On Fri, 4 Oct 2019 at 04:10, David Gibson <[email protected]> wrote: > > exynos4210_gic_realize() prints the number of cpus into some temporary > buffers, but it only allows 3 bytes space for it. That's plenty - I'm > pretty sure that existing machines will only ever set this value to 2 > (EXYNOS4210_NCPUS). But the compiler can't really be expected to figure > that out. > > Some[*] gcc9 versions therefore emit -Wformat-truncation warnings. Fix > that by allowing more space in the temporary buffers - these are on stack > very briefly before being essentially strdup()ed inside the memory region > code, so there's not much cost to doing so. > > [*] 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 <[email protected]> > --- > hw/intc/exynos4210_gic.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/hw/intc/exynos4210_gic.c b/hw/intc/exynos4210_gic.c > index a1b699b6ba..2e5e47f9ec 100644 > --- a/hw/intc/exynos4210_gic.c > +++ b/hw/intc/exynos4210_gic.c > @@ -290,8 +290,8 @@ static void exynos4210_gic_realize(DeviceState *dev, > Error **errp) > SysBusDevice *sbd = SYS_BUS_DEVICE(obj); > const char cpu_prefix[] = "exynos4210-gic-alias_cpu"; > const char dist_prefix[] = "exynos4210-gic-alias_dist"; > - char cpu_alias_name[sizeof(cpu_prefix) + 3]; > - char dist_alias_name[sizeof(cpu_prefix) + 3]; > + char cpu_alias_name[sizeof(cpu_prefix) + 10]; > + char dist_alias_name[sizeof(cpu_prefix) + 10]; > SysBusDevice *gicbusdev; > uint32_t i;
If we assert() that num_cpu is always <= EXYNOS4210_NCPUS is that sufficient to clue gcc in that the buffer can't overflow? thanks -- PMM
