Re: [PATCH 9/9] target/i386: Replace sprintf() by snprintf()

[Peter Maydell]

On Thu, 11 Apr 2024 at 11:44, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>
> sprintf() is deprecated on Darwin since macOS 13.0 / XCode 14.1,
> resulting in painful developper experience. Use snprintf() instead.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  target/i386/kvm/kvm.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
> index e68cbe9293..a46d1426bf 100644
> --- a/target/i386/kvm/kvm.c
> +++ b/target/i386/kvm/kvm.c
> @@ -5335,7 +5335,8 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run 
> *run)
>      case KVM_EXIT_NOTIFY:
>          ctx_invalid = !!(run->notify.flags & KVM_NOTIFY_CONTEXT_INVALID);
>          state = KVM_STATE(current_accel());
> -        sprintf(str, "Encounter a notify exit with %svalid context in"
> +        snprintf(str, sizeof(str),
> +                     "Encounter a notify exit with %svalid context in"
>                       " guest. There can be possible misbehaves in guest."
>                       " Please have a look.", ctx_invalid ? "in" : "");
>          if (ctx_invalid ||
> --

This is a case where I think we would be better off with
g_strdup_printf():

 * the buffer declaration is a long way away from its use
 * the string is long and it's not trivial to confirm that
   it will fit in the buffer
 * it's quite plausible somebody will come along later to
   clean up the wording of the error message and not notice
   they need to enlarge the buffer
 * it's only for printing a warning, so it's not going to
   be in a hot codepath

thanks
-- PMM