Re: [Qemu-devel] [RFC 07/19] fuzz: Modify libqtest to directly invoke qtest.c

[Thomas Huth <thuth@redhat.com>]

On 25/07/2019 05.23, Oleinik, Alexander wrote:
> libqtest directly invokes the qtest client and exposes a function to
> accept responses.
> 
> Signed-off-by: Alexander Oleinik <alxndr@bu.edu>
> ---
>  tests/libqtest.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++-
>  tests/libqtest.h |  6 ++++++
>  2 files changed, 58 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/libqtest.c b/tests/libqtest.c
> index 3c5c3f49d8..a68a7287cb 100644
> --- a/tests/libqtest.c
> +++ b/tests/libqtest.c
> @@ -30,12 +30,18 @@
>  #include "qapi/qmp/qjson.h"
>  #include "qapi/qmp/qlist.h"
>  #include "qapi/qmp/qstring.h"
> +#ifdef CONFIG_FUZZ
> +#include "sysemu/qtest.h"
> +#endif
>  
>  #define MAX_IRQ 256
>  #define SOCKET_TIMEOUT 50
>  #define SOCKET_MAX_FDS 16
>  
>  QTestState *global_qtest;
> +#ifdef CONFIG_FUZZ
> +static GString *recv_str;
> +#endif
>  
>  struct QTestState
>  {
> @@ -316,6 +322,20 @@ QTestState *qtest_initf(const char *fmt, ...)
>      va_end(ap);
>      return s;
>  }
> +#ifdef CONFIG_FUZZ
> +QTestState *qtest_init_fuzz(const char *extra_args, int *sock_fd)
> +{
> +    QTestState *qts;
> +    qts = g_new(QTestState, 1);
> +    qts->wstatus = 0;
> +    for (int i = 0; i < MAX_IRQ; i++) {
> +        qts->irq_level[i] = false;
> +    }
> +    qts->big_endian = qtest_query_target_endianness(qts);
> +
> +    return qts;
> +}
> +#endif
>  
>  QTestState *qtest_init_with_serial(const char *extra_args, int *sock_fd)
>  {
> @@ -379,9 +399,18 @@ static void socket_sendf(int fd, const char *fmt, va_list ap)
>  {
>      gchar *str = g_strdup_vprintf(fmt, ap);
>      size_t size = strlen(str);
> +#ifdef CONFIG_FUZZ
> +    // Directly call qtest_process_inbuf in the qtest server
> +    GString *gstr = g_string_new_len(str, size);
> +	/* printf(">>> %s",gstr->str); */

Please check your patches with scripts/checkpatch.pl - e.g. don't use
TABs for indentation like in the above line, don't use //-comments, etc.

> +    qtest_server_recv(gstr);
> +    g_string_free(gstr, true);
> +    g_free(str);
> +#else
>  
>      socket_send(fd, str, size);
>      g_free(str);
> +#endif
>  }
>  
>  static void GCC_FMT_ATTR(2, 3) qtest_sendf(QTestState *s, const char *fmt, ...)
> @@ -433,6 +462,12 @@ static GString *qtest_recv_line(QTestState *s)
>      size_t offset;
>      char *eol;
>  
> +#ifdef CONFIG_FUZZ
> +    eol = strchr(recv_str->str, '\n');
> +    offset = eol - recv_str->str;
> +    line = g_string_new_len(recv_str->str, offset);
> +    g_string_erase(recv_str, 0, offset + 1);
> +#else
>      while ((eol = strchr(s->rx->str, '\n')) == NULL) {
>          ssize_t len;
>          char buffer[1024];
> @@ -453,7 +488,7 @@ static GString *qtest_recv_line(QTestState *s)
>      offset = eol - s->rx->str;
>      line = g_string_new_len(s->rx->str, offset);
>      g_string_erase(s->rx, 0, offset + 1);
> -
> +#endif
>      return line;
>  }
>  
> @@ -797,6 +832,9 @@ char *qtest_hmp(QTestState *s, const char *fmt, ...)
>  
>  const char *qtest_get_arch(void)
>  {
> +#ifdef CONFIG_FUZZ
> +    return "i386";
> +#endif

Hard-coding "i386" is quite ugly ... it's ok for an RFC patch, but I
think this should be fixed in the final version of the patches. Maybe
you could use TARGET_NAME instead?

>      const char *qemu = qtest_qemu_binary();
>      const char *end = strrchr(qemu, '/');
>  
> @@ -1339,3 +1377,16 @@ void qmp_assert_error_class(QDict *rsp, const char *class)
>  
>      qobject_unref(rsp);
>  }
> +#ifdef CONFIG_FUZZ
> +void qtest_clear_rxbuf(QTestState *s){

For functions, the curly brace should start on a new line.

> +    g_string_set_size(recv_str,0);
> +}

 Thomas