Re: [PATCH 2/2] fuzz: log the arguments used to initialize QEMU

[Thomas Huth <thuth@redhat.com>]

On 17/01/2021 21.10, Alexander Bulekov wrote:
> This is useful for building reproducers. Instead checking the code or
> the QEMU_FUZZ_ARGS, the arguments are at the top of the crash log.
> 
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> ---
>   tests/qtest/fuzz/fuzz.c | 11 ++++++++++-
>   1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/qtest/fuzz/fuzz.c b/tests/qtest/fuzz/fuzz.c
> index 238866a037..496d11a231 100644
> --- a/tests/qtest/fuzz/fuzz.c
> +++ b/tests/qtest/fuzz/fuzz.c
> @@ -159,6 +159,8 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp)
>       char *target_name;
>       const char *bindir;
>       char *datadir;
> +    GString *cmd_line;
> +    gchar *pretty_cmd_line;
>       bool serialize = false;
>   
>       /* Initialize qgraph and modules */
> @@ -217,7 +219,7 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp)
>       }
>   
>       /* Run QEMU's softmmu main with the fuzz-target dependent arguments */
> -    GString *cmd_line = fuzz_target->get_init_cmdline(fuzz_target);
> +    cmd_line = fuzz_target->get_init_cmdline(fuzz_target);
>       g_string_append_printf(cmd_line, " %s -qtest /dev/null ",
>                              getenv("QTEST_LOG") ? "" : "-qtest-log none");
>   
> @@ -226,6 +228,13 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char ***envp)
>       wordexp(cmd_line->str, &result, 0);
>       g_string_free(cmd_line, true);
>   
> +    if (getenv("QTEST_LOG")) {
> +        pretty_cmd_line  = g_strjoinv(" ", result.we_wordv + 1);
> +        printf("Starting %s with Arguments: %s\n",
> +                result.we_wordv[0], pretty_cmd_line);
> +        g_free(pretty_cmd_line);
> +    }
> +
>       qemu_init(result.we_wordc, result.we_wordv, NULL);
>   
>       /* re-enable the rcu atfork, which was previously disabled in qemu_init */
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>