exynos4210_gic_realize() prints the number of cpus into some temporary
buffers, but it only allows 3 bytes space for it. That's plenty:
existing machines will only ever set this value to EXYNOS4210_NCPUS
(2). But the compiler can't always figure that out, so some[*] gcc9
versions emit -Wformat-truncation warnings.
We can fix that by hinting the constraint to the compiler with a
suitably placed assert().
[*] The bizarre thing here, is that I've long gotten these warnings
compiling in a 32-bit x86 container as host - Fedora 30 with
gcc-9.2.1-1.fc30.i686 - but it compiles just fine on my normal
x86_64 host - Fedora 30 with and gcc-9.2.1-1.fc30.x86_64.
Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
Changes since v1:
* Used an assert to hint the compiler, instead of increasing the
buffer size.
---
hw/intc/exynos4210_gic.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/hw/intc/exynos4210_gic.c b/hw/intc/exynos4210_gic.c
index a1b699b6ba..ed4d8482e3 100644
--- a/hw/intc/exynos4210_gic.c
+++ b/hw/intc/exynos4210_gic.c
@@ -314,6 +314,14 @@ static void exynos4210_gic_realize(DeviceState *dev, Error
**errp)
EXYNOS4210_EXT_GIC_DIST_REGION_SIZE);
for (i = 0; i < s->num_cpu; i++) {
+ /*
+ * This clues in gcc that our on-stack buffers do, in fact
+ * have enough room for the cpu numbers. gcc 9.2.1 on 32-bit
+ * x86 doesn't figure this out, otherwise and gives spurious
+ * warnings.
+ */
+ assert(i <= EXYNOS4210_NCPUS);
+
/* Map CPU interface per SMP Core */
sprintf(cpu_alias_name, "%s%x", cpu_prefix, i);
memory_region_init_alias(&s->cpu_alias[i], obj,
--
2.23.0
