From 0b1221a36ca53dca5992caf6b37f67c98bb4e431 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Wed, 24 Aug 2016 07:06:58 +0200 Subject: [PATCH] serial: vt8500_serial: Fix a parameter of find_first_zero_bit. 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 Reviewed-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman --- 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; } -- 2.34.1