re: staging: media: lirc: lirc_zilog.c: replace custom print macros with dev_* and pr_*

Dan Carpenter
2014-10-31T13:06:16Z

Hello Aya Mahfouz,

The patch be4aa8157c98: "staging: media: lirc: lirc_zilog.c: replace
custom print macros with dev_* and pr_*" from Oct 26, 2014, leads to
the following static checker warning:

drivers/staging/media/lirc/lirc_zilog.c:1340 close()
error: we previously assumed 'ir' could be null (see line 1339)

drivers/staging/media/lirc/lirc_zilog.c
1333 /* Close the IR device */
1334 static int close(struct inode *node, struct file *filep)
1335 {
1336 /* find our IR struct */
1337 struct IR *ir = filep->private_data;
1338
1339 if (ir == NULL) {
^^^^^^^^^^
1340 dev_err(ir->l.dev, "close: no private_data attached to the file!\n");
^^^^^^^^^

I suggest you just delete the error message. Can "ir" actually be NULL
here anyway?

1341 return -ENODEV;
1342 }
1343

drivers/staging/media/lirc/lirc_zilog.c:1636 ir_probe()
error: potential null dereference 'ir'. (kzalloc returns null)

drivers/staging/media/lirc/lirc_zilog.c
1614 dev_info(ir->l.dev, "IR unit on %s (i2c-%d) registered as lirc%d and ready\n",
1615 adap->name, adap->nr, ir->l.minor);
1616
1617 out_ok:
1618 if (rx != NULL)
1619 put_ir_rx(rx, true);
1620 if (tx != NULL)
1621 put_ir_tx(tx, true);
1622 put_ir_device(ir, true);
1623 dev_info(ir->l.dev, "probe of IR %s on %s (i2c-%d) done\n",
1624 tx_probe ? "Tx" : "Rx", adap->name, adap->nr);
1625 mutex_unlock(&ir_devices_lock);
1626 return 0;
1627
1628 out_put_xx:
1629 if (rx != NULL)
1630 put_ir_rx(rx, true);
^^^^^^^^^^^^^^^^^^^
Btw, I think this is a double free? On some paths we call put_ir_rx()
before the goto out_put_xx;.

1631 if (tx != NULL)
1632 put_ir_tx(tx, true);
1633 out_put_ir:
1634 put_ir_device(ir, true);
1635 out_no_ir:
1636 dev_err(ir->l.dev, "%s: probing IR %s on %s (i2c-%d) failed with %d\n",
^^^^^^^^^
Null dereference.

1637 __func__, tx_probe ? "Tx" : "Rx", adap->name, adap->nr,
1638 ret);
1639 mutex_unlock(&ir_devices_lock);
1640 return ret;
1641 }

regards,
dan carpenter