With the original code I observe
In function ‘__irq_to_desc’,
inlined from ‘route_irq_to_guest’ at arch/arm/irq.c:465:12:
arch/arm/irq.c:54:16: error: array subscript -2 is below array bounds of
‘irq_desc_t[32]’ {aka ‘struct irq_desc[32]’} [-Werror=array-bounds=]
54 | return &this_cpu(local_irq_desc)[irq];
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
which looks pretty bogus: How in the world does the compiler arrive at
-2 when compiling route_irq_to_guest()? Yet independent of that the
function's parameter wants to be of unsigned type anyway, as shown by
a vast majority of callers (others use plain int when they really mean
non-negative quantities). With that adjustment the code compiles fine
again.
Signed-off-by: Jan Beulich <jbeul...@suse.com>
---
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116519
--- a/xen/arch/arm/include/asm/irq.h
+++ b/xen/arch/arm/include/asm/irq.h
@@ -56,7 +56,7 @@ extern const unsigned int nr_irqs;
struct irq_desc;
struct irqaction;
-struct irq_desc *__irq_to_desc(int irq);
+struct irq_desc *__irq_to_desc(unsigned int irq);
#define irq_to_desc(irq) __irq_to_desc(irq)
--- unstable.orig/xen/arch/arm/irq.c 2024-06-28 15:56:44.000000000 +0200
+++ unstable/xen/arch/arm/irq.c 2024-08-28 15:12:10.333607505 +0200
@@ -48,7 +48,7 @@ void irq_end_none(struct irq_desc *irq)
static irq_desc_t irq_desc[NR_IRQS];
static DEFINE_PER_CPU(irq_desc_t[NR_LOCAL_IRQS], local_irq_desc);
-struct irq_desc *__irq_to_desc(int irq)
+struct irq_desc *__irq_to_desc(unsigned int irq)
{
if ( irq < NR_LOCAL_IRQS )
return &this_cpu(local_irq_desc)[irq];
