diff options
| author | Steven Toth <stoth@kernellabs.com> | 2010-07-31 15:11:59 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2010-10-21 07:54:53 -0200 |
| commit | 46eeb8dd30d3651e6ea55c2e60594206cd591d79 (patch) | |
| tree | ec3d2d34b7f6e7c68aadec8aca8091e213e274c4 /drivers/media/video/saa7164/saa7164-encoder.c | |
| parent | 58acca1056434dbbbcb3f1aacd759f1039a3169d (diff) | |
| download | lwn-46eeb8dd30d3651e6ea55c2e60594206cd591d79.tar.gz lwn-46eeb8dd30d3651e6ea55c2e60594206cd591d79.zip | |
[media] saa7164: add guard bytes around critical buffers to detect failure
If the guard bytes are trampled then we have a memory related problem.
Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/saa7164/saa7164-encoder.c')
| -rw-r--r-- | drivers/media/video/saa7164/saa7164-encoder.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/media/video/saa7164/saa7164-encoder.c b/drivers/media/video/saa7164/saa7164-encoder.c index 5f73ceded31b..c61907d0efb9 100644 --- a/drivers/media/video/saa7164/saa7164-encoder.c +++ b/drivers/media/video/saa7164/saa7164-encoder.c @@ -1038,14 +1038,18 @@ static ssize_t fops_read(struct file *file, char __user *buffer, saa7164_histogram_update(&port->read_interval, port->last_read_msecs_diff); - if (*pos) + if (*pos) { + printk(KERN_ERR "%s() ESPIPE\n", __func__); return -ESPIPE; + } if (atomic_cmpxchg(&fh->v4l_reading, 0, 1) == 0) { if (atomic_inc_return(&port->v4l_reader_count) == 1) { - if (saa7164_encoder_initialize(port) < 0) + if (saa7164_encoder_initialize(port) < 0) { + printk(KERN_ERR "%s() EINVAL\n", __func__); return -EINVAL; + } saa7164_encoder_start_streaming(port); msleep(200); @@ -1056,6 +1060,7 @@ static ssize_t fops_read(struct file *file, char __user *buffer, if ((file->f_flags & O_NONBLOCK) == 0) { if (wait_event_interruptible(port->wait_read, saa7164_enc_next_buf(port))) { + printk(KERN_ERR "%s() ERESTARTSYS\n", __func__); return -ERESTARTSYS; } } @@ -1077,8 +1082,10 @@ static ssize_t fops_read(struct file *file, char __user *buffer, if (copy_to_user(buffer, p, cnt)) { printk(KERN_ERR "%s() copy_to_user failed\n", __func__); - if (!ret) + if (!ret) { + printk(KERN_ERR "%s() EFAULT\n", __func__); ret = -EFAULT; + } goto err; } @@ -1087,6 +1094,10 @@ static ssize_t fops_read(struct file *file, char __user *buffer, buffer += cnt; ret += cnt; + if (ubuf->pos > ubuf->actual_size) { + printk(KERN_ERR "read() pos > actual, huh?\n"); + } + if (ubuf->pos == ubuf->actual_size) { /* finished with current buffer, take next buffer */ @@ -1109,8 +1120,10 @@ static ssize_t fops_read(struct file *file, char __user *buffer, } } err: - if (!ret && !ubuf) + if (!ret && !ubuf) { + printk(KERN_ERR "%s() EAGAIN\n", __func__); ret = -EAGAIN; + } return ret; } |