[PATCH 5/5] sandbox: set retval early in board_fdt_blob_setup()

[Simon Glass]

Hi Evgeny,

On Mon, 2 Dec 2024 at 06:46, Evgeny Bachinin
<EABachinin at salutedevices.com> wrote:
>
> Bug:
> nobody sets 'ret' to non-error value inside board_fdt_blob_setup()
> in case, when gd->fdt_blob has been initialized before calling the
> board_fdt_blob_setup() (say, due to CONFIG_OF_EMBED=y)
>
> Reproduced with CONFIG_OF_EMBED=y && BLOBLIST=n.
>   ```
>     $ ./u-boot
>     initcall: 0000000000078e05 (relocated to 000061138d2c7e05)
>     initcall: 0000000000117b12 (relocated to 000061138d366b12)
>       fdtdec_setup():
>             gd->fdt_blob = dtb_dt_embedded()
>       fdtdec_setup():
>             gd->fdt_blob = board_fdt_blob_setup(&ret);
>
>         board_fdt_blob_setup():380 ret:-2 gd->fdt_blob:0x61138d4db310
>                 if (gd->fdt_blob)
>                         return (void *)gd->fdt_blob;
>
>     initcall failed at call 0000000000117b12 (err=-2: No such file \
>        or directory)
>     ### ERROR ### Please RESET the board ###
>   ```
>
> Patch moves code, zeroizing the 'ret', before checking the fdt_blob.
>
> Fixes: d8289e7dfe5 ("sandbox: fdt: Avoid overwriting an existing fdt")
> Signed-off-by: Evgeny Bachinin <EABachinin at salutedevices.com>
> ---
>  arch/sandbox/cpu/cpu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/sandbox/cpu/cpu.c b/arch/sandbox/cpu/cpu.c
> index d1c4dcf0764fb37ec99585a3db16fa34c3a54dac..7e93377e87e75b0fb92a8cf139b4a731a88a6a7b 100644
> --- a/arch/sandbox/cpu/cpu.c
> +++ b/arch/sandbox/cpu/cpu.c
> @@ -377,10 +377,10 @@ void *board_fdt_blob_setup(int *ret)
>         int err;
>         int fd;
>
> +       *ret = 0;
>         if (gd->fdt_blob)
>                 return (void *)gd->fdt_blob;
>         blob = map_sysmem(CONFIG_SYS_FDT_LOAD_ADDR, 0);
> -       *ret = 0;
>         if (!state->fdt_fname) {
>                 err = setup_auto_tree(blob);
>                 if (!err)
>
> --
> 2.34.1
>

Reviewed-by: Simon Glass <sjg at chromium.org>

But note for the future we have:

https://patchwork.ozlabs.org/project/uboot/patch/20241102174944.412088-2-sjg@chromium.org/

Regards,
Simon