The most common place to find POLL... bitmaps: return values
of ->poll() and its subsystem counterparts.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Drop the FSF's postal address from the source code files that typically
contain mostly the license text. Of the 628 removed instances, 578 are
outdated.
The patch has been created with the following command without manual edits:
git grep -l "675 Mass Ave\|59 Temple Place\|51 Franklin St" -- \
drivers/media/ include/media|while read i; do i=$i perl -e '
open(F,"< $ENV{i}");
$a=join("", <F>);
$a =~ s/[ \t]*\*\n.*You should.*\n.*along with.*\n.*(\n.*USA.*$)?\n//m
&& $a =~ s/(^.*)Or, (point your browser to) /$1To obtain the license, $2\n$1/m;
close(F);
open(F, "> $ENV{i}");
print F $a;
close(F);'; done
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Fix this warning:
Documentation/media/kapi/mc-core.rst:97: WARNING: c:func reference target not found: media_devnode_release
The media_device_release() is a function internal to media-devnode.c,
and not exported elsewhere. So, we can't cross-reference it here.
Make it explicit at the documentation.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are several issues on the documentation:
- the media.h header were not properly referenced;
- verbatim expressions were not properly marked as such;
- struct member references were wrong;
- some notes were not using the right markup;
- a comment that were moved to the kernel-doc markup were
duplicated as a comment inside the struct media_entity;
- some args were not pointing to the struct they're using;
- macros weren't documented.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Two parameters were documented with a wrong name, and a struct
device pointer description was missing.
That caused the following warnings, when building documentation:
include/media/media-devnode.h:102: warning: No description found for parameter 'media_dev'
include/media/media-devnode.h:126: warning: No description found for parameter 'mdev'
include/media/media-devnode.h:126: warning: Excess function parameter 'media_dev' description in 'media_devnode_register'
Rename the description, to match the function parameter and fix
Documentation.
No funcional changes.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Media devnode open/ioctl could be in progress when media device unregister
is initiated. System calls and ioctls check media device registered status
at the beginning, however, there is a window where unregister could be in
progress without changing the media devnode status to unregistered.
process 1 process 2
fd = open(/dev/media0)
media_devnode_is_registered()
(returns true here)
media_device_unregister()
(unregister is in progress
and devnode isn't
unregistered yet)
...
ioctl(fd, ...)
__media_ioctl()
media_devnode_is_registered()
(returns true here)
...
media_devnode_unregister()
...
(driver releases the media device
memory)
media_device_ioctl()
(By this point
devnode->media_dev does not
point to allocated memory.
use-after free in in mutex_lock_nested)
BUG: KASAN: use-after-free in mutex_lock_nested+0x79c/0x800 at addr
ffff8801ebe914f0
Fix it by clearing register bit when unregister starts to avoid the race.
process 1 process 2
fd = open(/dev/media0)
media_devnode_is_registered()
(could return true here)
media_device_unregister()
(clear the register bit,
then start unregister.)
...
ioctl(fd, ...)
__media_ioctl()
media_devnode_is_registered()
(return false here, ioctl
returns I/O error, and
will not access media
device memory)
...
media_devnode_unregister()
...
(driver releases the media device
memory)
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reported-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Tested-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
struct media_devnode is currently embedded at struct media_device.
While this works fine during normal usage, it leads to a race
condition during devnode unregister. the problem is that drivers
assume that, after calling media_device_unregister(), the struct
that contains media_device can be freed. This is not true, as it
can't be freed until userspace closes all opened /dev/media devnodes.
In other words, if the media devnode is still open, and media_device
gets freed, any call to an ioctl will make the core to try to access
struct media_device, with will cause an use-after-free and even GPF.
Fix this by dynamically allocating the struct media_devnode and only
freeing it when it is safe.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Along all media controller code, "mdev" is used to represent
a pointer to struct media_device, and "devnode" for a pointer
to struct media_devnode.
However, inside media-devnode.[ch], "mdev" is used to represent
a pointer to struct media_devnode.
This is very confusing and may lead to development errors.
So, let's change all occurrences at media-devnode.[ch] to
also use "devnode" for such pointers.
This patch doesn't make any functional changes.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There is one struct and two functions that were not documented.
Add the corresponding kernel-doc documentation for them.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
As we're using the headers file only for documentation, move the
two kernel-doc macros to the header, and fix it to avoid
warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Warning(.//include/media/media-devnode.h:80): No description found for parameter 'fops'
Warning(.//include/media/media-devnode.h:80): No description found for parameter 'dev'
Warning(.//include/media/media-devnode.h:80): No description found for parameter 'cdev'
Warning(.//include/media/media-devnode.h:80): No description found for parameter 'release'
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
mdev->fops->owner is actually the owner of the very same module which
implements media_device_register(), so it can't be unloaded anyway. Instead,
use THIS_MODULE through a macro as does video_register_device().
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
The media_devnode structure provides support for registering and
unregistering character devices using a dynamic major number. Reference
counting is handled internally, making device drivers easier to write
without having to solve the open/disconnect race condition issue over
and over again.
The code is based on video/v4l2-dev.c.
[mchehab@redhat.com: Remove linux/smp_lock.h include to not break compilation on bisect]
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Al Viro
Sakari Ailus
Mauro Carvalho Chehab
Shuah Khan
Mauro Carvalho Chehab
Sakari Ailus
Laurent Pinchart