Re: [PATCH] MIPS: SGI-IP27: Fix use of unchecked pointer in shutdown_bridge_irq

[Mukesh Ojha]

On 3/28/2019 7:07 PM, Thomas Bogendoerfer wrote:

smatch complaint:

     arch/mips/sgi-ip27/ip27-irq.c:123 shutdown_bridge_irq()
     warn: variable dereferenced before check 'hd' (see line 121)

Fix it by removing local variable and use hd->pin directly.

Fixes: 69a07a41d908 ("MIPS: SGI-IP27: rework HUB interrupts")
Reported-by: Dan Carpenter <dan.carpen...@oracle.com>
Signed-off-by: Thomas Bogendoerfer <tbogendoer...@suse.de>

Reviewed-by: Mukesh Ojha <mo...@codeaurora.org>

-Mukesh

---
  arch/mips/sgi-ip27/ip27-irq.c | 3 +--
  1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/mips/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index 710a59764b01..a32f843cdbe0 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/arch/mips/sgi-ip27/ip27-irq.c
@@ -118,7 +118,6 @@ static void shutdown_bridge_irq(struct irq_data *d)
  {
        struct hub_irq_data *hd = irq_data_get_irq_chip_data(d);
        struct bridge_controller *bc;
-       int pin = hd->pin;

if (!hd)

                return;
@@ -126,7 +125,7 @@ static void shutdown_bridge_irq(struct irq_data *d)
        disable_hub_irq(d);

bc = hd->bc;

-       bridge_clr(bc, b_int_enable, (1 << pin));
+       bridge_clr(bc, b_int_enable, (1 << hd->pin));
        bridge_read(bc, b_wid_tflush);
  }