On 21/12/24 15:13, Greg KH wrote:
On Sat, Dec 21, 2024 at 10:25:41AM +0100, Greg KH wrote:
On Sat, Dec 21, 2024 at 02:41:25PM +0530, Nihar Chaithanya wrote:
The if condition in cb7210_init_module() would always fail as
the value of err is constantly 0. The function
cb_pcmcia_init_module() can be refactored into a single line,
and can be replaced entirely with pcmcia_register_driver().
Replace redundant cb_pcmcia_init_module() with
pcmcia_register_driver() which returns appropriate error code if
it fails. Handle the error if it fails and print the debug message.
This issue was reported by Coverity Scan.
Report:
CID 1635894: (#1 of 1): 'Constant' variable guards dead code (DEADCODE)
dead_error_line: Execution cannot reach this statement: return -1;.
Signed-off-by: Nihar Chaithanya <niharchaithanya@xxxxxxxxx>
---
v1 --> v2: Replaced the redundant cb_pcmcia_init_module() with
pcmcia_register_driver().
drivers/staging/gpib/cb7210/cb7210.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/gpib/cb7210/cb7210.c b/drivers/staging/gpib/cb7210/cb7210.c
index 63df7f3eb3f3..abd6632d8448 100644
--- a/drivers/staging/gpib/cb7210/cb7210.c
+++ b/drivers/staging/gpib/cb7210/cb7210.c
@@ -1351,12 +1351,6 @@ static struct pcmcia_driver cb_gpib_cs_driver = {
.resume = cb_gpib_resume,
};
-int cb_pcmcia_init_module(void)
-{
- pcmcia_register_driver(&cb_gpib_cs_driver);
- return 0;
-}
-
void cb_pcmcia_cleanup_module(void)
{
DEBUG(0, "cb_gpib_cs: unloading\n");
@@ -1526,11 +1520,12 @@ static int __init cb7210_init_module(void)
gpib_register_driver(&cb_pcmcia_interface, THIS_MODULE);
gpib_register_driver(&cb_pcmcia_accel_interface, THIS_MODULE);
gpib_register_driver(&cb_pcmcia_unaccel_interface, THIS_MODULE);
- err += cb_pcmcia_init_module();
+ err = pcmcia_register_driver(&cb_gpib_cs_driver);
#endif
- if (err)
+ if (err) {
+ pr_err("cb7210: registering PCMCIA driver with the bus core failed\n");
return -1;
Not your issue, but "-1" is not a valid error number, shouldn't this be
returning a real error (i.e. the one that was returned?)
And err += is crazy, thanks for removing that, BUT you forgot to unwind
the previous functions so now if pcmcia_register_driver() fails, you
have a semi-registered system and then the module will unload (as init
fails) and bad things will happen :(
So I need be unregistering the driver if the pcmcia_register_driver() fails
right?
So you kind of just made the code worse overall, not better, which
really isn't a good idea for a "bugfix" that covertity was trying to
point out.
And (this is taking you down a path that is much larger than you
expected to just fix this one issue, sorry), it looks like
gpib_register_driver() can fail, so it MUST return an error value so you
can properly unwind from it. So that too needs to be fixed up here
(also minor nit, gpib_register_driver() should not be calling pr_info(),
but that's a different issue.)
Yes Greg, gpib_register_driver() should be returning -ENOMEM if it fails,
thank you for pointing it out, I'll change the gpib code wherever the
drivers are registered, I'll send the patch as soon as I can.
In all, there are loads of tiny things like this to fix up in the gpib
code, which is great, have fun!
yes, I am happy to contribute.
thanks,
greg k-h
thank you,
Nihar
