linux-stable.git/drivers/media/media-devnode.c, branch master

media: move drivers/media/media-* to drivers/media/mc/mc-*

2019-05-28T16:15:46+00:00

It is really weird that the media controller sources are all top-level
in drivers/media. It is a bit of a left-over from long ago when most
media sources were all at the top-level. At some point we reorganized
the directory structure, but the media-*.c sources where never moved
to their own directory.

So create a new mc directory and move all sources there. Also rename
the prefix from media- to mc-.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: Clear devnode->media_dev holding media_devnode_lock

2019-04-22T15:24:33+00:00

Fix media_devnode_unregister() to clear devnode->media_dev while holding
media_devnode_lock. media_devnode_register()'s cdev_add_error handling
does this correctly.

Signed-off-by: Shuah Khan 
Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: media-devnode: fill in media chardev kobject to ease debugging

2019-03-19T17:21:16+00:00

The media chardev kobject has no name, which made it hard to
debug when kobject debugging is turned on.

Signed-off-by: Hans Verkuil 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Mauro Carvalho Chehab

MAINTAINERS & files: Canonize the e-mails I use at files

2018-05-04T10:21:06+00:00

From now on, I'll start using my @kernel.org as my development e-mail.

As such, let's remove the entries that point to the old
mchehab@s-opensource.com at MAINTAINERS file.

For the files written with a copyright with mchehab@s-opensource,
let's keep Samsung on their names, using mchehab+samsung@kernel.org,
in order to keep pointing to my employer, with sponsors the work.

For the files written before I join Samsung (on July, 4 2013),
let's just use mchehab@kernel.org.

For bug reports, we can simply point to just kernel.org, as
this will reach my mchehab+samsung inbox anyway.

Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Brian Warner 
Signed-off-by: Mauro Carvalho Chehab

vfs: do bulk POLL* -> EPOLL* replacement

2018-02-11T22:34:03+00:00

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro 
Signed-off-by: Linus Torvalds

media: annotate ->poll() instances

2017-11-27T21:20:06+00:00

Signed-off-by: Al Viro

media: utilize new cdev_device_add helper function

2017-03-21T05:44:33+00:00

Replace the open coded registration of the cdev and dev with the
new device_add_cdev() helper. The helper replaces a common pattern by
taking the proper reference against the parent device and adding both
the cdev and the device.

Signed-off-by: Logan Gunthorpe 
Acked-by: Hans Verkuil 
Signed-off-by: Greg Kroah-Hartman

[media] media: Drop FSF's postal address from the source code files

2017-01-27T13:38:09+00:00

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("", );
$a =~ s/[ \t]*\*\n.*You should.*\n.*along with.*\n.*(\n.*USA.*$)?\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

[media] media: fix media devnode ioctl/syscall and unregister race

2016-06-15T20:59:28+00:00

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 
Suggested-by: Sakari Ailus 
Reported-by: Mauro Carvalho Chehab 
Tested-by: Mauro Carvalho Chehab 
Signed-off-by: Mauro Carvalho Chehab

[media] media: fix use-after-free in cdev_put() when app exits after driver unbind

2016-06-15T20:58:06+00:00

When driver unbinds while media_ioctl is in progress, cdev_put() fails with
when app exits after driver unbinds.

Add devnode struct device kobj as the cdev parent kobject. cdev_add() gets
a reference to it and releases it in cdev_del() ensuring that the devnode
is not deallocated as long as the application has the device file open.

media_devnode_register() initializes the struct device kobj before calling
cdev_add(). media_devnode_unregister() does cdev_del() and then deletes the
device. devnode is released when the last reference to the struct device is
gone.

This problem is found on uvcvideo, em28xx, and au0828 drivers and fix has
been tested on all three.

kernel: [  193.599736] BUG: KASAN: use-after-free in cdev_put+0x4e/0x50
kernel: [  193.599745] Read of size 8 by task media_device_te/1851
kernel: [  193.599792] INFO: Allocated in __media_device_register+0x54
kernel: [  193.599951] INFO: Freed in media_devnode_release+0xa4/0xc0

kernel: [  193.601083] Call Trace:
kernel: [  193.601093]  [] dump_stack+0x67/0x94
kernel: [  193.601102]  [] print_trailer+0x112/0x1a0
kernel: [  193.601111]  [] object_err+0x34/0x40
kernel: [  193.601119]  [] kasan_report_error+0x224/0x530
kernel: [  193.601128]  [] ? kzfree+0x2d/0x40
kernel: [  193.601137]  [] ? kfree+0x1d2/0x1f0
kernel: [  193.601154]  [] ? cdev_put+0x4e/0x50
kernel: [  193.601162]  [] cdev_put+0x4e/0x50
kernel: [  193.601170]  [] __fput+0x52b/0x6c0
kernel: [  193.601179]  [] ? switch_task_namespaces+0x2a
kernel: [  193.601188]  [] ____fput+0xe/0x10
kernel: [  193.601196]  [] task_work_run+0x133/0x1f0
kernel: [  193.601204]  [] ? switch_task_namespaces+0x5e
kernel: [  193.601213]  [] do_exit+0x72c/0x2c20
kernel: [  193.601224]  [] ? release_task+0x1250/0x1250
-
-
-
kernel: [  193.601360]  [] ? exit_to_usermode_loop+0xe7
kernel: [  193.601368]  [] exit_to_usermode_loop+0x120
kernel: [  193.601376]  [] syscall_return_slowpath+0x16a
kernel: [  193.601386]  [] entry_SYSCALL_64_fastpath+0xa6

Signed-off-by: Shuah Khan 
Tested-by: Mauro Carvalho Chehab 
Signed-off-by: Mauro Carvalho Chehab