[PATCH] i386: handle a negative return value

The Coverity checker noted that bad things might happen if
find_isa_irq_apic() returned -1.

[akpm@osdl.org: add debugging checks]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 993150f206ed..7bfd6c3ec87d 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -2179,9 +2179,15 @@ static inline void unlock_ExtINT_logic(void)
         unsigned char save_control, save_freq_select;
 
         pin  = find_isa_irq_pin(8, mp_INT);
+        if (pin == -1) {
+                WARN_ON_ONCE(1);
+                return;
+        }
         apic = find_isa_irq_apic(8, mp_INT);
-        if (pin == -1)
+        if (apic == -1) {
+                WARN_ON_ONCE(1);
                 return;
+        }
 
         entry0 = ioapic_read_entry(apic, pin);
         clear_IO_APIC_pin(apic, pin);