Re: [PATCH] pbl: export pbl_verify_piggy function

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hi,

On 1/5/26 9:36 AM, Ahmad Fatoum wrote:
> To support barebox proper being an ELF binary, we will want to verify it
> all at once and then decompress the segments one by one.
> 
> Export the necessary API to prepare for this.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@barebox.org>

Please dismiss. I like the way of decompressing and fixing up in place more.

Cheers,
Ahmad

> ---
>  include/pbl.h |  3 +++
>  pbl/decomp.c  | 42 ++++++++++++++++++++++++++++--------------
>  2 files changed, 31 insertions(+), 14 deletions(-)
> 
> diff --git a/include/pbl.h b/include/pbl.h
> index b330010562c4..6fe868e14abc 100644
> --- a/include/pbl.h
> +++ b/include/pbl.h
> @@ -14,7 +14,10 @@
>  extern unsigned long free_mem_ptr;
>  extern unsigned long free_mem_end_ptr;
>  
> +void pbl_verify_piggy(void *compressed_start, unsigned int len);
>  void pbl_barebox_uncompress(void *dest, void *compressed_start, unsigned int len);
> +long pbl_barebox_uncompress_noverify(void *dest, void *compressed_start,
> +				     unsigned int len);
>  
>  void fdt_find_mem(const void *fdt, unsigned long *membase, unsigned long *memsize);
>  int fdt_fixup_mem(void *fdt, unsigned long membase[], unsigned long memsize[], size_t num);
> diff --git a/pbl/decomp.c b/pbl/decomp.c
> index ebdf81ddfbe5..ba722acdd174 100644
> --- a/pbl/decomp.c
> +++ b/pbl/decomp.c
> @@ -89,24 +89,38 @@ int pbl_barebox_verify(const void *compressed_start, unsigned int len,
>  	return memcmp(hash, computed_hash, SHA256_DIGEST_SIZE);
>  }
>  
> -void pbl_barebox_uncompress(void *dest, void *compressed_start, unsigned int len)
> +void pbl_verify_piggy(void *compressed_start, unsigned int len)
>  {
>  	uint32_t pbl_hash_len;
>  	void *pbl_hash_start, *pbl_hash_end;
>  
> -	if (IS_ENABLED(CONFIG_PBL_VERIFY_PIGGY)) {
> -		pbl_hash_start = sha_sum;
> -		pbl_hash_end = sha_sum_end;
> -		pbl_hash_len = pbl_hash_end - pbl_hash_start;
> -		if (pbl_barebox_verify(compressed_start, len, pbl_hash_start,
> -				       pbl_hash_len) != 0) {
> -			putc_ll('!');
> -			panic("hash mismatch, refusing to decompress");
> -		}
> +	if (!IS_ENABLED(CONFIG_PBL_VERIFY_PIGGY)) {
> +		pr_debug("Verifying piggybacked barebox proper disabled\n");
> +		return;
>  	}
>  
> -	decompress((void *)compressed_start,
> -			len,
> -			NULL, NULL,
> -			dest, NULL, errorfn);
> +	pbl_hash_start = sha_sum;
> +	pbl_hash_end = sha_sum_end;
> +	pbl_hash_len = pbl_hash_end - pbl_hash_start;
> +	if (pbl_barebox_verify(compressed_start, len, pbl_hash_start,
> +			       pbl_hash_len) != 0) {
> +		putc_ll('!');
> +		panic("hash mismatch, refusing to decompress");
> +	}
> +}
> +
> +
> +long pbl_barebox_uncompress_noverify(void *dest, void *compressed_start,
> +				     unsigned int len)
> +{
> +	long pos;
> +	return decompress((void *)compressed_start,
> +			  len, NULL, NULL,
> +			  dest, &pos, errorfn) ?: pos;
> +}
> +
> +void pbl_barebox_uncompress(void *dest, void *compressed_start, unsigned int len)
> +{
> +	pbl_verify_piggy(compressed_start, len);
> +	pbl_barebox_uncompress_noverify(dest, compressed_start, len);
>  }

-- 
Pengutronix e.K.                  |                             |
Steuerwalder Str. 21              | http://www.pengutronix.de/  |
31137 Hildesheim, Germany         | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686  | Fax:   +49-5121-206917-5555 |