From 1625073289b7940477031d3e98ea8c829a699df5 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Mon, 2 Dec 2019 17:08:06 +1100 Subject: [PATCH] exynos4210_gic: Suppress gcc9 format-truncation warnings MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Richard Henderson [PMM: deleted stray blank line] Signed-off-by: Peter Maydell --- hw/intc/exynos4210_gic.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/hw/intc/exynos4210_gic.c b/hw/intc/exynos4210_gic.c index a1b699b6ba..9a84d8522e 100644 --- a/hw/intc/exynos4210_gic.c +++ b/hw/intc/exynos4210_gic.c @@ -293,6 +293,7 @@ static void exynos4210_gic_realize(DeviceState *dev, Error **errp) char cpu_alias_name[sizeof(cpu_prefix) + 3]; char dist_alias_name[sizeof(cpu_prefix) + 3]; SysBusDevice *gicbusdev; + uint32_t n = s->num_cpu; uint32_t i; s->gic = qdev_create(NULL, "arm_gic"); @@ -313,7 +314,13 @@ static void exynos4210_gic_realize(DeviceState *dev, Error **errp) memory_region_init(&s->dist_container, obj, "exynos4210-dist-container", 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(n <= EXYNOS4210_NCPUS); + for (i = 0; i < n; i++) { /* Map CPU interface per SMP Core */ sprintf(cpu_alias_name, "%s%x", cpu_prefix, i); memory_region_init_alias(&s->cpu_alias[i], obj, -- 2.11.0