ata: pata_parport: add driver (PARIDE replacement)

Hello Ondrej Zary,

The patch 246a1c4c6b7f: "ata: pata_parport: add driver (PARIDE replacement)" from Jan 23, 2023, leads to the following Smatch static checker warning:

	drivers/ata/pata_parport/pata_parport.c:445 pi_init_one()
	warn: unsigned 'pi->dev.id' is never less than zero.

drivers/ata/pata_parport/pata_parport.c

    418 static struct pi_adapter *pi_init_one(struct parport *parport,
    419                         struct pi_protocol *pr, int mode, int unit, int delay)
    420 {
    421         struct pardev_cb par_cb = { };
    422         char scratch[512];
    423         const struct ata_port_info *ppi[] = { &pata_parport_port_info };
    424         struct ata_host *host;
    425         struct pi_adapter *pi;
    426         struct pi_device_match match = { .parport = parport, .proto = pr };
    427 
    428         /*
    429          * Abort if there's a device already registered on the same parport
    430          * using the same protocol.
    431          */
    432         if (bus_for_each_dev(&pata_parport_bus_type, NULL, &match, pi_find_dev))
    433                 return NULL;
    434 
    435         pi = kzalloc(sizeof(struct pi_adapter), GFP_KERNEL);
    436         if (!pi)
    437                 return NULL;
    438 
    439         /* set up pi->dev before pi_probe_unit() so it can use dev_printk() */
    440         pi->dev.parent = &pata_parport_bus;
    441         pi->dev.bus = &pata_parport_bus_type;
    442         pi->dev.driver = &pr->driver;
    443         pi->dev.release = pata_parport_dev_release;
    444         pi->dev.id = ida_alloc(&pata_parport_bus_dev_ids, GFP_KERNEL);
--> 445         if (pi->dev.id < 0)
                    ^^^^^^^^^^^^^^

pi->dev.id is a u32.

    446                 return NULL; /* pata_parport_dev_release will do kfree(pi) */
    447         dev_set_name(&pi->dev, "pata_parport.%u", pi->dev.id);
    448         if (device_register(&pi->dev)) {
    449                 put_device(&pi->dev);
    450                 goto out_ida_free;
    451         }

regards,
dan carpenter

pi->dev.id is unsigned so error checking of ida_alloc return value does not work. Fix it.

---
 drivers/ata/pata_parport/pata_parport.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

index 9e8ad93d7e59..294a266a0dda 100644
@@ -424,6 +424,7 @@ static struct pi_adapter *pi_init_one(struct parport *parport,
 	struct ata_host *host;
 	struct pi_adapter *pi;
 	struct pi_device_match match = { .parport = parport, .proto = pr };
+	int id;
 
 	/*
 	 * Abort if there's a device already registered on the same parport

@@ -441,9 +442,10 @@ static struct pi_adapter *pi_init_one(struct parport *parport,
 	pi->dev.bus = &pata_parport_bus_type;
 	pi->dev.driver = &pr->driver;
 	pi->dev.release = pata_parport_dev_release;
-	pi->dev.id = ida_alloc(&pata_parport_bus_dev_ids, GFP_KERNEL);
-	if (pi->dev.id < 0)
+	id = ida_alloc(&pata_parport_bus_dev_ids, GFP_KERNEL);
+	if (id < 0)
 		return NULL; /* pata_parport_dev_release will do kfree(pi) */
+	pi->dev.id = id;
 	dev_set_name(&pi->dev, "pata_parport.%u", pi->dev.id);
 	if (device_register(&pi->dev)) {
 		put_device(&pi->dev);

Ondrej Zary

Hello!

[...]

MBR, Sergey

Applied. Thanks !

Damien Le Moal
Western Digital Research