[U-Boot] [PATCH v2 3/3] fastboot: Check if partition really exist in getvar_has_slot()

[Sam Protsenko <semen.protsenko@linaro.org>]

Hi Tom,

We have broken fastboot right now... Can we please apply this series,
so that it appears in v2019.07?

Thanks!

On Thu, Jun 13, 2019 at 12:14 AM Sam Protsenko
<semen.protsenko@linaro.org> wrote:
>
> From: Igor Opaniuk <igor.opaniuk@toradex.com>
>
> Currently getvar_has_slot() invocation for "boot" and "system"
> partitions always returns affirmative response regardless the fact of
> existence of these partitions, which leads to impossibility to flash them
> on old non-A/B AOSP setups, where _a/_b suffixes aren't used:
>
> $ fastboot flash boot boot.img
> Sending 'boot__a' (11301 KB)    OKAY [  0.451s]
> Writing 'boot__a'               FAILED (remote: 'cannot find partition')
> fastboot: error: Command failed
>
> Although partition layout is:
> -> part list mmc 0
> Partition Map for MMC device 0  --   Partition Type: EFI
>
> Part    Start LBA       End LBA         Name
>         Attributes
>         Type GUID
>         Partition GUID
>   1     0x00000800      0x000107ff      "boot"
>         attrs:  0x0000000000000000
>         type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
>         guid:   ea2e2470-db4a-d646-b828-10167f736d63
>   2     0x00010800      0x000127ff      "environment"
>         attrs:  0x0000000000000000
>         type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
>         guid:   10a819d2-6004-3d48-bd87-114e2a796db9
>   3     0x00012800      0x0001a7ff      "recovery"
>         attrs:  0x0000000000000000
>         type:   ebd0a0a2-b9e5-4433-87c0-68b6b72699c7
>         guid:   9ea116e4-8a34-0c48-8cf5-2fe9480f56cd
>   4     0x0001a800      0x0031a7ff      "system"
>         attrs:  0x0000000000000000
> ......
>
> This patch adds checks of existence for requested partitions
> on eMMC/NAND.
>
> Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> ---
>  drivers/fastboot/fb_getvar.c | 26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/fastboot/fb_getvar.c b/drivers/fastboot/fb_getvar.c
> index b23880089e..563bda0088 100644
> --- a/drivers/fastboot/fb_getvar.c
> +++ b/drivers/fastboot/fb_getvar.c
> @@ -179,11 +179,29 @@ static void getvar_slot_suffixes(char *var_parameter, char *response)
>
>  static void getvar_has_slot(char *part_name, char *response)
>  {
> -       if (part_name && (!strcmp(part_name, "boot") ||
> -                         !strcmp(part_name, "system")))
> +       char part_name_wslot[PART_NAME_LEN];
> +       size_t len;
> +       int r;
> +
> +       if (!part_name)
> +               goto no;
> +
> +       /* Append "_a" prefix to part_name */
> +       len = strlcpy(part_name_wslot, part_name, PART_NAME_LEN - 3);
> +       if (len > PART_NAME_LEN - 3) {
> +               fastboot_fail("too long partition name", response);
> +               return;
> +       }
> +       strcat(part_name_wslot, "_a");
> +
> +       /* Check if this partition exists */
> +       r = getvar_get_part_info(part_name_wslot, response, NULL);
> +       if (r >= 0) {
>                 fastboot_okay("yes", response);
> -       else
> -               fastboot_okay("no", response);
> +               return;
> +       }
> +no:
> +       fastboot_okay("no", response);
>  }
>
>  #if CONFIG_IS_ENABLED(FASTBOOT_FLASH_MMC)
> --
> 2.20.1
>