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authorTrent Piepho <xyzzy@speakeasy.org>2006-03-30 15:53:32 -0300
committerMauro Carvalho Chehab <mchehab@infradead.org>2006-04-02 04:56:01 -0300
commit5e85bd057f0cb29881e3d55d29f48bb55bd2f450 (patch)
tree7d1e582b25710d70487d1dc59e150b387a58c919 /drivers/media
parent2f03ee8e6bd7c6f40a1a0583662308e002d357da (diff)
V4L/DVB (3672): Fix memory leak in dvr open
The dvr device could be opened multiple times simultaneously in O_RDONLY mode. Each open after the first would allocate a new dvr buffer (1880 KB) and leak the old buffer. The first close would de-allocate the dvr buffer and cause all other open dvrs to stop working. This patch allows only a single O_RDONLY open of the drv device, as per the API specification. Multiple O_WRONLY opens are still allowed and don't appear to cause any problems. Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/dvb/dvb-core/dmxdev.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c
index 09e96e9ddbd..04578df3f24 100644
--- a/drivers/media/dvb/dvb-core/dmxdev.c
+++ b/drivers/media/dvb/dvb-core/dmxdev.c
@@ -141,12 +141,18 @@ static int dvb_dvr_open(struct inode *inode, struct file *file)
}
if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
- void *mem = vmalloc(DVR_BUFFER_SIZE);
+ void *mem;
+ if (!dvbdev->readers) {
+ mutex_unlock(&dmxdev->mutex);
+ return -EBUSY;
+ }
+ mem = vmalloc(DVR_BUFFER_SIZE);
if (!mem) {
mutex_unlock(&dmxdev->mutex);
return -ENOMEM;
}
dvb_ringbuffer_init(&dmxdev->dvr_buffer, mem, DVR_BUFFER_SIZE);
+ dvbdev->readers--;
}
if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
@@ -184,6 +190,7 @@ static int dvb_dvr_release(struct inode *inode, struct file *file)
dmxdev->dvr_orig_fe);
}
if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
+ dvbdev->readers++;
if (dmxdev->dvr_buffer.data) {
void *mem = dmxdev->dvr_buffer.data;
mb();
@@ -1029,8 +1036,7 @@ static struct file_operations dvb_dvr_fops = {
static struct dvb_device dvbdev_dvr = {
.priv = NULL,
- .users = 1,
- .writers = 1,
+ .readers = 1,
.fops = &dvb_dvr_fops
};