`comedi_alloc_spriv()` allocates private storage for a comedi subdevice
and sets the `SRF_FREE_SPRIV` flag in the `runflags` member of the
subdevice to allow the private storage to be automatically freed when
the comedi device is being cleaned up. Unfortunately, the flag gets
clobbered by `do_cmd_ioctl()` which calls
`comedi_set_subdevice_runflags()` with a mask value `~0` and only the
`SRF_USER` and `SRF_RUNNING` flags set, all the other SRF flags being
cleared.
Change the calls to `comedi_set_subdevice_runflags()` that currently use
a mask value of `~0` to use a more relevant mask value. For
`do_cmd_ioctl()`, the relevant SRF flags are `SRF_USER`, `SRF_ERROR` and
`SRF_RUNNING`. (At one time, `SRF_RT` would be included in that set of
flags, but it is no longer used.) For `comedi_alloc_spriv()` replace
the call to `comedi_set_subdevice_runflags()` with a simple
OR-assignment to avoid unnecessary use of a spin-lock.
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 3.11.y
---
v2: Replaced call to `comedi_set_subdevice_runflags()` from
`comedi_alloc_spriv()` with a simple OR-assignment, as suggested by
Hartley S Sweeten.
Note: The first version of this patch was posted on 2013-07-05 but I
think it must have got lost in the driverdev-devel mailing list outage
around that time.
---
drivers/staging/comedi/comedi_fops.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 1636c7c..a3af469 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -543,7 +543,7 @@ void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size)
{
s->private = kzalloc(size, GFP_KERNEL);
if (s->private)
- comedi_set_subdevice_runflags(s, ~0, SRF_FREE_SPRIV);
+ s->runflags |= SRF_FREE_SPRIV;
return s->private;
}
EXPORT_SYMBOL_GPL(comedi_alloc_spriv);
@@ -1485,7 +1485,8 @@ static int do_cmd_ioctl(struct comedi_device *dev,
if (async->cmd.flags & TRIG_WAKE_EOS)
async->cb_mask |= COMEDI_CB_EOS;
- comedi_set_subdevice_runflags(s, ~0, SRF_USER | SRF_RUNNING);
+ comedi_set_subdevice_runflags(s, SRF_USER | SRF_ERROR | SRF_RUNNING,
+ SRF_USER | SRF_RUNNING);
/* set s->busy _after_ setting SRF_RUNNING flag to avoid race with
* comedi_read() or comedi_write() */
--
1.8.3.2
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