Re: [PATCH 1/4] fuzz: add datadir for oss-fuzz compatability

[Philippe Mathieu-Daudé]

On 5/12/20 5:01 AM, Alexander Bulekov wrote:
> This allows us to keep pc-bios in executable_dir/pc-bios, rather than
> executable_dir/../pc-bios, which is incompatible with oss-fuzz' file
> structure.
>
> Signed-off-by: Alexander Bulekov <address@hidden>
> ---
>   include/sysemu/sysemu.h |  2 ++
>   softmmu/vl.c            |  2 +-
>   tests/qtest/fuzz/fuzz.c | 15 +++++++++++++++
>   3 files changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
> index ef81302e1a..cc96b66fc9 100644
> --- a/include/sysemu/sysemu.h
> +++ b/include/sysemu/sysemu.h
> @@ -15,6 +15,8 @@ extern const char *qemu_name;
>   extern QemuUUID qemu_uuid;
>   extern bool qemu_uuid_set;
>   
> +void qemu_add_data_dir(const char *path);
> +
>   void qemu_add_exit_notifier(Notifier *notify);
>   void qemu_remove_exit_notifier(Notifier *notify);
>   
> diff --git a/softmmu/vl.c b/softmmu/vl.c
> index afd2615fb3..c71485a965 100644
> --- a/softmmu/vl.c
> +++ b/softmmu/vl.c
> @@ -1993,7 +1993,7 @@ char *qemu_find_file(int type, const char *name)
>       return NULL;
>   }
>   
> -static void qemu_add_data_dir(const char *path)
> +void qemu_add_data_dir(const char *path)
>   {
>       int i;
>   
> diff --git a/tests/qtest/fuzz/fuzz.c b/tests/qtest/fuzz/fuzz.c
> index f5c923852e..33365c3782 100644
> --- a/tests/qtest/fuzz/fuzz.c
> +++ b/tests/qtest/fuzz/fuzz.c
> @@ -137,6 +137,7 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char 
> ***envp)
>   {
>   
>       char *target_name;
> +    char *dir;
>   
>       /* Initialize qgraph and modules */
>       qos_graph_init();
> @@ -147,6 +148,20 @@ int LLVMFuzzerInitialize(int *argc, char ***argv, char 
> ***envp)
>       target_name = strstr(**argv, "-target-");
>       if (target_name) {        /* The binary name specifies the target */
>           target_name += strlen("-target-");
> +        /*
> +         * With oss-fuzz, the executable is kept in the root of a directory (we
> +         * cannot assume the path). All data (including bios binaries) must be
> +         * in the same dir, or a subdir. Thus, we cannot place the pc-bios so
> +         * that it would be in exec_dir/../pc-bios.
> +         * As a workaround, oss-fuzz allows us to use argv[0] to get the
> +         * location of the executable. Using this we add exec_dir/pc-bios to
> +         * the datadirs.

I don't understand well the problem. How do you run it?

> +         */
> +        dir = g_build_filename(g_path_get_dirname(**argv), "pc-bios", NULL);
> +        if (g_file_test(dir, G_FILE_TEST_IS_DIR)) {
> +            qemu_add_data_dir(dir);
> +        }
> +        g_free(dir);
>       } else if (*argc > 1) {  /* The target is specified as an argument */
>           target_name = (*argv)[1];
>           if (!strstr(target_name, "--fuzz-target=")) {