staging: kpc2000: fix integer overflow with left shifts

Currently there are several left shifts that are assigned to 64 bit
unsigned longs where a signed int 1 is being shifted, resulting in
an integer overflow.  Fix this bit using the BIT_ULL macro to perform
a 64 bit shift.  Also clean up an overly long statement.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: 7dc7967fc39a ("staging: kpc2000: add initial set of Daktronics drivers")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/kpc2000/kpc2000/cell_probe.c b/drivers/staging/kpc2000/kpc2000/cell_probe.c
index 138d16bcf6e1cf0b300a18f29cb3766252fb49c9..c124a836db27e04c157286a68bc35497131619d8 100644 (file)
--- a/drivers/staging/kpc2000/kpc2000/cell_probe.c
+++ b/drivers/staging/kpc2000/kpc2000/cell_probe.c
@@ -238,7 +238,7 @@ int  kp2000_check_uio_irq(struct kp2000_device *pcard, u32 irq_num)
 {
        u64 interrupt_active   =  readq(pcard->sysinfo_regs_base + REG_INTERRUPT_ACTIVE);
        u64 interrupt_mask_inv = ~readq(pcard->sysinfo_regs_base + REG_INTERRUPT_MASK);
-       u64 irq_check_mask = (1 << irq_num);
+       u64 irq_check_mask = BIT_ULL(irq_num);
 
        if (interrupt_active & irq_check_mask) { // if it's active (interrupt pending)
                if (interrupt_mask_inv & irq_check_mask) {    // and if it's not masked off
@@ -257,7 +257,9 @@ irqreturn_t  kuio_handler(int irq, struct uio_info *uioinfo)
                return IRQ_NONE;
 
        if (kp2000_check_uio_irq(kudev->pcard, kudev->cte.irq_base_num)) {
-               writeq((1 << kudev->cte.irq_base_num), kudev->pcard->sysinfo_regs_base + REG_INTERRUPT_ACTIVE); // Clear the active flag
+               /* Clear the active flag */
+               writeq(BIT_ULL(kudev->cte.irq_base_num),
+                      kudev->pcard->sysinfo_regs_base + REG_INTERRUPT_ACTIVE);
                return IRQ_HANDLED;
        }
        return IRQ_NONE;
@@ -273,9 +275,9 @@ int kuio_irqcontrol(struct uio_info *uioinfo, s32 irq_on)
        mutex_lock(&pcard->sem);
        mask = readq(pcard->sysinfo_regs_base + REG_INTERRUPT_MASK);
        if (irq_on)
-               mask &= ~(1 << (kudev->cte.irq_base_num));
+               mask &= ~(BIT_ULL(kudev->cte.irq_base_num));
        else
-               mask |= (1 << (kudev->cte.irq_base_num));
+               mask |= BIT_ULL(kudev->cte.irq_base_num);
        writeq(mask, pcard->sysinfo_regs_base + REG_INTERRUPT_MASK);
        mutex_unlock(&pcard->sem);