
: NULL;
p-error_idx = p-count;
if (vfh vfh-ctrl_handler)
@@ -1615,7 +1615,7 @@ static int v4l_try_ext_ctrls(const struct v4l2_ioctl_ops
*ops,
{
struct video_device *vfd = video_devdata(file);
struct v4l2_ext_controls *p = arg;
- struct v4l2_fh *vfh = fh;
+ struct v4l2_fh *vfh = test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) ? fh
: NULL;
p-error_idx = p-count;
if (vfh vfh-ctrl_handler)
Regards,
Hans
Signed-off-by: Hans de Goede hdego...@redhat.com
---
drivers/media/video/v4l2-ioctl.c | 21 ++---
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/drivers/media/video/v4l2-ioctl.c
b/drivers/media/video/v4l2-ioctl.c
index 70e0efb..3c498b2 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -1488,7 +1488,8 @@ static int v4l_queryctrl(const struct v4l2_ioctl_ops
*ops,
struct v4l2_queryctrl *p = arg;
struct v4l2_fh *vfh = fh;
- if (vfh vfh-ctrl_handler)
+ if (test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags)
+ vfh vfh-ctrl_handler)
return v4l2_queryctrl(vfh-ctrl_handler, p);
if (vfd-ctrl_handler)
return v4l2_queryctrl(vfd-ctrl_handler, p);
@@ -1504,7 +1505,8 @@ static int v4l_querymenu(const struct
Re: [PATCH] v4l2-ioctl: Don't assume file-private_data always points to a v4l2_fh
Hi,
On 07/07/2012 09:11 PM, Hans Verkuil wrote:
On Sat July 7 2012 20:46:21 Hans de Goede wrote:
Commit efbceecd4522a41b8442c6b4f68b4508d57d1ccf, adds a number of helper
functions for ctrl related ioctls to v4l2-ioctl.c, these helpers assume that
if file-private_data != NULL, it points to a v4l2_fh, which is only the case
for drivers which actually use v4l2_fh.
This breaks for example bttv which use the filedata pointer for its own uses,
and now all the ctrl ioctls try to use whatever its filedata points to as
v4l2_fh and think it has a ctrl_handler, leading to:
[ 142.499214] BUG: unable to handle kernel NULL pointer dereference at
0021
[ 142.499270] IP: [a01cb959] v4l2_queryctrl+0x29/0x230 [videodev]
[ 142.514649] [a01c7a77] v4l_queryctrl+0x47/0x90 [videodev]
[ 142.517417] [a01c58b1] __video_do_ioctl+0x2c1/0x420 [videodev]
[ 142.520116] [a01c7ee6] video_usercopy+0x1a6/0x470 [videodev]
...
This patch adds the missing test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) tests
to the ctrl ioctl helpers v4l2_fh paths, fixing the issues with for example
the bttv driver.
Urgh, I didn't test with a 'old' driver. Thanks for catching this. But I would
prefer a simpler patch (although effectively the same) like this:
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index 70e0efb..bbcb4f6 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -1486,7 +1486,7 @@ static int v4l_queryctrl(const struct v4l2_ioctl_ops *ops,
{
struct video_device *vfd = video_devdata(file);
struct v4l2_queryctrl *p = arg;
- struct v4l2_fh *vfh = fh;
+ struct v4l2_fh *vfh = test_bit(V4L2_FL_USES_V4L2_FH, vfd-flags) ? fh
: NULL;
if (vfh vfh-ctrl_handler)
return v4l2_queryctrl(vfh-ctrl_handler, p);
snip
I agree that that is better, so I've added that version to my tree now, for
which I
expect / hope to send a pullreq later tonight.
Regards,
Hans
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