Re: [PATCH] fuzz: Disable QEMU's signal handlers

[Darren Kenny]

Hi Alex,

This mentions the use of atexit() to perform some cleanup, but I'm not
seeing that being added here, should it be?

Thanks,

Darren.

On Tuesday, 2020-10-13 at 11:29:20 -04, Alexander Bulekov wrote:
> With the fuzzer, we never call main_loop_should_exit, since we manually
> call main_loop_wait. This means that the only way to terminate the
> fuzzer is with SIGKILL. Disable the signal handlers, so there are
> reasonable ways to terminate the fuzzer and use atexit() to clean-up
> after the fuzzer.
>
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> ---
>  tests/qtest/fuzz/fuzz.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/tests/qtest/fuzz/fuzz.c b/tests/qtest/fuzz/fuzz.c
> index d926c490c5..eb0070437f 100644
> --- a/tests/qtest/fuzz/fuzz.c
> +++ b/tests/qtest/fuzz/fuzz.c
> @@ -217,5 +217,13 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char 
> ***envp)
>      /* re-enable the rcu atfork, which was previously disabled in qemu_init 
> */
>      rcu_enable_atfork();
>  
> +    /*
> +     * Disable QEMU's signal handlers, since we manually control the 
> main_loop,
> +     * and don't check for main_loop_should_exit
> +     */
> +    signal(SIGINT, SIG_DFL);
> +    signal(SIGHUP, SIG_DFL);
> +    signal(SIGTERM, SIG_DFL);
> +
>      return 0;
>  }
> -- 
> 2.28.0