net: ipa: don't proceed to out-of-bound write

GCC 12 seems upset that we check ipa_irq against array bound
but then proceed, anyway:

drivers/net/ipa/ipa_interrupt.c: In function ‘ipa_interrupt_add’:
drivers/net/ipa/ipa_interrupt.c:196:27: warning: array subscript 30 is above array bounds of ‘void (*[30])(struct ipa *, enum ipa_irq_id)’ [-Warray-bounds]
  196 |         interrupt->handler[ipa_irq] = handler;
      |         ~~~~~~~~~~~~~~~~~~^~~~~~~~~
drivers/net/ipa/ipa_interrupt.c:42:27: note: while referencing ‘handler’
   42 |         ipa_irq_handler_t handler[IPA_IRQ_COUNT];
      |                           ^~~~~~~

Reviewed-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220519004417.2109886-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ipa/ipa_interrupt.c b/drivers/net/ipa/ipa_interrupt.c
index b35170a..307bed2 100644 (file)
--- a/drivers/net/ipa/ipa_interrupt.c
+++ b/drivers/net/ipa/ipa_interrupt.c
@@ -191,7 +191,8 @@ void ipa_interrupt_add(struct ipa_interrupt *interrupt,
        struct ipa *ipa = interrupt->ipa;
        u32 offset;
 
-       WARN_ON(ipa_irq >= IPA_IRQ_COUNT);
+       if (WARN_ON(ipa_irq >= IPA_IRQ_COUNT))
+               return;
 
        interrupt->handler[ipa_irq] = handler;
 
@@ -208,7 +209,8 @@ ipa_interrupt_remove(struct ipa_interrupt *interrupt, enum ipa_irq_id ipa_irq)
        struct ipa *ipa = interrupt->ipa;
        u32 offset;
 
-       WARN_ON(ipa_irq >= IPA_IRQ_COUNT);
+       if (WARN_ON(ipa_irq >= IPA_IRQ_COUNT))
+               return;
 
        /* Update the IPA interrupt mask to disable it */
        interrupt->enabled &= ~BIT(ipa_irq);