Re: [PATCH] 8250-men-mcb: fix error checking when get_num_ports returns -ENODEV

From: Michael Moese
Date: Mon Oct 14 2019 - 02:55:19 EST




On 14.10.19 00:00, Colin King wrote:
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The current checking for failure on the number of ports fails when
-ENODEV is returned from the call to get_num_ports. Fix this by making
num_ports and loop counter i signed rather than unsigned ints. Also
add check for num_ports being less than zero to check for -ve error
returns.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: e2fea54e4592 ("8250-men-mcb: add support for 16z025 and 16z057")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>

This looks more than reasonable to me, thanks.

Reviewed-by: Michael Moese <mmoese@xxxxxxx>

---
drivers/tty/serial/8250/8250_men_mcb.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c
index 02c5aff58a74..8df89e9cd254 100644
--- a/drivers/tty/serial/8250/8250_men_mcb.c
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -72,8 +72,8 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
{
struct serial_8250_men_mcb_data *data;
struct resource *mem;
- unsigned int num_ports;
- unsigned int i;
+ int num_ports;
+ int i;
void __iomem *membase;
mem = mcb_get_resource(mdev, IORESOURCE_MEM);
@@ -88,7 +88,7 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
dev_dbg(&mdev->dev, "found a 16z%03u with %u ports\n",
mdev->id, num_ports);
- if (num_ports == 0 || num_ports > 4) {
+ if (num_ports <= 0 || num_ports > 4) {
dev_err(&mdev->dev, "unexpected number of ports: %u\n",
num_ports);
return -ENODEV;
@@ -133,7 +133,7 @@ static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
static void serial_8250_men_mcb_remove(struct mcb_device *mdev)
{
- unsigned int num_ports, i;
+ int num_ports, i;
struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev);
if (!data)


--
Michael Moese <mmoese@xxxxxxx>
QA Engineer
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