The 2nd parameter of 'find_first_zero_bit' is the number of bits to search.
In this case, we are passing 'sizeof(vt8500_ports_in_use)'.
'vt8500_ports_in_use' is an 'unsigned long'. So the sizeof is likely to
return 4 on a 32 bits kernel.
A few lines below, we check if it is below VT8500_MAX_PORTS, which is 6.
It is likely that the number of bits in a long was expected here.
In order to fix it:
- use DECLARE_BITMAP when declaring the vt8500_ports_in_use
- use VT8500_MAX_PORTS as a maximum value when checking/setting bits in
this bitmap
- modify code now that 'vt8500_ports_in_use' has become a pointer
because of the use of DECLARE_BITMAP
It has been spotted by the following coccinelle script:
@@
expression ret, x;
@@
* ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...));
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
v2: - use of VT8500_MAX_PORTS instead of BITS_PER_LONG to better self
document the code
- declare vt8500_ports_in_use with DECLARE_BITMAP in order to self
document even better and to be foolproof should VT8500_MAX_PORTS
be changed one day
---
drivers/tty/serial/vt8500_serial.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index 23cfc5e16b45..6b85adce0ac9 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -118,7 +118,7 @@ struct vt8500_port {
* have been allocated as we can't use pdev->id in
* devicetree
*/
-static unsigned long vt8500_ports_in_use;
+static DECLARE_BITMAP(vt8500_ports_in_use, VT8500_MAX_PORTS);
static inline void vt8500_write(struct uart_port *port, unsigned int val,
unsigned int off)
@@ -663,15 +663,15 @@ static int vt8500_serial_probe(struct platform_device *pdev)
if (port < 0) {
/* calculate the port id */
- port = find_first_zero_bit(&vt8500_ports_in_use,
- sizeof(vt8500_ports_in_use));
+ port = find_first_zero_bit(vt8500_ports_in_use,
+ VT8500_MAX_PORTS);
}
if (port >= VT8500_MAX_PORTS)
return -ENODEV;
/* reserve the port id */
- if (test_and_set_bit(port, &vt8500_ports_in_use)) {
+ if (test_and_set_bit(port, vt8500_ports_in_use)) {
/* port already in use - shouldn't really happen */
return -EBUSY;
}
--
2.7.4
---
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
https://www.avast.com/antivirus
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
