Re: [Qemu-devel] [PATCH 1/3] fw_cfg: fix -boot bootsplash error checking

[Markus Armbruster <armbru@redhat.com>]

Li Qiang <liq3ea@163.com> writes:

> fw_cfg_bootsplash() gets option parameter "splash-time"
> with qemu_opt_get(), then converts it to an integer by hand.
> It neglects to check that conversion for errors. This is
> needlessly complicated and error-prone. But as "splash-time
> not specified" is not the same as "splash-time=T" for any T,
> we need use qemu_opt_get() to check if splash time exists.
> This patch also make the qemu exit when finding or loading
> splash file failed.
>
> Signed-off-by: Li Qiang <liq3ea@163.com>
> ---
>  hw/nvram/fw_cfg.c | 40 ++++++++++++++++------------------------
>  vl.c              |  2 +-
>  2 files changed, 17 insertions(+), 25 deletions(-)
>
> diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
> index 946f765f7f..78f43dad93 100644
> --- a/hw/nvram/fw_cfg.c
> +++ b/hw/nvram/fw_cfg.c
> @@ -118,55 +118,47 @@ error:
>  
>  static void fw_cfg_bootsplash(FWCfgState *s)
>  {
> -    int boot_splash_time = -1;
>      const char *boot_splash_filename = NULL;
> -    char *p;
> +    const char *boot_splash_time = NULL;
>      char *filename, *file_data;
>      gsize file_size;
>      int file_type;
> -    const char *temp;
>  
>      /* get user configuration */
>      QemuOptsList *plist = qemu_find_opts("boot-opts");
>      QemuOpts *opts = QTAILQ_FIRST(&plist->head);
> -    if (opts != NULL) {
> -        temp = qemu_opt_get(opts, "splash");
> -        if (temp != NULL) {
> -            boot_splash_filename = temp;
> -        }
> -        temp = qemu_opt_get(opts, "splash-time");
> -        if (temp != NULL) {
> -            p = (char *)temp;
> -            boot_splash_time = strtol(p, &p, 10);
> -        }
> -    }
> +    boot_splash_filename = qemu_opt_get(opts, "splash");
> +    boot_splash_time = qemu_opt_get(opts, "splash-time");
>  
>      /* insert splash time if user configurated */
> -    if (boot_splash_time >= 0) {
> +    if (boot_splash_time) {
> +        int64_t bst_val = qemu_opt_get_number(opts, "splash-time", -1);
>          /* validate the input */
> -        if (boot_splash_time > 0xffff) {
> -            error_report("splash time is big than 65535, force it to 65535.");
> -            boot_splash_time = 0xffff;
> +        if (bst_val < 0 || bst_val > 0xffff) {
> +            error_report("splash time is invalid,"
> +                         "it should be a value between 0 and 65535");

Let's match the parameter name exactly: "splash-time is invalid, ..."

> +            exit(1);
>          }
>          /* use little endian format */
> -        qemu_extra_params_fw[0] = (uint8_t)(boot_splash_time & 0xff);
> -        qemu_extra_params_fw[1] = (uint8_t)((boot_splash_time >> 8) & 0xff);
> +        qemu_extra_params_fw[0] = (uint8_t)(bst_val & 0xff);
> +        qemu_extra_params_fw[1] = (uint8_t)((bst_val >> 8) & 0xff);
>          fw_cfg_add_file(s, "etc/boot-menu-wait", qemu_extra_params_fw, 2);
>      }
>  
>      /* insert splash file if user configurated */
> -    if (boot_splash_filename != NULL) {
> +    if (boot_splash_filename) {
>          filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, boot_splash_filename);
>          if (filename == NULL) {
> -            error_report("failed to find file '%s'.", boot_splash_filename);
> -            return;
> +            error_report("failed to find file '%s'", boot_splash_filename);
> +            exit(1);
>          }
>  
>          /* loading file data */
>          file_data = read_splashfile(filename, &file_size, &file_type);
>          if (file_data == NULL) {
>              g_free(filename);
> -            return;
> +            error_report("failed to read file '%s'", boot_splash_filename);

Drop this error_report(), please.  read_splashfile() already reports the
failure more usefully.

> +            exit(1);
>          }
>          g_free(boot_splash_filedata);
>          boot_splash_filedata = (uint8_t *)file_data;
> diff --git a/vl.c b/vl.c
> index fa25d1ae2d..96ac0ddcf6 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -336,7 +336,7 @@ static QemuOptsList qemu_boot_opts = {
>              .type = QEMU_OPT_STRING,
>          }, {
>              .name = "splash-time",
> -            .type = QEMU_OPT_STRING,
> +            .type = QEMU_OPT_NUMBER,
>          }, {
>              .name = "reboot-timeout",
>              .type = QEMU_OPT_STRING,

With these minor error reporting improvements:
Reviewed-by: Markus Armbruster <armbru@redhat.com>